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Problems that are “in the shadow” of p-p Optics design Collective effects – lower charge per bunch, fewer bunches – Including impedance-driven, beam-beam, electron cloud Stored beam energy – Not as large as in p-p (but still large …) – Nevertheless collimation efficiency is likely to be much lower! J.M. Jowett, M. Schaumann, FCC Week 2015, Washington DC, 24 March
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1
FCC-hh as a Heavy-Ion Collider
John Jowett CERN Michaela Schaumann RWTH-Aachen amp CERN
Acknowledgements A Dainese (INFN Padova) B Holzer (CERN)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
times14gt 8 PeV
2
General FCC-hh Parameters
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Units Injection Collision
Circumference [km] 100 100
Main dipole strength [T] 10 16
Bending radius [m] 10424 10424
Proton equivalent energy [TeV] 33 50
Pb energy [TeV] 270 4100
Pb energynucleon [TeV] 13 197
Pb-Pb CM energy [TeV] 8200
Pb-Pb CM energynucleon pair [TeV] 394
p-Pb CM energy [TeV] 905
p-Pb CM energynucleon pair [TeV] 628
In relation to FCC-hh assumed working as p-p collider consider Pb-Pb and p-Pb collisions at maximum energy
3
Problems that are ldquoin the shadowrdquo of p-pbull Optics designbull Collective effects
ndash lower charge per bunch fewer bunchesndash Including impedance-driven beam-beam electron cloud
bull Stored beam energyndash Not as large as in p-p (but still large hellip)ndash Nevertheless collimation efficiency is likely to be much
lower
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
4
What is new with heavy-ion beams wrt protonsbull Synchrotron radiation damping is twice as fast
ndash Free natural beam cooling not limited by beam-beam tune-shift
bull Pb nuclei are accompanied by intense fluxes of high energy quasi-real photonsndash (Physics interest hellip)ndash Leads to powerful secondary beams emerging from collision
pointndash Extreme luminosity burn-off from electromagnetic cross-
sectionsndash More complicated interactions with collimators
bull Stronger intra-beam scattering ultimately limits emittanceJM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
5
4 in the same magnetic fieldZm
5
Physics with ions at FCCbull Physics opportunities with heavy ion beams at the FCC (AA pA)
are investigated by a dedicated WG within the FCC-hh group 4 workshops held (httpsindicocernchevent331669 and links therein)
bull Main directionsndash Quark-Gluon Plasma studies
bull larger size and stronger expansion better sensitivity to QGP-fluid propertiesbull higher temperature large thermal charm production full melting of quarkoniabull new hard probes available (eg top quarks)
ndash Saturation of small-x gluon densities (with pA and eA) reach down xBjorken~10-6 (one order of magnitude smaller than at LHC)
ndash Ion beams photon-induced collisions (g+g g+A) saturation and EW studies
bull More informationndash Presentation on eA (and AA) physics by MPloskon (this workshop)ndash httparXiv14077649 ( Nuclear Physics A 931 2014 1163ndash1168 )ndash httpstwikicernchtwikibinviewLHCPhysicsHeavyIons
Slide from A DaineseJM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Just two examples
6
bull Significantly larger initial temperature Could reach close to 1 GeVndash Abundant ldquothermalrdquo production of c-
cbar pairs in the mediumndash Full suppression of quarkonia (Y(1S)
may not be suppressed at LHC)bull Anisotropic flow measurements
become sensitive to currently-inaccessible properties of the QGP eg temperature dependence of viscosity
Based on B-W Zhang et al PRC77 (2008)
dNcc
dy
50
3520
LHC FCC
G Denicol in httpsindicocernchevent331669 Slide from A DaineseJM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
7
Previous references on AA amp pA in FCC-hhbull M Schaumann Ions at the Future Hadron Collider 16-17 Dec
2013 CERN httpsindicocernchevent288576 bull M Schaumann FCC Study Kick-off Meeting 12-15 Feb 2014
Geneva httpsindicocernchevent282344bull M Schaumann Ions at the Future Hadron Collider
httpsindicocernchevent331669 (update to 100 km)
bull M Schaumann Chapter 9 of thesis submitted to RWTH Aachenbull M Schaumann ldquoPotential performance for Pb-Pb p-Pb and p-p
collisions in a future circular colliderrdquo paper submitted to Phys Rev ST-AB
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Studies focussed on emittance and luminosity evolution with strong radiation damping IBS and luminosity burn-off etc
8
CERN Heavy-Ion Injector Complexbull Present study very conservatively assumes the Pb
injector performance achieved for LHC p-Pb run in 2013
bull Potential upgrades needing studyndash Better ion source ndash Upgradereplacement of LEIR faster cooling higher injection
into PS ndash Degradation of bunches along trains at SPS injection
(alternatives to fixed harmonic acceleration with present200 MHz RF system)
bull LHC as HEB injector into FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Heavy Ion Pre-Accelerator Chain
9JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Straw-man assumption to estimate (conservative) beam parameters and luminosity LHC as it is today but cycling to 33 Z TeV is assumed to be the injector for FCC-hh
Present heavy-ion pre-injectors
LEIRHI source + LINAC 3
Baseline Inject one LHC beam into 14 FCC no waiting ramp immediately
PS
SPS
LHCFCC
10
Pb Beam Parameters in LHC and FCC-hh
LHCDesign
LHC 2011
LHC 2013
FCC-hh
Beam Energy [Z TeV] 7 35 4 50
β-function at the IP [m] 05 10 08 11
No Ions per bunch [] 07 14
Transv normalised emittance [] 15 15
RMS Beam Size at IP [] 159 339 266 88
RMS bunch length [] 794 8
Number of bunches 592 358 358 432
Peak Luminosity [] 1 (Pb-Pb) 110 (p-Pb)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Best injector performance achieved in 2013 p-Pb run
Average beam parameters from 2013 are assumed as VERY conservative baseline for FCC-hh
Improvements are already under study for HL-LHC
Geometric emittance at injection gt protons ndash possible issue for aperture choice
11
Beam and Luminosity Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
During the beams are in collision the instantaneous value of the luminosity will change
The beam evolution with time is obtained by solving a system of four differential equations (dominant effects only shown here more included in simulations)
with
revolution freq no bunchesbeam β-function at IP no particlesbunch geom emittances bunch length
total cross-section IBS growth rate rad damping rateIntensity
Hor Emittance
Ver Emittance
Bunch Length
Analytical solution difficult due to dependence of on
12
Effects on the Emittance ndash a new regime
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Intra-Beam Scattering (IBS) (Synchrotron) Radiation Damping
Emittance Growth Emittance Shrinkage
Growth rate dynamically changing with beam properties
Damping rate is constant for a given energy
IBS is weak for initial beam parameters but increases with decreasing emittance
Multiple small-angle Coulomb scattering within a charged particle beam
A charged particle radiates energy when itis accelerated ie bend on its circular orbit
Fast emittance decrease at the beginning of the fill until IBS becomes strong enough to counteract the radiation damping
Growth Times Unit FCC 50Z TeV
[h] 291
[h] 300
Damping Times Unit FCC 50Z TeV
[h] 024
[h] 049
13
BEAM AND LUMINOSITY EVOLUTION
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Pb-Pb
14
Pb-Pb Beam Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
bull Red tracking simulation taking into account IBS rad damping burn-off hellip
bull Black numerical solution of the ODE system on slide 7 using J Weirsquos analytical IBS formalism
rarr emittances and bunch length become very small
bull Green ddt = 0 artificial longitudinal blow-up to = 8cm
bull Blue artificial longitudinal and transverse blow-up to = 8cm and J Wei Evolution of Hadron Beams under Intrabeam
Scattering ConfProc C930517 (1993) 3651-3653 PAC 1993
Transverse Emittance
Bunch Length
Intensity
15
Pb-Pb Luminosity Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 0006 26
[Hzmb] 0017 73
[] 013 578
Summary for free beam evolution (no artificial blow-up)
If the beam dimensions become too small and artificial blow-up has to be used the luminosity will be affectedbull Peak Enhancement for long blow-up
since long and horizontal IBS are reduced due to larger rarr smaller
bull Reduced luminosity due to blown-up
16
Pb-Pb Average Luminosity
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
= time in collisions rarr to be optimised
= turn-around time = time dump rarr next collisions
Assumption (cycle time FCC without injections) (no injections from LHC)
Average Luminosity per hour
For free beam parameter evolution red case from previous slide
Max at
inst
17
Pb-Pb Integrated Luminosity per Run
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
bull Assumption
bull Consider more LHC injectionsrarr max (= FCC Length)rarr Dwell time at FCC inj plateau
rarr lengthen rarr Particle losses (amp emittance
growth)rarr Loss rate of Pb at injectionrarr Total beam intensity
rarr ltgt ltgt
Int Luminosity per run
Opt Time in Collisions
18
BEAM AND LUMINOSITY EVOLUTION
LHC has shown that p-Pb injecting and ramping with unequal revolution frequencies is feasible This will work for injection (provided we keep independent RF systems) and may not even be necessary in FCC ring
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
p-Pb
19
p-Pb Beam Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam Size Bunch Length
Intensity
Initial conditionsbull Pb-beam as for Pb-Pb operationbull Equal beam sizes σ for p and Pbbull Rad damping
rarr bull IBS scales with bull
rarr Fast Pb burn-off while const
20
p-Pb Luminosity Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 05 213
[Hzmb] 28 1192
[] 487 21068
Peak shifted to later timesrarr p shrinks slower than Pb
Luminosity decay slowerrarr constrarr 1e-Luminosity lifetime 14h
p-Pb Luminosity vs Turn-Around Time
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 201521
Max at
Int Luminosity per run
Opt Time in Collisions
For rarr Optimised fill length = 65h rarr ltgtrun 17 could give higher ltgtrun rarr But uncertainty on prediction
significantly enhanced rarr Early beam aborts and longer inj
times due to lost beams in the LHC reduce ltgtrun
rarr injection and fill times are both in the order of 10h
22
POTENTIAL LIMITATIONS
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
23
Beam-Beam Tune Shift
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam-Beam Parameter per Experiment
Unit LHC Designp-p
LHC DesignPb-Pb
FCCPb-Pb
FCCp-Pb
Initial [ 37 018 037 037
Peak [ 37 018 14 83
Beam-beam tune shift per experimentbull Beam m receives kick from Beam n bull uv =x y
The tune shift due to beam-beam interactions remains well below assumed limit for Pb-Pb but comes close to the limit for Pb in p-Pb collisions
Pb-Pb
p-Pb
γ-γ and γ-A processes in Pb-Pb collisions at FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015 24
2
208208 208
208208
20882 82 82
82 82 8
08208 82 208 82 82 20
20 20
8 8
8 2
8
0
1
7 82
B
BFPP2 Pb Pb Pb Pb 2e 10 mb
FPP1 Pb Pb Pb e 354 b 001235
EMD1 Pb Pb Pb n 20
00Pb
b
2
P
500
0
208208 82 8208 02 2 6 88 2 2
b 000485EMD2 Pb Pb P b 2n
35 b 000970Pb
Each of these makes a secondary beam emerging from the IP with rigidity change
Pb1 11 m mQ Q
Extensively discussed for LHC
Hadronic cross section is 8 b (so much less power in debris)
25
BFPP1 Beam Power in Pb-Pb for FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Countermeasures (eg DS collimators) have to be considered in initial lattice amp hardware design
FCC-PbPb
nominal LHC P 26Wrarr already expected to cause operational problems and poaaible long-term damage
41 PeV
BFPP1 Beam power 17 kW (peak)cP L E
26
Secondary beams from Pb-Pb collisions (Lattice V4 baseline)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
IP
208Pb81+ (BFPP1)208Pb80+ (BFPP2)
206Pb82+ (EMD2)
207Pb82+ (EMD1)
M Schaumann Workshop on Ions at the FCC CERN
27
Smaller Z Ions ndash Impact on hadronic event count
20140922
bull Lower Z possibly higher available from injectors
bull Contribution of ultra-peripheral electromagnetic processes to the total cross-section would be reduced
Increased luminosity lifetime more particles available for hadronic interactions
Reduced secondary beam power emerging from collision point
bull Radiation damping rate does not change much for Zgt60o
o Lower Z beams would put more burn-off into hadronic events
o Worth considering small Z reduction from Pb to eg
(6--8)hadronic
BFPP EMD
hh tot
h
N Ldt N Z
Z
( )(Pb)L ZL
28
Heavy-Ion Beam Parameter Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
29
Heavy-Ion Luminosity Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
30
Future work neededbull Number of active experiments to be considered very carefully
1 or 2 bull Counter measures for (few kW) secondary beams from IPs
ndash Robust collimatorsabsorbers in dispersion suppressorsndash Shower calculations magnet quench risks etc
bull Include heavy ion beams in future evolution of injector chainndash Maximise no of ions injected in colliderndash Do we have to live with present limits in SPS
bull Extend LHC heavy-ion collimation studies to FCCndash Does synchrotron radiation damping solve this for us
bull Vacuum effects
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Collaboration welcome
31
Conclusions and Outlookbull With very conservative assumptions (past LHC Pb
beams) FCC-hh has clear potential for high luminosity nucleus-nucleus and proton-nucleus collisions
bull New highly efficient collider regime of strong radiation damping can be fully exploited with heavy-ion beams
bull Photon-photon and photonuclear processes create powerful secondary beams emerging from IPndash Foresee counter-measures from the start (cf LHC experience)
bull Extreme luminosity burn-off is a fact of nature ndash physics community might want to consider somewhat lower-Z species
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
32
BACKUP SLIDES
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
2
General FCC-hh Parameters
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Units Injection Collision
Circumference [km] 100 100
Main dipole strength [T] 10 16
Bending radius [m] 10424 10424
Proton equivalent energy [TeV] 33 50
Pb energy [TeV] 270 4100
Pb energynucleon [TeV] 13 197
Pb-Pb CM energy [TeV] 8200
Pb-Pb CM energynucleon pair [TeV] 394
p-Pb CM energy [TeV] 905
p-Pb CM energynucleon pair [TeV] 628
In relation to FCC-hh assumed working as p-p collider consider Pb-Pb and p-Pb collisions at maximum energy
3
Problems that are ldquoin the shadowrdquo of p-pbull Optics designbull Collective effects
ndash lower charge per bunch fewer bunchesndash Including impedance-driven beam-beam electron cloud
bull Stored beam energyndash Not as large as in p-p (but still large hellip)ndash Nevertheless collimation efficiency is likely to be much
lower
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
4
What is new with heavy-ion beams wrt protonsbull Synchrotron radiation damping is twice as fast
ndash Free natural beam cooling not limited by beam-beam tune-shift
bull Pb nuclei are accompanied by intense fluxes of high energy quasi-real photonsndash (Physics interest hellip)ndash Leads to powerful secondary beams emerging from collision
pointndash Extreme luminosity burn-off from electromagnetic cross-
sectionsndash More complicated interactions with collimators
bull Stronger intra-beam scattering ultimately limits emittanceJM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
5
4 in the same magnetic fieldZm
5
Physics with ions at FCCbull Physics opportunities with heavy ion beams at the FCC (AA pA)
are investigated by a dedicated WG within the FCC-hh group 4 workshops held (httpsindicocernchevent331669 and links therein)
bull Main directionsndash Quark-Gluon Plasma studies
bull larger size and stronger expansion better sensitivity to QGP-fluid propertiesbull higher temperature large thermal charm production full melting of quarkoniabull new hard probes available (eg top quarks)
ndash Saturation of small-x gluon densities (with pA and eA) reach down xBjorken~10-6 (one order of magnitude smaller than at LHC)
ndash Ion beams photon-induced collisions (g+g g+A) saturation and EW studies
bull More informationndash Presentation on eA (and AA) physics by MPloskon (this workshop)ndash httparXiv14077649 ( Nuclear Physics A 931 2014 1163ndash1168 )ndash httpstwikicernchtwikibinviewLHCPhysicsHeavyIons
Slide from A DaineseJM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Just two examples
6
bull Significantly larger initial temperature Could reach close to 1 GeVndash Abundant ldquothermalrdquo production of c-
cbar pairs in the mediumndash Full suppression of quarkonia (Y(1S)
may not be suppressed at LHC)bull Anisotropic flow measurements
become sensitive to currently-inaccessible properties of the QGP eg temperature dependence of viscosity
Based on B-W Zhang et al PRC77 (2008)
dNcc
dy
50
3520
LHC FCC
G Denicol in httpsindicocernchevent331669 Slide from A DaineseJM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
7
Previous references on AA amp pA in FCC-hhbull M Schaumann Ions at the Future Hadron Collider 16-17 Dec
2013 CERN httpsindicocernchevent288576 bull M Schaumann FCC Study Kick-off Meeting 12-15 Feb 2014
Geneva httpsindicocernchevent282344bull M Schaumann Ions at the Future Hadron Collider
httpsindicocernchevent331669 (update to 100 km)
bull M Schaumann Chapter 9 of thesis submitted to RWTH Aachenbull M Schaumann ldquoPotential performance for Pb-Pb p-Pb and p-p
collisions in a future circular colliderrdquo paper submitted to Phys Rev ST-AB
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Studies focussed on emittance and luminosity evolution with strong radiation damping IBS and luminosity burn-off etc
8
CERN Heavy-Ion Injector Complexbull Present study very conservatively assumes the Pb
injector performance achieved for LHC p-Pb run in 2013
bull Potential upgrades needing studyndash Better ion source ndash Upgradereplacement of LEIR faster cooling higher injection
into PS ndash Degradation of bunches along trains at SPS injection
(alternatives to fixed harmonic acceleration with present200 MHz RF system)
bull LHC as HEB injector into FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Heavy Ion Pre-Accelerator Chain
9JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Straw-man assumption to estimate (conservative) beam parameters and luminosity LHC as it is today but cycling to 33 Z TeV is assumed to be the injector for FCC-hh
Present heavy-ion pre-injectors
LEIRHI source + LINAC 3
Baseline Inject one LHC beam into 14 FCC no waiting ramp immediately
PS
SPS
LHCFCC
10
Pb Beam Parameters in LHC and FCC-hh
LHCDesign
LHC 2011
LHC 2013
FCC-hh
Beam Energy [Z TeV] 7 35 4 50
β-function at the IP [m] 05 10 08 11
No Ions per bunch [] 07 14
Transv normalised emittance [] 15 15
RMS Beam Size at IP [] 159 339 266 88
RMS bunch length [] 794 8
Number of bunches 592 358 358 432
Peak Luminosity [] 1 (Pb-Pb) 110 (p-Pb)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Best injector performance achieved in 2013 p-Pb run
Average beam parameters from 2013 are assumed as VERY conservative baseline for FCC-hh
Improvements are already under study for HL-LHC
Geometric emittance at injection gt protons ndash possible issue for aperture choice
11
Beam and Luminosity Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
During the beams are in collision the instantaneous value of the luminosity will change
The beam evolution with time is obtained by solving a system of four differential equations (dominant effects only shown here more included in simulations)
with
revolution freq no bunchesbeam β-function at IP no particlesbunch geom emittances bunch length
total cross-section IBS growth rate rad damping rateIntensity
Hor Emittance
Ver Emittance
Bunch Length
Analytical solution difficult due to dependence of on
12
Effects on the Emittance ndash a new regime
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Intra-Beam Scattering (IBS) (Synchrotron) Radiation Damping
Emittance Growth Emittance Shrinkage
Growth rate dynamically changing with beam properties
Damping rate is constant for a given energy
IBS is weak for initial beam parameters but increases with decreasing emittance
Multiple small-angle Coulomb scattering within a charged particle beam
A charged particle radiates energy when itis accelerated ie bend on its circular orbit
Fast emittance decrease at the beginning of the fill until IBS becomes strong enough to counteract the radiation damping
Growth Times Unit FCC 50Z TeV
[h] 291
[h] 300
Damping Times Unit FCC 50Z TeV
[h] 024
[h] 049
13
BEAM AND LUMINOSITY EVOLUTION
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Pb-Pb
14
Pb-Pb Beam Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
bull Red tracking simulation taking into account IBS rad damping burn-off hellip
bull Black numerical solution of the ODE system on slide 7 using J Weirsquos analytical IBS formalism
rarr emittances and bunch length become very small
bull Green ddt = 0 artificial longitudinal blow-up to = 8cm
bull Blue artificial longitudinal and transverse blow-up to = 8cm and J Wei Evolution of Hadron Beams under Intrabeam
Scattering ConfProc C930517 (1993) 3651-3653 PAC 1993
Transverse Emittance
Bunch Length
Intensity
15
Pb-Pb Luminosity Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 0006 26
[Hzmb] 0017 73
[] 013 578
Summary for free beam evolution (no artificial blow-up)
If the beam dimensions become too small and artificial blow-up has to be used the luminosity will be affectedbull Peak Enhancement for long blow-up
since long and horizontal IBS are reduced due to larger rarr smaller
bull Reduced luminosity due to blown-up
16
Pb-Pb Average Luminosity
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
= time in collisions rarr to be optimised
= turn-around time = time dump rarr next collisions
Assumption (cycle time FCC without injections) (no injections from LHC)
Average Luminosity per hour
For free beam parameter evolution red case from previous slide
Max at
inst
17
Pb-Pb Integrated Luminosity per Run
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
bull Assumption
bull Consider more LHC injectionsrarr max (= FCC Length)rarr Dwell time at FCC inj plateau
rarr lengthen rarr Particle losses (amp emittance
growth)rarr Loss rate of Pb at injectionrarr Total beam intensity
rarr ltgt ltgt
Int Luminosity per run
Opt Time in Collisions
18
BEAM AND LUMINOSITY EVOLUTION
LHC has shown that p-Pb injecting and ramping with unequal revolution frequencies is feasible This will work for injection (provided we keep independent RF systems) and may not even be necessary in FCC ring
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
p-Pb
19
p-Pb Beam Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam Size Bunch Length
Intensity
Initial conditionsbull Pb-beam as for Pb-Pb operationbull Equal beam sizes σ for p and Pbbull Rad damping
rarr bull IBS scales with bull
rarr Fast Pb burn-off while const
20
p-Pb Luminosity Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 05 213
[Hzmb] 28 1192
[] 487 21068
Peak shifted to later timesrarr p shrinks slower than Pb
Luminosity decay slowerrarr constrarr 1e-Luminosity lifetime 14h
p-Pb Luminosity vs Turn-Around Time
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 201521
Max at
Int Luminosity per run
Opt Time in Collisions
For rarr Optimised fill length = 65h rarr ltgtrun 17 could give higher ltgtrun rarr But uncertainty on prediction
significantly enhanced rarr Early beam aborts and longer inj
times due to lost beams in the LHC reduce ltgtrun
rarr injection and fill times are both in the order of 10h
22
POTENTIAL LIMITATIONS
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
23
Beam-Beam Tune Shift
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam-Beam Parameter per Experiment
Unit LHC Designp-p
LHC DesignPb-Pb
FCCPb-Pb
FCCp-Pb
Initial [ 37 018 037 037
Peak [ 37 018 14 83
Beam-beam tune shift per experimentbull Beam m receives kick from Beam n bull uv =x y
The tune shift due to beam-beam interactions remains well below assumed limit for Pb-Pb but comes close to the limit for Pb in p-Pb collisions
Pb-Pb
p-Pb
γ-γ and γ-A processes in Pb-Pb collisions at FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015 24
2
208208 208
208208
20882 82 82
82 82 8
08208 82 208 82 82 20
20 20
8 8
8 2
8
0
1
7 82
B
BFPP2 Pb Pb Pb Pb 2e 10 mb
FPP1 Pb Pb Pb e 354 b 001235
EMD1 Pb Pb Pb n 20
00Pb
b
2
P
500
0
208208 82 8208 02 2 6 88 2 2
b 000485EMD2 Pb Pb P b 2n
35 b 000970Pb
Each of these makes a secondary beam emerging from the IP with rigidity change
Pb1 11 m mQ Q
Extensively discussed for LHC
Hadronic cross section is 8 b (so much less power in debris)
25
BFPP1 Beam Power in Pb-Pb for FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Countermeasures (eg DS collimators) have to be considered in initial lattice amp hardware design
FCC-PbPb
nominal LHC P 26Wrarr already expected to cause operational problems and poaaible long-term damage
41 PeV
BFPP1 Beam power 17 kW (peak)cP L E
26
Secondary beams from Pb-Pb collisions (Lattice V4 baseline)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
IP
208Pb81+ (BFPP1)208Pb80+ (BFPP2)
206Pb82+ (EMD2)
207Pb82+ (EMD1)
M Schaumann Workshop on Ions at the FCC CERN
27
Smaller Z Ions ndash Impact on hadronic event count
20140922
bull Lower Z possibly higher available from injectors
bull Contribution of ultra-peripheral electromagnetic processes to the total cross-section would be reduced
Increased luminosity lifetime more particles available for hadronic interactions
Reduced secondary beam power emerging from collision point
bull Radiation damping rate does not change much for Zgt60o
o Lower Z beams would put more burn-off into hadronic events
o Worth considering small Z reduction from Pb to eg
(6--8)hadronic
BFPP EMD
hh tot
h
N Ldt N Z
Z
( )(Pb)L ZL
28
Heavy-Ion Beam Parameter Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
29
Heavy-Ion Luminosity Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
30
Future work neededbull Number of active experiments to be considered very carefully
1 or 2 bull Counter measures for (few kW) secondary beams from IPs
ndash Robust collimatorsabsorbers in dispersion suppressorsndash Shower calculations magnet quench risks etc
bull Include heavy ion beams in future evolution of injector chainndash Maximise no of ions injected in colliderndash Do we have to live with present limits in SPS
bull Extend LHC heavy-ion collimation studies to FCCndash Does synchrotron radiation damping solve this for us
bull Vacuum effects
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Collaboration welcome
31
Conclusions and Outlookbull With very conservative assumptions (past LHC Pb
beams) FCC-hh has clear potential for high luminosity nucleus-nucleus and proton-nucleus collisions
bull New highly efficient collider regime of strong radiation damping can be fully exploited with heavy-ion beams
bull Photon-photon and photonuclear processes create powerful secondary beams emerging from IPndash Foresee counter-measures from the start (cf LHC experience)
bull Extreme luminosity burn-off is a fact of nature ndash physics community might want to consider somewhat lower-Z species
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
32
BACKUP SLIDES
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
3
Problems that are ldquoin the shadowrdquo of p-pbull Optics designbull Collective effects
ndash lower charge per bunch fewer bunchesndash Including impedance-driven beam-beam electron cloud
bull Stored beam energyndash Not as large as in p-p (but still large hellip)ndash Nevertheless collimation efficiency is likely to be much
lower
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
4
What is new with heavy-ion beams wrt protonsbull Synchrotron radiation damping is twice as fast
ndash Free natural beam cooling not limited by beam-beam tune-shift
bull Pb nuclei are accompanied by intense fluxes of high energy quasi-real photonsndash (Physics interest hellip)ndash Leads to powerful secondary beams emerging from collision
pointndash Extreme luminosity burn-off from electromagnetic cross-
sectionsndash More complicated interactions with collimators
bull Stronger intra-beam scattering ultimately limits emittanceJM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
5
4 in the same magnetic fieldZm
5
Physics with ions at FCCbull Physics opportunities with heavy ion beams at the FCC (AA pA)
are investigated by a dedicated WG within the FCC-hh group 4 workshops held (httpsindicocernchevent331669 and links therein)
bull Main directionsndash Quark-Gluon Plasma studies
bull larger size and stronger expansion better sensitivity to QGP-fluid propertiesbull higher temperature large thermal charm production full melting of quarkoniabull new hard probes available (eg top quarks)
ndash Saturation of small-x gluon densities (with pA and eA) reach down xBjorken~10-6 (one order of magnitude smaller than at LHC)
ndash Ion beams photon-induced collisions (g+g g+A) saturation and EW studies
bull More informationndash Presentation on eA (and AA) physics by MPloskon (this workshop)ndash httparXiv14077649 ( Nuclear Physics A 931 2014 1163ndash1168 )ndash httpstwikicernchtwikibinviewLHCPhysicsHeavyIons
Slide from A DaineseJM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Just two examples
6
bull Significantly larger initial temperature Could reach close to 1 GeVndash Abundant ldquothermalrdquo production of c-
cbar pairs in the mediumndash Full suppression of quarkonia (Y(1S)
may not be suppressed at LHC)bull Anisotropic flow measurements
become sensitive to currently-inaccessible properties of the QGP eg temperature dependence of viscosity
Based on B-W Zhang et al PRC77 (2008)
dNcc
dy
50
3520
LHC FCC
G Denicol in httpsindicocernchevent331669 Slide from A DaineseJM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
7
Previous references on AA amp pA in FCC-hhbull M Schaumann Ions at the Future Hadron Collider 16-17 Dec
2013 CERN httpsindicocernchevent288576 bull M Schaumann FCC Study Kick-off Meeting 12-15 Feb 2014
Geneva httpsindicocernchevent282344bull M Schaumann Ions at the Future Hadron Collider
httpsindicocernchevent331669 (update to 100 km)
bull M Schaumann Chapter 9 of thesis submitted to RWTH Aachenbull M Schaumann ldquoPotential performance for Pb-Pb p-Pb and p-p
collisions in a future circular colliderrdquo paper submitted to Phys Rev ST-AB
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Studies focussed on emittance and luminosity evolution with strong radiation damping IBS and luminosity burn-off etc
8
CERN Heavy-Ion Injector Complexbull Present study very conservatively assumes the Pb
injector performance achieved for LHC p-Pb run in 2013
bull Potential upgrades needing studyndash Better ion source ndash Upgradereplacement of LEIR faster cooling higher injection
into PS ndash Degradation of bunches along trains at SPS injection
(alternatives to fixed harmonic acceleration with present200 MHz RF system)
bull LHC as HEB injector into FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Heavy Ion Pre-Accelerator Chain
9JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Straw-man assumption to estimate (conservative) beam parameters and luminosity LHC as it is today but cycling to 33 Z TeV is assumed to be the injector for FCC-hh
Present heavy-ion pre-injectors
LEIRHI source + LINAC 3
Baseline Inject one LHC beam into 14 FCC no waiting ramp immediately
PS
SPS
LHCFCC
10
Pb Beam Parameters in LHC and FCC-hh
LHCDesign
LHC 2011
LHC 2013
FCC-hh
Beam Energy [Z TeV] 7 35 4 50
β-function at the IP [m] 05 10 08 11
No Ions per bunch [] 07 14
Transv normalised emittance [] 15 15
RMS Beam Size at IP [] 159 339 266 88
RMS bunch length [] 794 8
Number of bunches 592 358 358 432
Peak Luminosity [] 1 (Pb-Pb) 110 (p-Pb)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Best injector performance achieved in 2013 p-Pb run
Average beam parameters from 2013 are assumed as VERY conservative baseline for FCC-hh
Improvements are already under study for HL-LHC
Geometric emittance at injection gt protons ndash possible issue for aperture choice
11
Beam and Luminosity Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
During the beams are in collision the instantaneous value of the luminosity will change
The beam evolution with time is obtained by solving a system of four differential equations (dominant effects only shown here more included in simulations)
with
revolution freq no bunchesbeam β-function at IP no particlesbunch geom emittances bunch length
total cross-section IBS growth rate rad damping rateIntensity
Hor Emittance
Ver Emittance
Bunch Length
Analytical solution difficult due to dependence of on
12
Effects on the Emittance ndash a new regime
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Intra-Beam Scattering (IBS) (Synchrotron) Radiation Damping
Emittance Growth Emittance Shrinkage
Growth rate dynamically changing with beam properties
Damping rate is constant for a given energy
IBS is weak for initial beam parameters but increases with decreasing emittance
Multiple small-angle Coulomb scattering within a charged particle beam
A charged particle radiates energy when itis accelerated ie bend on its circular orbit
Fast emittance decrease at the beginning of the fill until IBS becomes strong enough to counteract the radiation damping
Growth Times Unit FCC 50Z TeV
[h] 291
[h] 300
Damping Times Unit FCC 50Z TeV
[h] 024
[h] 049
13
BEAM AND LUMINOSITY EVOLUTION
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Pb-Pb
14
Pb-Pb Beam Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
bull Red tracking simulation taking into account IBS rad damping burn-off hellip
bull Black numerical solution of the ODE system on slide 7 using J Weirsquos analytical IBS formalism
rarr emittances and bunch length become very small
bull Green ddt = 0 artificial longitudinal blow-up to = 8cm
bull Blue artificial longitudinal and transverse blow-up to = 8cm and J Wei Evolution of Hadron Beams under Intrabeam
Scattering ConfProc C930517 (1993) 3651-3653 PAC 1993
Transverse Emittance
Bunch Length
Intensity
15
Pb-Pb Luminosity Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 0006 26
[Hzmb] 0017 73
[] 013 578
Summary for free beam evolution (no artificial blow-up)
If the beam dimensions become too small and artificial blow-up has to be used the luminosity will be affectedbull Peak Enhancement for long blow-up
since long and horizontal IBS are reduced due to larger rarr smaller
bull Reduced luminosity due to blown-up
16
Pb-Pb Average Luminosity
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
= time in collisions rarr to be optimised
= turn-around time = time dump rarr next collisions
Assumption (cycle time FCC without injections) (no injections from LHC)
Average Luminosity per hour
For free beam parameter evolution red case from previous slide
Max at
inst
17
Pb-Pb Integrated Luminosity per Run
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
bull Assumption
bull Consider more LHC injectionsrarr max (= FCC Length)rarr Dwell time at FCC inj plateau
rarr lengthen rarr Particle losses (amp emittance
growth)rarr Loss rate of Pb at injectionrarr Total beam intensity
rarr ltgt ltgt
Int Luminosity per run
Opt Time in Collisions
18
BEAM AND LUMINOSITY EVOLUTION
LHC has shown that p-Pb injecting and ramping with unequal revolution frequencies is feasible This will work for injection (provided we keep independent RF systems) and may not even be necessary in FCC ring
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
p-Pb
19
p-Pb Beam Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam Size Bunch Length
Intensity
Initial conditionsbull Pb-beam as for Pb-Pb operationbull Equal beam sizes σ for p and Pbbull Rad damping
rarr bull IBS scales with bull
rarr Fast Pb burn-off while const
20
p-Pb Luminosity Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 05 213
[Hzmb] 28 1192
[] 487 21068
Peak shifted to later timesrarr p shrinks slower than Pb
Luminosity decay slowerrarr constrarr 1e-Luminosity lifetime 14h
p-Pb Luminosity vs Turn-Around Time
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 201521
Max at
Int Luminosity per run
Opt Time in Collisions
For rarr Optimised fill length = 65h rarr ltgtrun 17 could give higher ltgtrun rarr But uncertainty on prediction
significantly enhanced rarr Early beam aborts and longer inj
times due to lost beams in the LHC reduce ltgtrun
rarr injection and fill times are both in the order of 10h
22
POTENTIAL LIMITATIONS
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
23
Beam-Beam Tune Shift
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam-Beam Parameter per Experiment
Unit LHC Designp-p
LHC DesignPb-Pb
FCCPb-Pb
FCCp-Pb
Initial [ 37 018 037 037
Peak [ 37 018 14 83
Beam-beam tune shift per experimentbull Beam m receives kick from Beam n bull uv =x y
The tune shift due to beam-beam interactions remains well below assumed limit for Pb-Pb but comes close to the limit for Pb in p-Pb collisions
Pb-Pb
p-Pb
γ-γ and γ-A processes in Pb-Pb collisions at FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015 24
2
208208 208
208208
20882 82 82
82 82 8
08208 82 208 82 82 20
20 20
8 8
8 2
8
0
1
7 82
B
BFPP2 Pb Pb Pb Pb 2e 10 mb
FPP1 Pb Pb Pb e 354 b 001235
EMD1 Pb Pb Pb n 20
00Pb
b
2
P
500
0
208208 82 8208 02 2 6 88 2 2
b 000485EMD2 Pb Pb P b 2n
35 b 000970Pb
Each of these makes a secondary beam emerging from the IP with rigidity change
Pb1 11 m mQ Q
Extensively discussed for LHC
Hadronic cross section is 8 b (so much less power in debris)
25
BFPP1 Beam Power in Pb-Pb for FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Countermeasures (eg DS collimators) have to be considered in initial lattice amp hardware design
FCC-PbPb
nominal LHC P 26Wrarr already expected to cause operational problems and poaaible long-term damage
41 PeV
BFPP1 Beam power 17 kW (peak)cP L E
26
Secondary beams from Pb-Pb collisions (Lattice V4 baseline)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
IP
208Pb81+ (BFPP1)208Pb80+ (BFPP2)
206Pb82+ (EMD2)
207Pb82+ (EMD1)
M Schaumann Workshop on Ions at the FCC CERN
27
Smaller Z Ions ndash Impact on hadronic event count
20140922
bull Lower Z possibly higher available from injectors
bull Contribution of ultra-peripheral electromagnetic processes to the total cross-section would be reduced
Increased luminosity lifetime more particles available for hadronic interactions
Reduced secondary beam power emerging from collision point
bull Radiation damping rate does not change much for Zgt60o
o Lower Z beams would put more burn-off into hadronic events
o Worth considering small Z reduction from Pb to eg
(6--8)hadronic
BFPP EMD
hh tot
h
N Ldt N Z
Z
( )(Pb)L ZL
28
Heavy-Ion Beam Parameter Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
29
Heavy-Ion Luminosity Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
30
Future work neededbull Number of active experiments to be considered very carefully
1 or 2 bull Counter measures for (few kW) secondary beams from IPs
ndash Robust collimatorsabsorbers in dispersion suppressorsndash Shower calculations magnet quench risks etc
bull Include heavy ion beams in future evolution of injector chainndash Maximise no of ions injected in colliderndash Do we have to live with present limits in SPS
bull Extend LHC heavy-ion collimation studies to FCCndash Does synchrotron radiation damping solve this for us
bull Vacuum effects
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Collaboration welcome
31
Conclusions and Outlookbull With very conservative assumptions (past LHC Pb
beams) FCC-hh has clear potential for high luminosity nucleus-nucleus and proton-nucleus collisions
bull New highly efficient collider regime of strong radiation damping can be fully exploited with heavy-ion beams
bull Photon-photon and photonuclear processes create powerful secondary beams emerging from IPndash Foresee counter-measures from the start (cf LHC experience)
bull Extreme luminosity burn-off is a fact of nature ndash physics community might want to consider somewhat lower-Z species
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
32
BACKUP SLIDES
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
4
What is new with heavy-ion beams wrt protonsbull Synchrotron radiation damping is twice as fast
ndash Free natural beam cooling not limited by beam-beam tune-shift
bull Pb nuclei are accompanied by intense fluxes of high energy quasi-real photonsndash (Physics interest hellip)ndash Leads to powerful secondary beams emerging from collision
pointndash Extreme luminosity burn-off from electromagnetic cross-
sectionsndash More complicated interactions with collimators
bull Stronger intra-beam scattering ultimately limits emittanceJM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
5
4 in the same magnetic fieldZm
5
Physics with ions at FCCbull Physics opportunities with heavy ion beams at the FCC (AA pA)
are investigated by a dedicated WG within the FCC-hh group 4 workshops held (httpsindicocernchevent331669 and links therein)
bull Main directionsndash Quark-Gluon Plasma studies
bull larger size and stronger expansion better sensitivity to QGP-fluid propertiesbull higher temperature large thermal charm production full melting of quarkoniabull new hard probes available (eg top quarks)
ndash Saturation of small-x gluon densities (with pA and eA) reach down xBjorken~10-6 (one order of magnitude smaller than at LHC)
ndash Ion beams photon-induced collisions (g+g g+A) saturation and EW studies
bull More informationndash Presentation on eA (and AA) physics by MPloskon (this workshop)ndash httparXiv14077649 ( Nuclear Physics A 931 2014 1163ndash1168 )ndash httpstwikicernchtwikibinviewLHCPhysicsHeavyIons
Slide from A DaineseJM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Just two examples
6
bull Significantly larger initial temperature Could reach close to 1 GeVndash Abundant ldquothermalrdquo production of c-
cbar pairs in the mediumndash Full suppression of quarkonia (Y(1S)
may not be suppressed at LHC)bull Anisotropic flow measurements
become sensitive to currently-inaccessible properties of the QGP eg temperature dependence of viscosity
Based on B-W Zhang et al PRC77 (2008)
dNcc
dy
50
3520
LHC FCC
G Denicol in httpsindicocernchevent331669 Slide from A DaineseJM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
7
Previous references on AA amp pA in FCC-hhbull M Schaumann Ions at the Future Hadron Collider 16-17 Dec
2013 CERN httpsindicocernchevent288576 bull M Schaumann FCC Study Kick-off Meeting 12-15 Feb 2014
Geneva httpsindicocernchevent282344bull M Schaumann Ions at the Future Hadron Collider
httpsindicocernchevent331669 (update to 100 km)
bull M Schaumann Chapter 9 of thesis submitted to RWTH Aachenbull M Schaumann ldquoPotential performance for Pb-Pb p-Pb and p-p
collisions in a future circular colliderrdquo paper submitted to Phys Rev ST-AB
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Studies focussed on emittance and luminosity evolution with strong radiation damping IBS and luminosity burn-off etc
8
CERN Heavy-Ion Injector Complexbull Present study very conservatively assumes the Pb
injector performance achieved for LHC p-Pb run in 2013
bull Potential upgrades needing studyndash Better ion source ndash Upgradereplacement of LEIR faster cooling higher injection
into PS ndash Degradation of bunches along trains at SPS injection
(alternatives to fixed harmonic acceleration with present200 MHz RF system)
bull LHC as HEB injector into FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Heavy Ion Pre-Accelerator Chain
9JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Straw-man assumption to estimate (conservative) beam parameters and luminosity LHC as it is today but cycling to 33 Z TeV is assumed to be the injector for FCC-hh
Present heavy-ion pre-injectors
LEIRHI source + LINAC 3
Baseline Inject one LHC beam into 14 FCC no waiting ramp immediately
PS
SPS
LHCFCC
10
Pb Beam Parameters in LHC and FCC-hh
LHCDesign
LHC 2011
LHC 2013
FCC-hh
Beam Energy [Z TeV] 7 35 4 50
β-function at the IP [m] 05 10 08 11
No Ions per bunch [] 07 14
Transv normalised emittance [] 15 15
RMS Beam Size at IP [] 159 339 266 88
RMS bunch length [] 794 8
Number of bunches 592 358 358 432
Peak Luminosity [] 1 (Pb-Pb) 110 (p-Pb)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Best injector performance achieved in 2013 p-Pb run
Average beam parameters from 2013 are assumed as VERY conservative baseline for FCC-hh
Improvements are already under study for HL-LHC
Geometric emittance at injection gt protons ndash possible issue for aperture choice
11
Beam and Luminosity Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
During the beams are in collision the instantaneous value of the luminosity will change
The beam evolution with time is obtained by solving a system of four differential equations (dominant effects only shown here more included in simulations)
with
revolution freq no bunchesbeam β-function at IP no particlesbunch geom emittances bunch length
total cross-section IBS growth rate rad damping rateIntensity
Hor Emittance
Ver Emittance
Bunch Length
Analytical solution difficult due to dependence of on
12
Effects on the Emittance ndash a new regime
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Intra-Beam Scattering (IBS) (Synchrotron) Radiation Damping
Emittance Growth Emittance Shrinkage
Growth rate dynamically changing with beam properties
Damping rate is constant for a given energy
IBS is weak for initial beam parameters but increases with decreasing emittance
Multiple small-angle Coulomb scattering within a charged particle beam
A charged particle radiates energy when itis accelerated ie bend on its circular orbit
Fast emittance decrease at the beginning of the fill until IBS becomes strong enough to counteract the radiation damping
Growth Times Unit FCC 50Z TeV
[h] 291
[h] 300
Damping Times Unit FCC 50Z TeV
[h] 024
[h] 049
13
BEAM AND LUMINOSITY EVOLUTION
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Pb-Pb
14
Pb-Pb Beam Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
bull Red tracking simulation taking into account IBS rad damping burn-off hellip
bull Black numerical solution of the ODE system on slide 7 using J Weirsquos analytical IBS formalism
rarr emittances and bunch length become very small
bull Green ddt = 0 artificial longitudinal blow-up to = 8cm
bull Blue artificial longitudinal and transverse blow-up to = 8cm and J Wei Evolution of Hadron Beams under Intrabeam
Scattering ConfProc C930517 (1993) 3651-3653 PAC 1993
Transverse Emittance
Bunch Length
Intensity
15
Pb-Pb Luminosity Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 0006 26
[Hzmb] 0017 73
[] 013 578
Summary for free beam evolution (no artificial blow-up)
If the beam dimensions become too small and artificial blow-up has to be used the luminosity will be affectedbull Peak Enhancement for long blow-up
since long and horizontal IBS are reduced due to larger rarr smaller
bull Reduced luminosity due to blown-up
16
Pb-Pb Average Luminosity
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
= time in collisions rarr to be optimised
= turn-around time = time dump rarr next collisions
Assumption (cycle time FCC without injections) (no injections from LHC)
Average Luminosity per hour
For free beam parameter evolution red case from previous slide
Max at
inst
17
Pb-Pb Integrated Luminosity per Run
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
bull Assumption
bull Consider more LHC injectionsrarr max (= FCC Length)rarr Dwell time at FCC inj plateau
rarr lengthen rarr Particle losses (amp emittance
growth)rarr Loss rate of Pb at injectionrarr Total beam intensity
rarr ltgt ltgt
Int Luminosity per run
Opt Time in Collisions
18
BEAM AND LUMINOSITY EVOLUTION
LHC has shown that p-Pb injecting and ramping with unequal revolution frequencies is feasible This will work for injection (provided we keep independent RF systems) and may not even be necessary in FCC ring
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
p-Pb
19
p-Pb Beam Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam Size Bunch Length
Intensity
Initial conditionsbull Pb-beam as for Pb-Pb operationbull Equal beam sizes σ for p and Pbbull Rad damping
rarr bull IBS scales with bull
rarr Fast Pb burn-off while const
20
p-Pb Luminosity Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 05 213
[Hzmb] 28 1192
[] 487 21068
Peak shifted to later timesrarr p shrinks slower than Pb
Luminosity decay slowerrarr constrarr 1e-Luminosity lifetime 14h
p-Pb Luminosity vs Turn-Around Time
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 201521
Max at
Int Luminosity per run
Opt Time in Collisions
For rarr Optimised fill length = 65h rarr ltgtrun 17 could give higher ltgtrun rarr But uncertainty on prediction
significantly enhanced rarr Early beam aborts and longer inj
times due to lost beams in the LHC reduce ltgtrun
rarr injection and fill times are both in the order of 10h
22
POTENTIAL LIMITATIONS
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
23
Beam-Beam Tune Shift
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam-Beam Parameter per Experiment
Unit LHC Designp-p
LHC DesignPb-Pb
FCCPb-Pb
FCCp-Pb
Initial [ 37 018 037 037
Peak [ 37 018 14 83
Beam-beam tune shift per experimentbull Beam m receives kick from Beam n bull uv =x y
The tune shift due to beam-beam interactions remains well below assumed limit for Pb-Pb but comes close to the limit for Pb in p-Pb collisions
Pb-Pb
p-Pb
γ-γ and γ-A processes in Pb-Pb collisions at FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015 24
2
208208 208
208208
20882 82 82
82 82 8
08208 82 208 82 82 20
20 20
8 8
8 2
8
0
1
7 82
B
BFPP2 Pb Pb Pb Pb 2e 10 mb
FPP1 Pb Pb Pb e 354 b 001235
EMD1 Pb Pb Pb n 20
00Pb
b
2
P
500
0
208208 82 8208 02 2 6 88 2 2
b 000485EMD2 Pb Pb P b 2n
35 b 000970Pb
Each of these makes a secondary beam emerging from the IP with rigidity change
Pb1 11 m mQ Q
Extensively discussed for LHC
Hadronic cross section is 8 b (so much less power in debris)
25
BFPP1 Beam Power in Pb-Pb for FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Countermeasures (eg DS collimators) have to be considered in initial lattice amp hardware design
FCC-PbPb
nominal LHC P 26Wrarr already expected to cause operational problems and poaaible long-term damage
41 PeV
BFPP1 Beam power 17 kW (peak)cP L E
26
Secondary beams from Pb-Pb collisions (Lattice V4 baseline)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
IP
208Pb81+ (BFPP1)208Pb80+ (BFPP2)
206Pb82+ (EMD2)
207Pb82+ (EMD1)
M Schaumann Workshop on Ions at the FCC CERN
27
Smaller Z Ions ndash Impact on hadronic event count
20140922
bull Lower Z possibly higher available from injectors
bull Contribution of ultra-peripheral electromagnetic processes to the total cross-section would be reduced
Increased luminosity lifetime more particles available for hadronic interactions
Reduced secondary beam power emerging from collision point
bull Radiation damping rate does not change much for Zgt60o
o Lower Z beams would put more burn-off into hadronic events
o Worth considering small Z reduction from Pb to eg
(6--8)hadronic
BFPP EMD
hh tot
h
N Ldt N Z
Z
( )(Pb)L ZL
28
Heavy-Ion Beam Parameter Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
29
Heavy-Ion Luminosity Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
30
Future work neededbull Number of active experiments to be considered very carefully
1 or 2 bull Counter measures for (few kW) secondary beams from IPs
ndash Robust collimatorsabsorbers in dispersion suppressorsndash Shower calculations magnet quench risks etc
bull Include heavy ion beams in future evolution of injector chainndash Maximise no of ions injected in colliderndash Do we have to live with present limits in SPS
bull Extend LHC heavy-ion collimation studies to FCCndash Does synchrotron radiation damping solve this for us
bull Vacuum effects
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Collaboration welcome
31
Conclusions and Outlookbull With very conservative assumptions (past LHC Pb
beams) FCC-hh has clear potential for high luminosity nucleus-nucleus and proton-nucleus collisions
bull New highly efficient collider regime of strong radiation damping can be fully exploited with heavy-ion beams
bull Photon-photon and photonuclear processes create powerful secondary beams emerging from IPndash Foresee counter-measures from the start (cf LHC experience)
bull Extreme luminosity burn-off is a fact of nature ndash physics community might want to consider somewhat lower-Z species
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
32
BACKUP SLIDES
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
5
Physics with ions at FCCbull Physics opportunities with heavy ion beams at the FCC (AA pA)
are investigated by a dedicated WG within the FCC-hh group 4 workshops held (httpsindicocernchevent331669 and links therein)
bull Main directionsndash Quark-Gluon Plasma studies
bull larger size and stronger expansion better sensitivity to QGP-fluid propertiesbull higher temperature large thermal charm production full melting of quarkoniabull new hard probes available (eg top quarks)
ndash Saturation of small-x gluon densities (with pA and eA) reach down xBjorken~10-6 (one order of magnitude smaller than at LHC)
ndash Ion beams photon-induced collisions (g+g g+A) saturation and EW studies
bull More informationndash Presentation on eA (and AA) physics by MPloskon (this workshop)ndash httparXiv14077649 ( Nuclear Physics A 931 2014 1163ndash1168 )ndash httpstwikicernchtwikibinviewLHCPhysicsHeavyIons
Slide from A DaineseJM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Just two examples
6
bull Significantly larger initial temperature Could reach close to 1 GeVndash Abundant ldquothermalrdquo production of c-
cbar pairs in the mediumndash Full suppression of quarkonia (Y(1S)
may not be suppressed at LHC)bull Anisotropic flow measurements
become sensitive to currently-inaccessible properties of the QGP eg temperature dependence of viscosity
Based on B-W Zhang et al PRC77 (2008)
dNcc
dy
50
3520
LHC FCC
G Denicol in httpsindicocernchevent331669 Slide from A DaineseJM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
7
Previous references on AA amp pA in FCC-hhbull M Schaumann Ions at the Future Hadron Collider 16-17 Dec
2013 CERN httpsindicocernchevent288576 bull M Schaumann FCC Study Kick-off Meeting 12-15 Feb 2014
Geneva httpsindicocernchevent282344bull M Schaumann Ions at the Future Hadron Collider
httpsindicocernchevent331669 (update to 100 km)
bull M Schaumann Chapter 9 of thesis submitted to RWTH Aachenbull M Schaumann ldquoPotential performance for Pb-Pb p-Pb and p-p
collisions in a future circular colliderrdquo paper submitted to Phys Rev ST-AB
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Studies focussed on emittance and luminosity evolution with strong radiation damping IBS and luminosity burn-off etc
8
CERN Heavy-Ion Injector Complexbull Present study very conservatively assumes the Pb
injector performance achieved for LHC p-Pb run in 2013
bull Potential upgrades needing studyndash Better ion source ndash Upgradereplacement of LEIR faster cooling higher injection
into PS ndash Degradation of bunches along trains at SPS injection
(alternatives to fixed harmonic acceleration with present200 MHz RF system)
bull LHC as HEB injector into FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Heavy Ion Pre-Accelerator Chain
9JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Straw-man assumption to estimate (conservative) beam parameters and luminosity LHC as it is today but cycling to 33 Z TeV is assumed to be the injector for FCC-hh
Present heavy-ion pre-injectors
LEIRHI source + LINAC 3
Baseline Inject one LHC beam into 14 FCC no waiting ramp immediately
PS
SPS
LHCFCC
10
Pb Beam Parameters in LHC and FCC-hh
LHCDesign
LHC 2011
LHC 2013
FCC-hh
Beam Energy [Z TeV] 7 35 4 50
β-function at the IP [m] 05 10 08 11
No Ions per bunch [] 07 14
Transv normalised emittance [] 15 15
RMS Beam Size at IP [] 159 339 266 88
RMS bunch length [] 794 8
Number of bunches 592 358 358 432
Peak Luminosity [] 1 (Pb-Pb) 110 (p-Pb)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Best injector performance achieved in 2013 p-Pb run
Average beam parameters from 2013 are assumed as VERY conservative baseline for FCC-hh
Improvements are already under study for HL-LHC
Geometric emittance at injection gt protons ndash possible issue for aperture choice
11
Beam and Luminosity Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
During the beams are in collision the instantaneous value of the luminosity will change
The beam evolution with time is obtained by solving a system of four differential equations (dominant effects only shown here more included in simulations)
with
revolution freq no bunchesbeam β-function at IP no particlesbunch geom emittances bunch length
total cross-section IBS growth rate rad damping rateIntensity
Hor Emittance
Ver Emittance
Bunch Length
Analytical solution difficult due to dependence of on
12
Effects on the Emittance ndash a new regime
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Intra-Beam Scattering (IBS) (Synchrotron) Radiation Damping
Emittance Growth Emittance Shrinkage
Growth rate dynamically changing with beam properties
Damping rate is constant for a given energy
IBS is weak for initial beam parameters but increases with decreasing emittance
Multiple small-angle Coulomb scattering within a charged particle beam
A charged particle radiates energy when itis accelerated ie bend on its circular orbit
Fast emittance decrease at the beginning of the fill until IBS becomes strong enough to counteract the radiation damping
Growth Times Unit FCC 50Z TeV
[h] 291
[h] 300
Damping Times Unit FCC 50Z TeV
[h] 024
[h] 049
13
BEAM AND LUMINOSITY EVOLUTION
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Pb-Pb
14
Pb-Pb Beam Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
bull Red tracking simulation taking into account IBS rad damping burn-off hellip
bull Black numerical solution of the ODE system on slide 7 using J Weirsquos analytical IBS formalism
rarr emittances and bunch length become very small
bull Green ddt = 0 artificial longitudinal blow-up to = 8cm
bull Blue artificial longitudinal and transverse blow-up to = 8cm and J Wei Evolution of Hadron Beams under Intrabeam
Scattering ConfProc C930517 (1993) 3651-3653 PAC 1993
Transverse Emittance
Bunch Length
Intensity
15
Pb-Pb Luminosity Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 0006 26
[Hzmb] 0017 73
[] 013 578
Summary for free beam evolution (no artificial blow-up)
If the beam dimensions become too small and artificial blow-up has to be used the luminosity will be affectedbull Peak Enhancement for long blow-up
since long and horizontal IBS are reduced due to larger rarr smaller
bull Reduced luminosity due to blown-up
16
Pb-Pb Average Luminosity
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
= time in collisions rarr to be optimised
= turn-around time = time dump rarr next collisions
Assumption (cycle time FCC without injections) (no injections from LHC)
Average Luminosity per hour
For free beam parameter evolution red case from previous slide
Max at
inst
17
Pb-Pb Integrated Luminosity per Run
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
bull Assumption
bull Consider more LHC injectionsrarr max (= FCC Length)rarr Dwell time at FCC inj plateau
rarr lengthen rarr Particle losses (amp emittance
growth)rarr Loss rate of Pb at injectionrarr Total beam intensity
rarr ltgt ltgt
Int Luminosity per run
Opt Time in Collisions
18
BEAM AND LUMINOSITY EVOLUTION
LHC has shown that p-Pb injecting and ramping with unequal revolution frequencies is feasible This will work for injection (provided we keep independent RF systems) and may not even be necessary in FCC ring
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
p-Pb
19
p-Pb Beam Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam Size Bunch Length
Intensity
Initial conditionsbull Pb-beam as for Pb-Pb operationbull Equal beam sizes σ for p and Pbbull Rad damping
rarr bull IBS scales with bull
rarr Fast Pb burn-off while const
20
p-Pb Luminosity Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 05 213
[Hzmb] 28 1192
[] 487 21068
Peak shifted to later timesrarr p shrinks slower than Pb
Luminosity decay slowerrarr constrarr 1e-Luminosity lifetime 14h
p-Pb Luminosity vs Turn-Around Time
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 201521
Max at
Int Luminosity per run
Opt Time in Collisions
For rarr Optimised fill length = 65h rarr ltgtrun 17 could give higher ltgtrun rarr But uncertainty on prediction
significantly enhanced rarr Early beam aborts and longer inj
times due to lost beams in the LHC reduce ltgtrun
rarr injection and fill times are both in the order of 10h
22
POTENTIAL LIMITATIONS
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
23
Beam-Beam Tune Shift
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam-Beam Parameter per Experiment
Unit LHC Designp-p
LHC DesignPb-Pb
FCCPb-Pb
FCCp-Pb
Initial [ 37 018 037 037
Peak [ 37 018 14 83
Beam-beam tune shift per experimentbull Beam m receives kick from Beam n bull uv =x y
The tune shift due to beam-beam interactions remains well below assumed limit for Pb-Pb but comes close to the limit for Pb in p-Pb collisions
Pb-Pb
p-Pb
γ-γ and γ-A processes in Pb-Pb collisions at FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015 24
2
208208 208
208208
20882 82 82
82 82 8
08208 82 208 82 82 20
20 20
8 8
8 2
8
0
1
7 82
B
BFPP2 Pb Pb Pb Pb 2e 10 mb
FPP1 Pb Pb Pb e 354 b 001235
EMD1 Pb Pb Pb n 20
00Pb
b
2
P
500
0
208208 82 8208 02 2 6 88 2 2
b 000485EMD2 Pb Pb P b 2n
35 b 000970Pb
Each of these makes a secondary beam emerging from the IP with rigidity change
Pb1 11 m mQ Q
Extensively discussed for LHC
Hadronic cross section is 8 b (so much less power in debris)
25
BFPP1 Beam Power in Pb-Pb for FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Countermeasures (eg DS collimators) have to be considered in initial lattice amp hardware design
FCC-PbPb
nominal LHC P 26Wrarr already expected to cause operational problems and poaaible long-term damage
41 PeV
BFPP1 Beam power 17 kW (peak)cP L E
26
Secondary beams from Pb-Pb collisions (Lattice V4 baseline)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
IP
208Pb81+ (BFPP1)208Pb80+ (BFPP2)
206Pb82+ (EMD2)
207Pb82+ (EMD1)
M Schaumann Workshop on Ions at the FCC CERN
27
Smaller Z Ions ndash Impact on hadronic event count
20140922
bull Lower Z possibly higher available from injectors
bull Contribution of ultra-peripheral electromagnetic processes to the total cross-section would be reduced
Increased luminosity lifetime more particles available for hadronic interactions
Reduced secondary beam power emerging from collision point
bull Radiation damping rate does not change much for Zgt60o
o Lower Z beams would put more burn-off into hadronic events
o Worth considering small Z reduction from Pb to eg
(6--8)hadronic
BFPP EMD
hh tot
h
N Ldt N Z
Z
( )(Pb)L ZL
28
Heavy-Ion Beam Parameter Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
29
Heavy-Ion Luminosity Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
30
Future work neededbull Number of active experiments to be considered very carefully
1 or 2 bull Counter measures for (few kW) secondary beams from IPs
ndash Robust collimatorsabsorbers in dispersion suppressorsndash Shower calculations magnet quench risks etc
bull Include heavy ion beams in future evolution of injector chainndash Maximise no of ions injected in colliderndash Do we have to live with present limits in SPS
bull Extend LHC heavy-ion collimation studies to FCCndash Does synchrotron radiation damping solve this for us
bull Vacuum effects
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Collaboration welcome
31
Conclusions and Outlookbull With very conservative assumptions (past LHC Pb
beams) FCC-hh has clear potential for high luminosity nucleus-nucleus and proton-nucleus collisions
bull New highly efficient collider regime of strong radiation damping can be fully exploited with heavy-ion beams
bull Photon-photon and photonuclear processes create powerful secondary beams emerging from IPndash Foresee counter-measures from the start (cf LHC experience)
bull Extreme luminosity burn-off is a fact of nature ndash physics community might want to consider somewhat lower-Z species
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
32
BACKUP SLIDES
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Just two examples
6
bull Significantly larger initial temperature Could reach close to 1 GeVndash Abundant ldquothermalrdquo production of c-
cbar pairs in the mediumndash Full suppression of quarkonia (Y(1S)
may not be suppressed at LHC)bull Anisotropic flow measurements
become sensitive to currently-inaccessible properties of the QGP eg temperature dependence of viscosity
Based on B-W Zhang et al PRC77 (2008)
dNcc
dy
50
3520
LHC FCC
G Denicol in httpsindicocernchevent331669 Slide from A DaineseJM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
7
Previous references on AA amp pA in FCC-hhbull M Schaumann Ions at the Future Hadron Collider 16-17 Dec
2013 CERN httpsindicocernchevent288576 bull M Schaumann FCC Study Kick-off Meeting 12-15 Feb 2014
Geneva httpsindicocernchevent282344bull M Schaumann Ions at the Future Hadron Collider
httpsindicocernchevent331669 (update to 100 km)
bull M Schaumann Chapter 9 of thesis submitted to RWTH Aachenbull M Schaumann ldquoPotential performance for Pb-Pb p-Pb and p-p
collisions in a future circular colliderrdquo paper submitted to Phys Rev ST-AB
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Studies focussed on emittance and luminosity evolution with strong radiation damping IBS and luminosity burn-off etc
8
CERN Heavy-Ion Injector Complexbull Present study very conservatively assumes the Pb
injector performance achieved for LHC p-Pb run in 2013
bull Potential upgrades needing studyndash Better ion source ndash Upgradereplacement of LEIR faster cooling higher injection
into PS ndash Degradation of bunches along trains at SPS injection
(alternatives to fixed harmonic acceleration with present200 MHz RF system)
bull LHC as HEB injector into FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Heavy Ion Pre-Accelerator Chain
9JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Straw-man assumption to estimate (conservative) beam parameters and luminosity LHC as it is today but cycling to 33 Z TeV is assumed to be the injector for FCC-hh
Present heavy-ion pre-injectors
LEIRHI source + LINAC 3
Baseline Inject one LHC beam into 14 FCC no waiting ramp immediately
PS
SPS
LHCFCC
10
Pb Beam Parameters in LHC and FCC-hh
LHCDesign
LHC 2011
LHC 2013
FCC-hh
Beam Energy [Z TeV] 7 35 4 50
β-function at the IP [m] 05 10 08 11
No Ions per bunch [] 07 14
Transv normalised emittance [] 15 15
RMS Beam Size at IP [] 159 339 266 88
RMS bunch length [] 794 8
Number of bunches 592 358 358 432
Peak Luminosity [] 1 (Pb-Pb) 110 (p-Pb)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Best injector performance achieved in 2013 p-Pb run
Average beam parameters from 2013 are assumed as VERY conservative baseline for FCC-hh
Improvements are already under study for HL-LHC
Geometric emittance at injection gt protons ndash possible issue for aperture choice
11
Beam and Luminosity Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
During the beams are in collision the instantaneous value of the luminosity will change
The beam evolution with time is obtained by solving a system of four differential equations (dominant effects only shown here more included in simulations)
with
revolution freq no bunchesbeam β-function at IP no particlesbunch geom emittances bunch length
total cross-section IBS growth rate rad damping rateIntensity
Hor Emittance
Ver Emittance
Bunch Length
Analytical solution difficult due to dependence of on
12
Effects on the Emittance ndash a new regime
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Intra-Beam Scattering (IBS) (Synchrotron) Radiation Damping
Emittance Growth Emittance Shrinkage
Growth rate dynamically changing with beam properties
Damping rate is constant for a given energy
IBS is weak for initial beam parameters but increases with decreasing emittance
Multiple small-angle Coulomb scattering within a charged particle beam
A charged particle radiates energy when itis accelerated ie bend on its circular orbit
Fast emittance decrease at the beginning of the fill until IBS becomes strong enough to counteract the radiation damping
Growth Times Unit FCC 50Z TeV
[h] 291
[h] 300
Damping Times Unit FCC 50Z TeV
[h] 024
[h] 049
13
BEAM AND LUMINOSITY EVOLUTION
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Pb-Pb
14
Pb-Pb Beam Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
bull Red tracking simulation taking into account IBS rad damping burn-off hellip
bull Black numerical solution of the ODE system on slide 7 using J Weirsquos analytical IBS formalism
rarr emittances and bunch length become very small
bull Green ddt = 0 artificial longitudinal blow-up to = 8cm
bull Blue artificial longitudinal and transverse blow-up to = 8cm and J Wei Evolution of Hadron Beams under Intrabeam
Scattering ConfProc C930517 (1993) 3651-3653 PAC 1993
Transverse Emittance
Bunch Length
Intensity
15
Pb-Pb Luminosity Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 0006 26
[Hzmb] 0017 73
[] 013 578
Summary for free beam evolution (no artificial blow-up)
If the beam dimensions become too small and artificial blow-up has to be used the luminosity will be affectedbull Peak Enhancement for long blow-up
since long and horizontal IBS are reduced due to larger rarr smaller
bull Reduced luminosity due to blown-up
16
Pb-Pb Average Luminosity
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
= time in collisions rarr to be optimised
= turn-around time = time dump rarr next collisions
Assumption (cycle time FCC without injections) (no injections from LHC)
Average Luminosity per hour
For free beam parameter evolution red case from previous slide
Max at
inst
17
Pb-Pb Integrated Luminosity per Run
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
bull Assumption
bull Consider more LHC injectionsrarr max (= FCC Length)rarr Dwell time at FCC inj plateau
rarr lengthen rarr Particle losses (amp emittance
growth)rarr Loss rate of Pb at injectionrarr Total beam intensity
rarr ltgt ltgt
Int Luminosity per run
Opt Time in Collisions
18
BEAM AND LUMINOSITY EVOLUTION
LHC has shown that p-Pb injecting and ramping with unequal revolution frequencies is feasible This will work for injection (provided we keep independent RF systems) and may not even be necessary in FCC ring
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
p-Pb
19
p-Pb Beam Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam Size Bunch Length
Intensity
Initial conditionsbull Pb-beam as for Pb-Pb operationbull Equal beam sizes σ for p and Pbbull Rad damping
rarr bull IBS scales with bull
rarr Fast Pb burn-off while const
20
p-Pb Luminosity Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 05 213
[Hzmb] 28 1192
[] 487 21068
Peak shifted to later timesrarr p shrinks slower than Pb
Luminosity decay slowerrarr constrarr 1e-Luminosity lifetime 14h
p-Pb Luminosity vs Turn-Around Time
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 201521
Max at
Int Luminosity per run
Opt Time in Collisions
For rarr Optimised fill length = 65h rarr ltgtrun 17 could give higher ltgtrun rarr But uncertainty on prediction
significantly enhanced rarr Early beam aborts and longer inj
times due to lost beams in the LHC reduce ltgtrun
rarr injection and fill times are both in the order of 10h
22
POTENTIAL LIMITATIONS
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
23
Beam-Beam Tune Shift
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam-Beam Parameter per Experiment
Unit LHC Designp-p
LHC DesignPb-Pb
FCCPb-Pb
FCCp-Pb
Initial [ 37 018 037 037
Peak [ 37 018 14 83
Beam-beam tune shift per experimentbull Beam m receives kick from Beam n bull uv =x y
The tune shift due to beam-beam interactions remains well below assumed limit for Pb-Pb but comes close to the limit for Pb in p-Pb collisions
Pb-Pb
p-Pb
γ-γ and γ-A processes in Pb-Pb collisions at FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015 24
2
208208 208
208208
20882 82 82
82 82 8
08208 82 208 82 82 20
20 20
8 8
8 2
8
0
1
7 82
B
BFPP2 Pb Pb Pb Pb 2e 10 mb
FPP1 Pb Pb Pb e 354 b 001235
EMD1 Pb Pb Pb n 20
00Pb
b
2
P
500
0
208208 82 8208 02 2 6 88 2 2
b 000485EMD2 Pb Pb P b 2n
35 b 000970Pb
Each of these makes a secondary beam emerging from the IP with rigidity change
Pb1 11 m mQ Q
Extensively discussed for LHC
Hadronic cross section is 8 b (so much less power in debris)
25
BFPP1 Beam Power in Pb-Pb for FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Countermeasures (eg DS collimators) have to be considered in initial lattice amp hardware design
FCC-PbPb
nominal LHC P 26Wrarr already expected to cause operational problems and poaaible long-term damage
41 PeV
BFPP1 Beam power 17 kW (peak)cP L E
26
Secondary beams from Pb-Pb collisions (Lattice V4 baseline)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
IP
208Pb81+ (BFPP1)208Pb80+ (BFPP2)
206Pb82+ (EMD2)
207Pb82+ (EMD1)
M Schaumann Workshop on Ions at the FCC CERN
27
Smaller Z Ions ndash Impact on hadronic event count
20140922
bull Lower Z possibly higher available from injectors
bull Contribution of ultra-peripheral electromagnetic processes to the total cross-section would be reduced
Increased luminosity lifetime more particles available for hadronic interactions
Reduced secondary beam power emerging from collision point
bull Radiation damping rate does not change much for Zgt60o
o Lower Z beams would put more burn-off into hadronic events
o Worth considering small Z reduction from Pb to eg
(6--8)hadronic
BFPP EMD
hh tot
h
N Ldt N Z
Z
( )(Pb)L ZL
28
Heavy-Ion Beam Parameter Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
29
Heavy-Ion Luminosity Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
30
Future work neededbull Number of active experiments to be considered very carefully
1 or 2 bull Counter measures for (few kW) secondary beams from IPs
ndash Robust collimatorsabsorbers in dispersion suppressorsndash Shower calculations magnet quench risks etc
bull Include heavy ion beams in future evolution of injector chainndash Maximise no of ions injected in colliderndash Do we have to live with present limits in SPS
bull Extend LHC heavy-ion collimation studies to FCCndash Does synchrotron radiation damping solve this for us
bull Vacuum effects
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Collaboration welcome
31
Conclusions and Outlookbull With very conservative assumptions (past LHC Pb
beams) FCC-hh has clear potential for high luminosity nucleus-nucleus and proton-nucleus collisions
bull New highly efficient collider regime of strong radiation damping can be fully exploited with heavy-ion beams
bull Photon-photon and photonuclear processes create powerful secondary beams emerging from IPndash Foresee counter-measures from the start (cf LHC experience)
bull Extreme luminosity burn-off is a fact of nature ndash physics community might want to consider somewhat lower-Z species
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
32
BACKUP SLIDES
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
7
Previous references on AA amp pA in FCC-hhbull M Schaumann Ions at the Future Hadron Collider 16-17 Dec
2013 CERN httpsindicocernchevent288576 bull M Schaumann FCC Study Kick-off Meeting 12-15 Feb 2014
Geneva httpsindicocernchevent282344bull M Schaumann Ions at the Future Hadron Collider
httpsindicocernchevent331669 (update to 100 km)
bull M Schaumann Chapter 9 of thesis submitted to RWTH Aachenbull M Schaumann ldquoPotential performance for Pb-Pb p-Pb and p-p
collisions in a future circular colliderrdquo paper submitted to Phys Rev ST-AB
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Studies focussed on emittance and luminosity evolution with strong radiation damping IBS and luminosity burn-off etc
8
CERN Heavy-Ion Injector Complexbull Present study very conservatively assumes the Pb
injector performance achieved for LHC p-Pb run in 2013
bull Potential upgrades needing studyndash Better ion source ndash Upgradereplacement of LEIR faster cooling higher injection
into PS ndash Degradation of bunches along trains at SPS injection
(alternatives to fixed harmonic acceleration with present200 MHz RF system)
bull LHC as HEB injector into FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Heavy Ion Pre-Accelerator Chain
9JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Straw-man assumption to estimate (conservative) beam parameters and luminosity LHC as it is today but cycling to 33 Z TeV is assumed to be the injector for FCC-hh
Present heavy-ion pre-injectors
LEIRHI source + LINAC 3
Baseline Inject one LHC beam into 14 FCC no waiting ramp immediately
PS
SPS
LHCFCC
10
Pb Beam Parameters in LHC and FCC-hh
LHCDesign
LHC 2011
LHC 2013
FCC-hh
Beam Energy [Z TeV] 7 35 4 50
β-function at the IP [m] 05 10 08 11
No Ions per bunch [] 07 14
Transv normalised emittance [] 15 15
RMS Beam Size at IP [] 159 339 266 88
RMS bunch length [] 794 8
Number of bunches 592 358 358 432
Peak Luminosity [] 1 (Pb-Pb) 110 (p-Pb)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Best injector performance achieved in 2013 p-Pb run
Average beam parameters from 2013 are assumed as VERY conservative baseline for FCC-hh
Improvements are already under study for HL-LHC
Geometric emittance at injection gt protons ndash possible issue for aperture choice
11
Beam and Luminosity Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
During the beams are in collision the instantaneous value of the luminosity will change
The beam evolution with time is obtained by solving a system of four differential equations (dominant effects only shown here more included in simulations)
with
revolution freq no bunchesbeam β-function at IP no particlesbunch geom emittances bunch length
total cross-section IBS growth rate rad damping rateIntensity
Hor Emittance
Ver Emittance
Bunch Length
Analytical solution difficult due to dependence of on
12
Effects on the Emittance ndash a new regime
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Intra-Beam Scattering (IBS) (Synchrotron) Radiation Damping
Emittance Growth Emittance Shrinkage
Growth rate dynamically changing with beam properties
Damping rate is constant for a given energy
IBS is weak for initial beam parameters but increases with decreasing emittance
Multiple small-angle Coulomb scattering within a charged particle beam
A charged particle radiates energy when itis accelerated ie bend on its circular orbit
Fast emittance decrease at the beginning of the fill until IBS becomes strong enough to counteract the radiation damping
Growth Times Unit FCC 50Z TeV
[h] 291
[h] 300
Damping Times Unit FCC 50Z TeV
[h] 024
[h] 049
13
BEAM AND LUMINOSITY EVOLUTION
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Pb-Pb
14
Pb-Pb Beam Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
bull Red tracking simulation taking into account IBS rad damping burn-off hellip
bull Black numerical solution of the ODE system on slide 7 using J Weirsquos analytical IBS formalism
rarr emittances and bunch length become very small
bull Green ddt = 0 artificial longitudinal blow-up to = 8cm
bull Blue artificial longitudinal and transverse blow-up to = 8cm and J Wei Evolution of Hadron Beams under Intrabeam
Scattering ConfProc C930517 (1993) 3651-3653 PAC 1993
Transverse Emittance
Bunch Length
Intensity
15
Pb-Pb Luminosity Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 0006 26
[Hzmb] 0017 73
[] 013 578
Summary for free beam evolution (no artificial blow-up)
If the beam dimensions become too small and artificial blow-up has to be used the luminosity will be affectedbull Peak Enhancement for long blow-up
since long and horizontal IBS are reduced due to larger rarr smaller
bull Reduced luminosity due to blown-up
16
Pb-Pb Average Luminosity
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
= time in collisions rarr to be optimised
= turn-around time = time dump rarr next collisions
Assumption (cycle time FCC without injections) (no injections from LHC)
Average Luminosity per hour
For free beam parameter evolution red case from previous slide
Max at
inst
17
Pb-Pb Integrated Luminosity per Run
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
bull Assumption
bull Consider more LHC injectionsrarr max (= FCC Length)rarr Dwell time at FCC inj plateau
rarr lengthen rarr Particle losses (amp emittance
growth)rarr Loss rate of Pb at injectionrarr Total beam intensity
rarr ltgt ltgt
Int Luminosity per run
Opt Time in Collisions
18
BEAM AND LUMINOSITY EVOLUTION
LHC has shown that p-Pb injecting and ramping with unequal revolution frequencies is feasible This will work for injection (provided we keep independent RF systems) and may not even be necessary in FCC ring
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
p-Pb
19
p-Pb Beam Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam Size Bunch Length
Intensity
Initial conditionsbull Pb-beam as for Pb-Pb operationbull Equal beam sizes σ for p and Pbbull Rad damping
rarr bull IBS scales with bull
rarr Fast Pb burn-off while const
20
p-Pb Luminosity Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 05 213
[Hzmb] 28 1192
[] 487 21068
Peak shifted to later timesrarr p shrinks slower than Pb
Luminosity decay slowerrarr constrarr 1e-Luminosity lifetime 14h
p-Pb Luminosity vs Turn-Around Time
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 201521
Max at
Int Luminosity per run
Opt Time in Collisions
For rarr Optimised fill length = 65h rarr ltgtrun 17 could give higher ltgtrun rarr But uncertainty on prediction
significantly enhanced rarr Early beam aborts and longer inj
times due to lost beams in the LHC reduce ltgtrun
rarr injection and fill times are both in the order of 10h
22
POTENTIAL LIMITATIONS
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
23
Beam-Beam Tune Shift
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam-Beam Parameter per Experiment
Unit LHC Designp-p
LHC DesignPb-Pb
FCCPb-Pb
FCCp-Pb
Initial [ 37 018 037 037
Peak [ 37 018 14 83
Beam-beam tune shift per experimentbull Beam m receives kick from Beam n bull uv =x y
The tune shift due to beam-beam interactions remains well below assumed limit for Pb-Pb but comes close to the limit for Pb in p-Pb collisions
Pb-Pb
p-Pb
γ-γ and γ-A processes in Pb-Pb collisions at FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015 24
2
208208 208
208208
20882 82 82
82 82 8
08208 82 208 82 82 20
20 20
8 8
8 2
8
0
1
7 82
B
BFPP2 Pb Pb Pb Pb 2e 10 mb
FPP1 Pb Pb Pb e 354 b 001235
EMD1 Pb Pb Pb n 20
00Pb
b
2
P
500
0
208208 82 8208 02 2 6 88 2 2
b 000485EMD2 Pb Pb P b 2n
35 b 000970Pb
Each of these makes a secondary beam emerging from the IP with rigidity change
Pb1 11 m mQ Q
Extensively discussed for LHC
Hadronic cross section is 8 b (so much less power in debris)
25
BFPP1 Beam Power in Pb-Pb for FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Countermeasures (eg DS collimators) have to be considered in initial lattice amp hardware design
FCC-PbPb
nominal LHC P 26Wrarr already expected to cause operational problems and poaaible long-term damage
41 PeV
BFPP1 Beam power 17 kW (peak)cP L E
26
Secondary beams from Pb-Pb collisions (Lattice V4 baseline)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
IP
208Pb81+ (BFPP1)208Pb80+ (BFPP2)
206Pb82+ (EMD2)
207Pb82+ (EMD1)
M Schaumann Workshop on Ions at the FCC CERN
27
Smaller Z Ions ndash Impact on hadronic event count
20140922
bull Lower Z possibly higher available from injectors
bull Contribution of ultra-peripheral electromagnetic processes to the total cross-section would be reduced
Increased luminosity lifetime more particles available for hadronic interactions
Reduced secondary beam power emerging from collision point
bull Radiation damping rate does not change much for Zgt60o
o Lower Z beams would put more burn-off into hadronic events
o Worth considering small Z reduction from Pb to eg
(6--8)hadronic
BFPP EMD
hh tot
h
N Ldt N Z
Z
( )(Pb)L ZL
28
Heavy-Ion Beam Parameter Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
29
Heavy-Ion Luminosity Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
30
Future work neededbull Number of active experiments to be considered very carefully
1 or 2 bull Counter measures for (few kW) secondary beams from IPs
ndash Robust collimatorsabsorbers in dispersion suppressorsndash Shower calculations magnet quench risks etc
bull Include heavy ion beams in future evolution of injector chainndash Maximise no of ions injected in colliderndash Do we have to live with present limits in SPS
bull Extend LHC heavy-ion collimation studies to FCCndash Does synchrotron radiation damping solve this for us
bull Vacuum effects
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Collaboration welcome
31
Conclusions and Outlookbull With very conservative assumptions (past LHC Pb
beams) FCC-hh has clear potential for high luminosity nucleus-nucleus and proton-nucleus collisions
bull New highly efficient collider regime of strong radiation damping can be fully exploited with heavy-ion beams
bull Photon-photon and photonuclear processes create powerful secondary beams emerging from IPndash Foresee counter-measures from the start (cf LHC experience)
bull Extreme luminosity burn-off is a fact of nature ndash physics community might want to consider somewhat lower-Z species
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
32
BACKUP SLIDES
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
8
CERN Heavy-Ion Injector Complexbull Present study very conservatively assumes the Pb
injector performance achieved for LHC p-Pb run in 2013
bull Potential upgrades needing studyndash Better ion source ndash Upgradereplacement of LEIR faster cooling higher injection
into PS ndash Degradation of bunches along trains at SPS injection
(alternatives to fixed harmonic acceleration with present200 MHz RF system)
bull LHC as HEB injector into FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Heavy Ion Pre-Accelerator Chain
9JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Straw-man assumption to estimate (conservative) beam parameters and luminosity LHC as it is today but cycling to 33 Z TeV is assumed to be the injector for FCC-hh
Present heavy-ion pre-injectors
LEIRHI source + LINAC 3
Baseline Inject one LHC beam into 14 FCC no waiting ramp immediately
PS
SPS
LHCFCC
10
Pb Beam Parameters in LHC and FCC-hh
LHCDesign
LHC 2011
LHC 2013
FCC-hh
Beam Energy [Z TeV] 7 35 4 50
β-function at the IP [m] 05 10 08 11
No Ions per bunch [] 07 14
Transv normalised emittance [] 15 15
RMS Beam Size at IP [] 159 339 266 88
RMS bunch length [] 794 8
Number of bunches 592 358 358 432
Peak Luminosity [] 1 (Pb-Pb) 110 (p-Pb)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Best injector performance achieved in 2013 p-Pb run
Average beam parameters from 2013 are assumed as VERY conservative baseline for FCC-hh
Improvements are already under study for HL-LHC
Geometric emittance at injection gt protons ndash possible issue for aperture choice
11
Beam and Luminosity Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
During the beams are in collision the instantaneous value of the luminosity will change
The beam evolution with time is obtained by solving a system of four differential equations (dominant effects only shown here more included in simulations)
with
revolution freq no bunchesbeam β-function at IP no particlesbunch geom emittances bunch length
total cross-section IBS growth rate rad damping rateIntensity
Hor Emittance
Ver Emittance
Bunch Length
Analytical solution difficult due to dependence of on
12
Effects on the Emittance ndash a new regime
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Intra-Beam Scattering (IBS) (Synchrotron) Radiation Damping
Emittance Growth Emittance Shrinkage
Growth rate dynamically changing with beam properties
Damping rate is constant for a given energy
IBS is weak for initial beam parameters but increases with decreasing emittance
Multiple small-angle Coulomb scattering within a charged particle beam
A charged particle radiates energy when itis accelerated ie bend on its circular orbit
Fast emittance decrease at the beginning of the fill until IBS becomes strong enough to counteract the radiation damping
Growth Times Unit FCC 50Z TeV
[h] 291
[h] 300
Damping Times Unit FCC 50Z TeV
[h] 024
[h] 049
13
BEAM AND LUMINOSITY EVOLUTION
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Pb-Pb
14
Pb-Pb Beam Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
bull Red tracking simulation taking into account IBS rad damping burn-off hellip
bull Black numerical solution of the ODE system on slide 7 using J Weirsquos analytical IBS formalism
rarr emittances and bunch length become very small
bull Green ddt = 0 artificial longitudinal blow-up to = 8cm
bull Blue artificial longitudinal and transverse blow-up to = 8cm and J Wei Evolution of Hadron Beams under Intrabeam
Scattering ConfProc C930517 (1993) 3651-3653 PAC 1993
Transverse Emittance
Bunch Length
Intensity
15
Pb-Pb Luminosity Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 0006 26
[Hzmb] 0017 73
[] 013 578
Summary for free beam evolution (no artificial blow-up)
If the beam dimensions become too small and artificial blow-up has to be used the luminosity will be affectedbull Peak Enhancement for long blow-up
since long and horizontal IBS are reduced due to larger rarr smaller
bull Reduced luminosity due to blown-up
16
Pb-Pb Average Luminosity
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
= time in collisions rarr to be optimised
= turn-around time = time dump rarr next collisions
Assumption (cycle time FCC without injections) (no injections from LHC)
Average Luminosity per hour
For free beam parameter evolution red case from previous slide
Max at
inst
17
Pb-Pb Integrated Luminosity per Run
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
bull Assumption
bull Consider more LHC injectionsrarr max (= FCC Length)rarr Dwell time at FCC inj plateau
rarr lengthen rarr Particle losses (amp emittance
growth)rarr Loss rate of Pb at injectionrarr Total beam intensity
rarr ltgt ltgt
Int Luminosity per run
Opt Time in Collisions
18
BEAM AND LUMINOSITY EVOLUTION
LHC has shown that p-Pb injecting and ramping with unequal revolution frequencies is feasible This will work for injection (provided we keep independent RF systems) and may not even be necessary in FCC ring
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
p-Pb
19
p-Pb Beam Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam Size Bunch Length
Intensity
Initial conditionsbull Pb-beam as for Pb-Pb operationbull Equal beam sizes σ for p and Pbbull Rad damping
rarr bull IBS scales with bull
rarr Fast Pb burn-off while const
20
p-Pb Luminosity Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 05 213
[Hzmb] 28 1192
[] 487 21068
Peak shifted to later timesrarr p shrinks slower than Pb
Luminosity decay slowerrarr constrarr 1e-Luminosity lifetime 14h
p-Pb Luminosity vs Turn-Around Time
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 201521
Max at
Int Luminosity per run
Opt Time in Collisions
For rarr Optimised fill length = 65h rarr ltgtrun 17 could give higher ltgtrun rarr But uncertainty on prediction
significantly enhanced rarr Early beam aborts and longer inj
times due to lost beams in the LHC reduce ltgtrun
rarr injection and fill times are both in the order of 10h
22
POTENTIAL LIMITATIONS
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
23
Beam-Beam Tune Shift
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam-Beam Parameter per Experiment
Unit LHC Designp-p
LHC DesignPb-Pb
FCCPb-Pb
FCCp-Pb
Initial [ 37 018 037 037
Peak [ 37 018 14 83
Beam-beam tune shift per experimentbull Beam m receives kick from Beam n bull uv =x y
The tune shift due to beam-beam interactions remains well below assumed limit for Pb-Pb but comes close to the limit for Pb in p-Pb collisions
Pb-Pb
p-Pb
γ-γ and γ-A processes in Pb-Pb collisions at FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015 24
2
208208 208
208208
20882 82 82
82 82 8
08208 82 208 82 82 20
20 20
8 8
8 2
8
0
1
7 82
B
BFPP2 Pb Pb Pb Pb 2e 10 mb
FPP1 Pb Pb Pb e 354 b 001235
EMD1 Pb Pb Pb n 20
00Pb
b
2
P
500
0
208208 82 8208 02 2 6 88 2 2
b 000485EMD2 Pb Pb P b 2n
35 b 000970Pb
Each of these makes a secondary beam emerging from the IP with rigidity change
Pb1 11 m mQ Q
Extensively discussed for LHC
Hadronic cross section is 8 b (so much less power in debris)
25
BFPP1 Beam Power in Pb-Pb for FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Countermeasures (eg DS collimators) have to be considered in initial lattice amp hardware design
FCC-PbPb
nominal LHC P 26Wrarr already expected to cause operational problems and poaaible long-term damage
41 PeV
BFPP1 Beam power 17 kW (peak)cP L E
26
Secondary beams from Pb-Pb collisions (Lattice V4 baseline)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
IP
208Pb81+ (BFPP1)208Pb80+ (BFPP2)
206Pb82+ (EMD2)
207Pb82+ (EMD1)
M Schaumann Workshop on Ions at the FCC CERN
27
Smaller Z Ions ndash Impact on hadronic event count
20140922
bull Lower Z possibly higher available from injectors
bull Contribution of ultra-peripheral electromagnetic processes to the total cross-section would be reduced
Increased luminosity lifetime more particles available for hadronic interactions
Reduced secondary beam power emerging from collision point
bull Radiation damping rate does not change much for Zgt60o
o Lower Z beams would put more burn-off into hadronic events
o Worth considering small Z reduction from Pb to eg
(6--8)hadronic
BFPP EMD
hh tot
h
N Ldt N Z
Z
( )(Pb)L ZL
28
Heavy-Ion Beam Parameter Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
29
Heavy-Ion Luminosity Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
30
Future work neededbull Number of active experiments to be considered very carefully
1 or 2 bull Counter measures for (few kW) secondary beams from IPs
ndash Robust collimatorsabsorbers in dispersion suppressorsndash Shower calculations magnet quench risks etc
bull Include heavy ion beams in future evolution of injector chainndash Maximise no of ions injected in colliderndash Do we have to live with present limits in SPS
bull Extend LHC heavy-ion collimation studies to FCCndash Does synchrotron radiation damping solve this for us
bull Vacuum effects
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Collaboration welcome
31
Conclusions and Outlookbull With very conservative assumptions (past LHC Pb
beams) FCC-hh has clear potential for high luminosity nucleus-nucleus and proton-nucleus collisions
bull New highly efficient collider regime of strong radiation damping can be fully exploited with heavy-ion beams
bull Photon-photon and photonuclear processes create powerful secondary beams emerging from IPndash Foresee counter-measures from the start (cf LHC experience)
bull Extreme luminosity burn-off is a fact of nature ndash physics community might want to consider somewhat lower-Z species
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
32
BACKUP SLIDES
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Heavy Ion Pre-Accelerator Chain
9JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Straw-man assumption to estimate (conservative) beam parameters and luminosity LHC as it is today but cycling to 33 Z TeV is assumed to be the injector for FCC-hh
Present heavy-ion pre-injectors
LEIRHI source + LINAC 3
Baseline Inject one LHC beam into 14 FCC no waiting ramp immediately
PS
SPS
LHCFCC
10
Pb Beam Parameters in LHC and FCC-hh
LHCDesign
LHC 2011
LHC 2013
FCC-hh
Beam Energy [Z TeV] 7 35 4 50
β-function at the IP [m] 05 10 08 11
No Ions per bunch [] 07 14
Transv normalised emittance [] 15 15
RMS Beam Size at IP [] 159 339 266 88
RMS bunch length [] 794 8
Number of bunches 592 358 358 432
Peak Luminosity [] 1 (Pb-Pb) 110 (p-Pb)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Best injector performance achieved in 2013 p-Pb run
Average beam parameters from 2013 are assumed as VERY conservative baseline for FCC-hh
Improvements are already under study for HL-LHC
Geometric emittance at injection gt protons ndash possible issue for aperture choice
11
Beam and Luminosity Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
During the beams are in collision the instantaneous value of the luminosity will change
The beam evolution with time is obtained by solving a system of four differential equations (dominant effects only shown here more included in simulations)
with
revolution freq no bunchesbeam β-function at IP no particlesbunch geom emittances bunch length
total cross-section IBS growth rate rad damping rateIntensity
Hor Emittance
Ver Emittance
Bunch Length
Analytical solution difficult due to dependence of on
12
Effects on the Emittance ndash a new regime
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Intra-Beam Scattering (IBS) (Synchrotron) Radiation Damping
Emittance Growth Emittance Shrinkage
Growth rate dynamically changing with beam properties
Damping rate is constant for a given energy
IBS is weak for initial beam parameters but increases with decreasing emittance
Multiple small-angle Coulomb scattering within a charged particle beam
A charged particle radiates energy when itis accelerated ie bend on its circular orbit
Fast emittance decrease at the beginning of the fill until IBS becomes strong enough to counteract the radiation damping
Growth Times Unit FCC 50Z TeV
[h] 291
[h] 300
Damping Times Unit FCC 50Z TeV
[h] 024
[h] 049
13
BEAM AND LUMINOSITY EVOLUTION
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Pb-Pb
14
Pb-Pb Beam Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
bull Red tracking simulation taking into account IBS rad damping burn-off hellip
bull Black numerical solution of the ODE system on slide 7 using J Weirsquos analytical IBS formalism
rarr emittances and bunch length become very small
bull Green ddt = 0 artificial longitudinal blow-up to = 8cm
bull Blue artificial longitudinal and transverse blow-up to = 8cm and J Wei Evolution of Hadron Beams under Intrabeam
Scattering ConfProc C930517 (1993) 3651-3653 PAC 1993
Transverse Emittance
Bunch Length
Intensity
15
Pb-Pb Luminosity Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 0006 26
[Hzmb] 0017 73
[] 013 578
Summary for free beam evolution (no artificial blow-up)
If the beam dimensions become too small and artificial blow-up has to be used the luminosity will be affectedbull Peak Enhancement for long blow-up
since long and horizontal IBS are reduced due to larger rarr smaller
bull Reduced luminosity due to blown-up
16
Pb-Pb Average Luminosity
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
= time in collisions rarr to be optimised
= turn-around time = time dump rarr next collisions
Assumption (cycle time FCC without injections) (no injections from LHC)
Average Luminosity per hour
For free beam parameter evolution red case from previous slide
Max at
inst
17
Pb-Pb Integrated Luminosity per Run
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
bull Assumption
bull Consider more LHC injectionsrarr max (= FCC Length)rarr Dwell time at FCC inj plateau
rarr lengthen rarr Particle losses (amp emittance
growth)rarr Loss rate of Pb at injectionrarr Total beam intensity
rarr ltgt ltgt
Int Luminosity per run
Opt Time in Collisions
18
BEAM AND LUMINOSITY EVOLUTION
LHC has shown that p-Pb injecting and ramping with unequal revolution frequencies is feasible This will work for injection (provided we keep independent RF systems) and may not even be necessary in FCC ring
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
p-Pb
19
p-Pb Beam Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam Size Bunch Length
Intensity
Initial conditionsbull Pb-beam as for Pb-Pb operationbull Equal beam sizes σ for p and Pbbull Rad damping
rarr bull IBS scales with bull
rarr Fast Pb burn-off while const
20
p-Pb Luminosity Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 05 213
[Hzmb] 28 1192
[] 487 21068
Peak shifted to later timesrarr p shrinks slower than Pb
Luminosity decay slowerrarr constrarr 1e-Luminosity lifetime 14h
p-Pb Luminosity vs Turn-Around Time
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 201521
Max at
Int Luminosity per run
Opt Time in Collisions
For rarr Optimised fill length = 65h rarr ltgtrun 17 could give higher ltgtrun rarr But uncertainty on prediction
significantly enhanced rarr Early beam aborts and longer inj
times due to lost beams in the LHC reduce ltgtrun
rarr injection and fill times are both in the order of 10h
22
POTENTIAL LIMITATIONS
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
23
Beam-Beam Tune Shift
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam-Beam Parameter per Experiment
Unit LHC Designp-p
LHC DesignPb-Pb
FCCPb-Pb
FCCp-Pb
Initial [ 37 018 037 037
Peak [ 37 018 14 83
Beam-beam tune shift per experimentbull Beam m receives kick from Beam n bull uv =x y
The tune shift due to beam-beam interactions remains well below assumed limit for Pb-Pb but comes close to the limit for Pb in p-Pb collisions
Pb-Pb
p-Pb
γ-γ and γ-A processes in Pb-Pb collisions at FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015 24
2
208208 208
208208
20882 82 82
82 82 8
08208 82 208 82 82 20
20 20
8 8
8 2
8
0
1
7 82
B
BFPP2 Pb Pb Pb Pb 2e 10 mb
FPP1 Pb Pb Pb e 354 b 001235
EMD1 Pb Pb Pb n 20
00Pb
b
2
P
500
0
208208 82 8208 02 2 6 88 2 2
b 000485EMD2 Pb Pb P b 2n
35 b 000970Pb
Each of these makes a secondary beam emerging from the IP with rigidity change
Pb1 11 m mQ Q
Extensively discussed for LHC
Hadronic cross section is 8 b (so much less power in debris)
25
BFPP1 Beam Power in Pb-Pb for FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Countermeasures (eg DS collimators) have to be considered in initial lattice amp hardware design
FCC-PbPb
nominal LHC P 26Wrarr already expected to cause operational problems and poaaible long-term damage
41 PeV
BFPP1 Beam power 17 kW (peak)cP L E
26
Secondary beams from Pb-Pb collisions (Lattice V4 baseline)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
IP
208Pb81+ (BFPP1)208Pb80+ (BFPP2)
206Pb82+ (EMD2)
207Pb82+ (EMD1)
M Schaumann Workshop on Ions at the FCC CERN
27
Smaller Z Ions ndash Impact on hadronic event count
20140922
bull Lower Z possibly higher available from injectors
bull Contribution of ultra-peripheral electromagnetic processes to the total cross-section would be reduced
Increased luminosity lifetime more particles available for hadronic interactions
Reduced secondary beam power emerging from collision point
bull Radiation damping rate does not change much for Zgt60o
o Lower Z beams would put more burn-off into hadronic events
o Worth considering small Z reduction from Pb to eg
(6--8)hadronic
BFPP EMD
hh tot
h
N Ldt N Z
Z
( )(Pb)L ZL
28
Heavy-Ion Beam Parameter Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
29
Heavy-Ion Luminosity Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
30
Future work neededbull Number of active experiments to be considered very carefully
1 or 2 bull Counter measures for (few kW) secondary beams from IPs
ndash Robust collimatorsabsorbers in dispersion suppressorsndash Shower calculations magnet quench risks etc
bull Include heavy ion beams in future evolution of injector chainndash Maximise no of ions injected in colliderndash Do we have to live with present limits in SPS
bull Extend LHC heavy-ion collimation studies to FCCndash Does synchrotron radiation damping solve this for us
bull Vacuum effects
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Collaboration welcome
31
Conclusions and Outlookbull With very conservative assumptions (past LHC Pb
beams) FCC-hh has clear potential for high luminosity nucleus-nucleus and proton-nucleus collisions
bull New highly efficient collider regime of strong radiation damping can be fully exploited with heavy-ion beams
bull Photon-photon and photonuclear processes create powerful secondary beams emerging from IPndash Foresee counter-measures from the start (cf LHC experience)
bull Extreme luminosity burn-off is a fact of nature ndash physics community might want to consider somewhat lower-Z species
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
32
BACKUP SLIDES
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
10
Pb Beam Parameters in LHC and FCC-hh
LHCDesign
LHC 2011
LHC 2013
FCC-hh
Beam Energy [Z TeV] 7 35 4 50
β-function at the IP [m] 05 10 08 11
No Ions per bunch [] 07 14
Transv normalised emittance [] 15 15
RMS Beam Size at IP [] 159 339 266 88
RMS bunch length [] 794 8
Number of bunches 592 358 358 432
Peak Luminosity [] 1 (Pb-Pb) 110 (p-Pb)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Best injector performance achieved in 2013 p-Pb run
Average beam parameters from 2013 are assumed as VERY conservative baseline for FCC-hh
Improvements are already under study for HL-LHC
Geometric emittance at injection gt protons ndash possible issue for aperture choice
11
Beam and Luminosity Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
During the beams are in collision the instantaneous value of the luminosity will change
The beam evolution with time is obtained by solving a system of four differential equations (dominant effects only shown here more included in simulations)
with
revolution freq no bunchesbeam β-function at IP no particlesbunch geom emittances bunch length
total cross-section IBS growth rate rad damping rateIntensity
Hor Emittance
Ver Emittance
Bunch Length
Analytical solution difficult due to dependence of on
12
Effects on the Emittance ndash a new regime
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Intra-Beam Scattering (IBS) (Synchrotron) Radiation Damping
Emittance Growth Emittance Shrinkage
Growth rate dynamically changing with beam properties
Damping rate is constant for a given energy
IBS is weak for initial beam parameters but increases with decreasing emittance
Multiple small-angle Coulomb scattering within a charged particle beam
A charged particle radiates energy when itis accelerated ie bend on its circular orbit
Fast emittance decrease at the beginning of the fill until IBS becomes strong enough to counteract the radiation damping
Growth Times Unit FCC 50Z TeV
[h] 291
[h] 300
Damping Times Unit FCC 50Z TeV
[h] 024
[h] 049
13
BEAM AND LUMINOSITY EVOLUTION
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Pb-Pb
14
Pb-Pb Beam Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
bull Red tracking simulation taking into account IBS rad damping burn-off hellip
bull Black numerical solution of the ODE system on slide 7 using J Weirsquos analytical IBS formalism
rarr emittances and bunch length become very small
bull Green ddt = 0 artificial longitudinal blow-up to = 8cm
bull Blue artificial longitudinal and transverse blow-up to = 8cm and J Wei Evolution of Hadron Beams under Intrabeam
Scattering ConfProc C930517 (1993) 3651-3653 PAC 1993
Transverse Emittance
Bunch Length
Intensity
15
Pb-Pb Luminosity Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 0006 26
[Hzmb] 0017 73
[] 013 578
Summary for free beam evolution (no artificial blow-up)
If the beam dimensions become too small and artificial blow-up has to be used the luminosity will be affectedbull Peak Enhancement for long blow-up
since long and horizontal IBS are reduced due to larger rarr smaller
bull Reduced luminosity due to blown-up
16
Pb-Pb Average Luminosity
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
= time in collisions rarr to be optimised
= turn-around time = time dump rarr next collisions
Assumption (cycle time FCC without injections) (no injections from LHC)
Average Luminosity per hour
For free beam parameter evolution red case from previous slide
Max at
inst
17
Pb-Pb Integrated Luminosity per Run
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
bull Assumption
bull Consider more LHC injectionsrarr max (= FCC Length)rarr Dwell time at FCC inj plateau
rarr lengthen rarr Particle losses (amp emittance
growth)rarr Loss rate of Pb at injectionrarr Total beam intensity
rarr ltgt ltgt
Int Luminosity per run
Opt Time in Collisions
18
BEAM AND LUMINOSITY EVOLUTION
LHC has shown that p-Pb injecting and ramping with unequal revolution frequencies is feasible This will work for injection (provided we keep independent RF systems) and may not even be necessary in FCC ring
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
p-Pb
19
p-Pb Beam Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam Size Bunch Length
Intensity
Initial conditionsbull Pb-beam as for Pb-Pb operationbull Equal beam sizes σ for p and Pbbull Rad damping
rarr bull IBS scales with bull
rarr Fast Pb burn-off while const
20
p-Pb Luminosity Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 05 213
[Hzmb] 28 1192
[] 487 21068
Peak shifted to later timesrarr p shrinks slower than Pb
Luminosity decay slowerrarr constrarr 1e-Luminosity lifetime 14h
p-Pb Luminosity vs Turn-Around Time
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 201521
Max at
Int Luminosity per run
Opt Time in Collisions
For rarr Optimised fill length = 65h rarr ltgtrun 17 could give higher ltgtrun rarr But uncertainty on prediction
significantly enhanced rarr Early beam aborts and longer inj
times due to lost beams in the LHC reduce ltgtrun
rarr injection and fill times are both in the order of 10h
22
POTENTIAL LIMITATIONS
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
23
Beam-Beam Tune Shift
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam-Beam Parameter per Experiment
Unit LHC Designp-p
LHC DesignPb-Pb
FCCPb-Pb
FCCp-Pb
Initial [ 37 018 037 037
Peak [ 37 018 14 83
Beam-beam tune shift per experimentbull Beam m receives kick from Beam n bull uv =x y
The tune shift due to beam-beam interactions remains well below assumed limit for Pb-Pb but comes close to the limit for Pb in p-Pb collisions
Pb-Pb
p-Pb
γ-γ and γ-A processes in Pb-Pb collisions at FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015 24
2
208208 208
208208
20882 82 82
82 82 8
08208 82 208 82 82 20
20 20
8 8
8 2
8
0
1
7 82
B
BFPP2 Pb Pb Pb Pb 2e 10 mb
FPP1 Pb Pb Pb e 354 b 001235
EMD1 Pb Pb Pb n 20
00Pb
b
2
P
500
0
208208 82 8208 02 2 6 88 2 2
b 000485EMD2 Pb Pb P b 2n
35 b 000970Pb
Each of these makes a secondary beam emerging from the IP with rigidity change
Pb1 11 m mQ Q
Extensively discussed for LHC
Hadronic cross section is 8 b (so much less power in debris)
25
BFPP1 Beam Power in Pb-Pb for FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Countermeasures (eg DS collimators) have to be considered in initial lattice amp hardware design
FCC-PbPb
nominal LHC P 26Wrarr already expected to cause operational problems and poaaible long-term damage
41 PeV
BFPP1 Beam power 17 kW (peak)cP L E
26
Secondary beams from Pb-Pb collisions (Lattice V4 baseline)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
IP
208Pb81+ (BFPP1)208Pb80+ (BFPP2)
206Pb82+ (EMD2)
207Pb82+ (EMD1)
M Schaumann Workshop on Ions at the FCC CERN
27
Smaller Z Ions ndash Impact on hadronic event count
20140922
bull Lower Z possibly higher available from injectors
bull Contribution of ultra-peripheral electromagnetic processes to the total cross-section would be reduced
Increased luminosity lifetime more particles available for hadronic interactions
Reduced secondary beam power emerging from collision point
bull Radiation damping rate does not change much for Zgt60o
o Lower Z beams would put more burn-off into hadronic events
o Worth considering small Z reduction from Pb to eg
(6--8)hadronic
BFPP EMD
hh tot
h
N Ldt N Z
Z
( )(Pb)L ZL
28
Heavy-Ion Beam Parameter Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
29
Heavy-Ion Luminosity Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
30
Future work neededbull Number of active experiments to be considered very carefully
1 or 2 bull Counter measures for (few kW) secondary beams from IPs
ndash Robust collimatorsabsorbers in dispersion suppressorsndash Shower calculations magnet quench risks etc
bull Include heavy ion beams in future evolution of injector chainndash Maximise no of ions injected in colliderndash Do we have to live with present limits in SPS
bull Extend LHC heavy-ion collimation studies to FCCndash Does synchrotron radiation damping solve this for us
bull Vacuum effects
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Collaboration welcome
31
Conclusions and Outlookbull With very conservative assumptions (past LHC Pb
beams) FCC-hh has clear potential for high luminosity nucleus-nucleus and proton-nucleus collisions
bull New highly efficient collider regime of strong radiation damping can be fully exploited with heavy-ion beams
bull Photon-photon and photonuclear processes create powerful secondary beams emerging from IPndash Foresee counter-measures from the start (cf LHC experience)
bull Extreme luminosity burn-off is a fact of nature ndash physics community might want to consider somewhat lower-Z species
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
32
BACKUP SLIDES
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
11
Beam and Luminosity Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
During the beams are in collision the instantaneous value of the luminosity will change
The beam evolution with time is obtained by solving a system of four differential equations (dominant effects only shown here more included in simulations)
with
revolution freq no bunchesbeam β-function at IP no particlesbunch geom emittances bunch length
total cross-section IBS growth rate rad damping rateIntensity
Hor Emittance
Ver Emittance
Bunch Length
Analytical solution difficult due to dependence of on
12
Effects on the Emittance ndash a new regime
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Intra-Beam Scattering (IBS) (Synchrotron) Radiation Damping
Emittance Growth Emittance Shrinkage
Growth rate dynamically changing with beam properties
Damping rate is constant for a given energy
IBS is weak for initial beam parameters but increases with decreasing emittance
Multiple small-angle Coulomb scattering within a charged particle beam
A charged particle radiates energy when itis accelerated ie bend on its circular orbit
Fast emittance decrease at the beginning of the fill until IBS becomes strong enough to counteract the radiation damping
Growth Times Unit FCC 50Z TeV
[h] 291
[h] 300
Damping Times Unit FCC 50Z TeV
[h] 024
[h] 049
13
BEAM AND LUMINOSITY EVOLUTION
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Pb-Pb
14
Pb-Pb Beam Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
bull Red tracking simulation taking into account IBS rad damping burn-off hellip
bull Black numerical solution of the ODE system on slide 7 using J Weirsquos analytical IBS formalism
rarr emittances and bunch length become very small
bull Green ddt = 0 artificial longitudinal blow-up to = 8cm
bull Blue artificial longitudinal and transverse blow-up to = 8cm and J Wei Evolution of Hadron Beams under Intrabeam
Scattering ConfProc C930517 (1993) 3651-3653 PAC 1993
Transverse Emittance
Bunch Length
Intensity
15
Pb-Pb Luminosity Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 0006 26
[Hzmb] 0017 73
[] 013 578
Summary for free beam evolution (no artificial blow-up)
If the beam dimensions become too small and artificial blow-up has to be used the luminosity will be affectedbull Peak Enhancement for long blow-up
since long and horizontal IBS are reduced due to larger rarr smaller
bull Reduced luminosity due to blown-up
16
Pb-Pb Average Luminosity
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
= time in collisions rarr to be optimised
= turn-around time = time dump rarr next collisions
Assumption (cycle time FCC without injections) (no injections from LHC)
Average Luminosity per hour
For free beam parameter evolution red case from previous slide
Max at
inst
17
Pb-Pb Integrated Luminosity per Run
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
bull Assumption
bull Consider more LHC injectionsrarr max (= FCC Length)rarr Dwell time at FCC inj plateau
rarr lengthen rarr Particle losses (amp emittance
growth)rarr Loss rate of Pb at injectionrarr Total beam intensity
rarr ltgt ltgt
Int Luminosity per run
Opt Time in Collisions
18
BEAM AND LUMINOSITY EVOLUTION
LHC has shown that p-Pb injecting and ramping with unequal revolution frequencies is feasible This will work for injection (provided we keep independent RF systems) and may not even be necessary in FCC ring
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
p-Pb
19
p-Pb Beam Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam Size Bunch Length
Intensity
Initial conditionsbull Pb-beam as for Pb-Pb operationbull Equal beam sizes σ for p and Pbbull Rad damping
rarr bull IBS scales with bull
rarr Fast Pb burn-off while const
20
p-Pb Luminosity Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 05 213
[Hzmb] 28 1192
[] 487 21068
Peak shifted to later timesrarr p shrinks slower than Pb
Luminosity decay slowerrarr constrarr 1e-Luminosity lifetime 14h
p-Pb Luminosity vs Turn-Around Time
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 201521
Max at
Int Luminosity per run
Opt Time in Collisions
For rarr Optimised fill length = 65h rarr ltgtrun 17 could give higher ltgtrun rarr But uncertainty on prediction
significantly enhanced rarr Early beam aborts and longer inj
times due to lost beams in the LHC reduce ltgtrun
rarr injection and fill times are both in the order of 10h
22
POTENTIAL LIMITATIONS
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
23
Beam-Beam Tune Shift
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam-Beam Parameter per Experiment
Unit LHC Designp-p
LHC DesignPb-Pb
FCCPb-Pb
FCCp-Pb
Initial [ 37 018 037 037
Peak [ 37 018 14 83
Beam-beam tune shift per experimentbull Beam m receives kick from Beam n bull uv =x y
The tune shift due to beam-beam interactions remains well below assumed limit for Pb-Pb but comes close to the limit for Pb in p-Pb collisions
Pb-Pb
p-Pb
γ-γ and γ-A processes in Pb-Pb collisions at FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015 24
2
208208 208
208208
20882 82 82
82 82 8
08208 82 208 82 82 20
20 20
8 8
8 2
8
0
1
7 82
B
BFPP2 Pb Pb Pb Pb 2e 10 mb
FPP1 Pb Pb Pb e 354 b 001235
EMD1 Pb Pb Pb n 20
00Pb
b
2
P
500
0
208208 82 8208 02 2 6 88 2 2
b 000485EMD2 Pb Pb P b 2n
35 b 000970Pb
Each of these makes a secondary beam emerging from the IP with rigidity change
Pb1 11 m mQ Q
Extensively discussed for LHC
Hadronic cross section is 8 b (so much less power in debris)
25
BFPP1 Beam Power in Pb-Pb for FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Countermeasures (eg DS collimators) have to be considered in initial lattice amp hardware design
FCC-PbPb
nominal LHC P 26Wrarr already expected to cause operational problems and poaaible long-term damage
41 PeV
BFPP1 Beam power 17 kW (peak)cP L E
26
Secondary beams from Pb-Pb collisions (Lattice V4 baseline)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
IP
208Pb81+ (BFPP1)208Pb80+ (BFPP2)
206Pb82+ (EMD2)
207Pb82+ (EMD1)
M Schaumann Workshop on Ions at the FCC CERN
27
Smaller Z Ions ndash Impact on hadronic event count
20140922
bull Lower Z possibly higher available from injectors
bull Contribution of ultra-peripheral electromagnetic processes to the total cross-section would be reduced
Increased luminosity lifetime more particles available for hadronic interactions
Reduced secondary beam power emerging from collision point
bull Radiation damping rate does not change much for Zgt60o
o Lower Z beams would put more burn-off into hadronic events
o Worth considering small Z reduction from Pb to eg
(6--8)hadronic
BFPP EMD
hh tot
h
N Ldt N Z
Z
( )(Pb)L ZL
28
Heavy-Ion Beam Parameter Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
29
Heavy-Ion Luminosity Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
30
Future work neededbull Number of active experiments to be considered very carefully
1 or 2 bull Counter measures for (few kW) secondary beams from IPs
ndash Robust collimatorsabsorbers in dispersion suppressorsndash Shower calculations magnet quench risks etc
bull Include heavy ion beams in future evolution of injector chainndash Maximise no of ions injected in colliderndash Do we have to live with present limits in SPS
bull Extend LHC heavy-ion collimation studies to FCCndash Does synchrotron radiation damping solve this for us
bull Vacuum effects
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Collaboration welcome
31
Conclusions and Outlookbull With very conservative assumptions (past LHC Pb
beams) FCC-hh has clear potential for high luminosity nucleus-nucleus and proton-nucleus collisions
bull New highly efficient collider regime of strong radiation damping can be fully exploited with heavy-ion beams
bull Photon-photon and photonuclear processes create powerful secondary beams emerging from IPndash Foresee counter-measures from the start (cf LHC experience)
bull Extreme luminosity burn-off is a fact of nature ndash physics community might want to consider somewhat lower-Z species
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
32
BACKUP SLIDES
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
12
Effects on the Emittance ndash a new regime
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Intra-Beam Scattering (IBS) (Synchrotron) Radiation Damping
Emittance Growth Emittance Shrinkage
Growth rate dynamically changing with beam properties
Damping rate is constant for a given energy
IBS is weak for initial beam parameters but increases with decreasing emittance
Multiple small-angle Coulomb scattering within a charged particle beam
A charged particle radiates energy when itis accelerated ie bend on its circular orbit
Fast emittance decrease at the beginning of the fill until IBS becomes strong enough to counteract the radiation damping
Growth Times Unit FCC 50Z TeV
[h] 291
[h] 300
Damping Times Unit FCC 50Z TeV
[h] 024
[h] 049
13
BEAM AND LUMINOSITY EVOLUTION
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Pb-Pb
14
Pb-Pb Beam Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
bull Red tracking simulation taking into account IBS rad damping burn-off hellip
bull Black numerical solution of the ODE system on slide 7 using J Weirsquos analytical IBS formalism
rarr emittances and bunch length become very small
bull Green ddt = 0 artificial longitudinal blow-up to = 8cm
bull Blue artificial longitudinal and transverse blow-up to = 8cm and J Wei Evolution of Hadron Beams under Intrabeam
Scattering ConfProc C930517 (1993) 3651-3653 PAC 1993
Transverse Emittance
Bunch Length
Intensity
15
Pb-Pb Luminosity Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 0006 26
[Hzmb] 0017 73
[] 013 578
Summary for free beam evolution (no artificial blow-up)
If the beam dimensions become too small and artificial blow-up has to be used the luminosity will be affectedbull Peak Enhancement for long blow-up
since long and horizontal IBS are reduced due to larger rarr smaller
bull Reduced luminosity due to blown-up
16
Pb-Pb Average Luminosity
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
= time in collisions rarr to be optimised
= turn-around time = time dump rarr next collisions
Assumption (cycle time FCC without injections) (no injections from LHC)
Average Luminosity per hour
For free beam parameter evolution red case from previous slide
Max at
inst
17
Pb-Pb Integrated Luminosity per Run
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
bull Assumption
bull Consider more LHC injectionsrarr max (= FCC Length)rarr Dwell time at FCC inj plateau
rarr lengthen rarr Particle losses (amp emittance
growth)rarr Loss rate of Pb at injectionrarr Total beam intensity
rarr ltgt ltgt
Int Luminosity per run
Opt Time in Collisions
18
BEAM AND LUMINOSITY EVOLUTION
LHC has shown that p-Pb injecting and ramping with unequal revolution frequencies is feasible This will work for injection (provided we keep independent RF systems) and may not even be necessary in FCC ring
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
p-Pb
19
p-Pb Beam Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam Size Bunch Length
Intensity
Initial conditionsbull Pb-beam as for Pb-Pb operationbull Equal beam sizes σ for p and Pbbull Rad damping
rarr bull IBS scales with bull
rarr Fast Pb burn-off while const
20
p-Pb Luminosity Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 05 213
[Hzmb] 28 1192
[] 487 21068
Peak shifted to later timesrarr p shrinks slower than Pb
Luminosity decay slowerrarr constrarr 1e-Luminosity lifetime 14h
p-Pb Luminosity vs Turn-Around Time
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 201521
Max at
Int Luminosity per run
Opt Time in Collisions
For rarr Optimised fill length = 65h rarr ltgtrun 17 could give higher ltgtrun rarr But uncertainty on prediction
significantly enhanced rarr Early beam aborts and longer inj
times due to lost beams in the LHC reduce ltgtrun
rarr injection and fill times are both in the order of 10h
22
POTENTIAL LIMITATIONS
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
23
Beam-Beam Tune Shift
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam-Beam Parameter per Experiment
Unit LHC Designp-p
LHC DesignPb-Pb
FCCPb-Pb
FCCp-Pb
Initial [ 37 018 037 037
Peak [ 37 018 14 83
Beam-beam tune shift per experimentbull Beam m receives kick from Beam n bull uv =x y
The tune shift due to beam-beam interactions remains well below assumed limit for Pb-Pb but comes close to the limit for Pb in p-Pb collisions
Pb-Pb
p-Pb
γ-γ and γ-A processes in Pb-Pb collisions at FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015 24
2
208208 208
208208
20882 82 82
82 82 8
08208 82 208 82 82 20
20 20
8 8
8 2
8
0
1
7 82
B
BFPP2 Pb Pb Pb Pb 2e 10 mb
FPP1 Pb Pb Pb e 354 b 001235
EMD1 Pb Pb Pb n 20
00Pb
b
2
P
500
0
208208 82 8208 02 2 6 88 2 2
b 000485EMD2 Pb Pb P b 2n
35 b 000970Pb
Each of these makes a secondary beam emerging from the IP with rigidity change
Pb1 11 m mQ Q
Extensively discussed for LHC
Hadronic cross section is 8 b (so much less power in debris)
25
BFPP1 Beam Power in Pb-Pb for FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Countermeasures (eg DS collimators) have to be considered in initial lattice amp hardware design
FCC-PbPb
nominal LHC P 26Wrarr already expected to cause operational problems and poaaible long-term damage
41 PeV
BFPP1 Beam power 17 kW (peak)cP L E
26
Secondary beams from Pb-Pb collisions (Lattice V4 baseline)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
IP
208Pb81+ (BFPP1)208Pb80+ (BFPP2)
206Pb82+ (EMD2)
207Pb82+ (EMD1)
M Schaumann Workshop on Ions at the FCC CERN
27
Smaller Z Ions ndash Impact on hadronic event count
20140922
bull Lower Z possibly higher available from injectors
bull Contribution of ultra-peripheral electromagnetic processes to the total cross-section would be reduced
Increased luminosity lifetime more particles available for hadronic interactions
Reduced secondary beam power emerging from collision point
bull Radiation damping rate does not change much for Zgt60o
o Lower Z beams would put more burn-off into hadronic events
o Worth considering small Z reduction from Pb to eg
(6--8)hadronic
BFPP EMD
hh tot
h
N Ldt N Z
Z
( )(Pb)L ZL
28
Heavy-Ion Beam Parameter Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
29
Heavy-Ion Luminosity Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
30
Future work neededbull Number of active experiments to be considered very carefully
1 or 2 bull Counter measures for (few kW) secondary beams from IPs
ndash Robust collimatorsabsorbers in dispersion suppressorsndash Shower calculations magnet quench risks etc
bull Include heavy ion beams in future evolution of injector chainndash Maximise no of ions injected in colliderndash Do we have to live with present limits in SPS
bull Extend LHC heavy-ion collimation studies to FCCndash Does synchrotron radiation damping solve this for us
bull Vacuum effects
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Collaboration welcome
31
Conclusions and Outlookbull With very conservative assumptions (past LHC Pb
beams) FCC-hh has clear potential for high luminosity nucleus-nucleus and proton-nucleus collisions
bull New highly efficient collider regime of strong radiation damping can be fully exploited with heavy-ion beams
bull Photon-photon and photonuclear processes create powerful secondary beams emerging from IPndash Foresee counter-measures from the start (cf LHC experience)
bull Extreme luminosity burn-off is a fact of nature ndash physics community might want to consider somewhat lower-Z species
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
32
BACKUP SLIDES
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
13
BEAM AND LUMINOSITY EVOLUTION
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Pb-Pb
14
Pb-Pb Beam Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
bull Red tracking simulation taking into account IBS rad damping burn-off hellip
bull Black numerical solution of the ODE system on slide 7 using J Weirsquos analytical IBS formalism
rarr emittances and bunch length become very small
bull Green ddt = 0 artificial longitudinal blow-up to = 8cm
bull Blue artificial longitudinal and transverse blow-up to = 8cm and J Wei Evolution of Hadron Beams under Intrabeam
Scattering ConfProc C930517 (1993) 3651-3653 PAC 1993
Transverse Emittance
Bunch Length
Intensity
15
Pb-Pb Luminosity Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 0006 26
[Hzmb] 0017 73
[] 013 578
Summary for free beam evolution (no artificial blow-up)
If the beam dimensions become too small and artificial blow-up has to be used the luminosity will be affectedbull Peak Enhancement for long blow-up
since long and horizontal IBS are reduced due to larger rarr smaller
bull Reduced luminosity due to blown-up
16
Pb-Pb Average Luminosity
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
= time in collisions rarr to be optimised
= turn-around time = time dump rarr next collisions
Assumption (cycle time FCC without injections) (no injections from LHC)
Average Luminosity per hour
For free beam parameter evolution red case from previous slide
Max at
inst
17
Pb-Pb Integrated Luminosity per Run
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
bull Assumption
bull Consider more LHC injectionsrarr max (= FCC Length)rarr Dwell time at FCC inj plateau
rarr lengthen rarr Particle losses (amp emittance
growth)rarr Loss rate of Pb at injectionrarr Total beam intensity
rarr ltgt ltgt
Int Luminosity per run
Opt Time in Collisions
18
BEAM AND LUMINOSITY EVOLUTION
LHC has shown that p-Pb injecting and ramping with unequal revolution frequencies is feasible This will work for injection (provided we keep independent RF systems) and may not even be necessary in FCC ring
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
p-Pb
19
p-Pb Beam Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam Size Bunch Length
Intensity
Initial conditionsbull Pb-beam as for Pb-Pb operationbull Equal beam sizes σ for p and Pbbull Rad damping
rarr bull IBS scales with bull
rarr Fast Pb burn-off while const
20
p-Pb Luminosity Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 05 213
[Hzmb] 28 1192
[] 487 21068
Peak shifted to later timesrarr p shrinks slower than Pb
Luminosity decay slowerrarr constrarr 1e-Luminosity lifetime 14h
p-Pb Luminosity vs Turn-Around Time
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 201521
Max at
Int Luminosity per run
Opt Time in Collisions
For rarr Optimised fill length = 65h rarr ltgtrun 17 could give higher ltgtrun rarr But uncertainty on prediction
significantly enhanced rarr Early beam aborts and longer inj
times due to lost beams in the LHC reduce ltgtrun
rarr injection and fill times are both in the order of 10h
22
POTENTIAL LIMITATIONS
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
23
Beam-Beam Tune Shift
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam-Beam Parameter per Experiment
Unit LHC Designp-p
LHC DesignPb-Pb
FCCPb-Pb
FCCp-Pb
Initial [ 37 018 037 037
Peak [ 37 018 14 83
Beam-beam tune shift per experimentbull Beam m receives kick from Beam n bull uv =x y
The tune shift due to beam-beam interactions remains well below assumed limit for Pb-Pb but comes close to the limit for Pb in p-Pb collisions
Pb-Pb
p-Pb
γ-γ and γ-A processes in Pb-Pb collisions at FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015 24
2
208208 208
208208
20882 82 82
82 82 8
08208 82 208 82 82 20
20 20
8 8
8 2
8
0
1
7 82
B
BFPP2 Pb Pb Pb Pb 2e 10 mb
FPP1 Pb Pb Pb e 354 b 001235
EMD1 Pb Pb Pb n 20
00Pb
b
2
P
500
0
208208 82 8208 02 2 6 88 2 2
b 000485EMD2 Pb Pb P b 2n
35 b 000970Pb
Each of these makes a secondary beam emerging from the IP with rigidity change
Pb1 11 m mQ Q
Extensively discussed for LHC
Hadronic cross section is 8 b (so much less power in debris)
25
BFPP1 Beam Power in Pb-Pb for FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Countermeasures (eg DS collimators) have to be considered in initial lattice amp hardware design
FCC-PbPb
nominal LHC P 26Wrarr already expected to cause operational problems and poaaible long-term damage
41 PeV
BFPP1 Beam power 17 kW (peak)cP L E
26
Secondary beams from Pb-Pb collisions (Lattice V4 baseline)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
IP
208Pb81+ (BFPP1)208Pb80+ (BFPP2)
206Pb82+ (EMD2)
207Pb82+ (EMD1)
M Schaumann Workshop on Ions at the FCC CERN
27
Smaller Z Ions ndash Impact on hadronic event count
20140922
bull Lower Z possibly higher available from injectors
bull Contribution of ultra-peripheral electromagnetic processes to the total cross-section would be reduced
Increased luminosity lifetime more particles available for hadronic interactions
Reduced secondary beam power emerging from collision point
bull Radiation damping rate does not change much for Zgt60o
o Lower Z beams would put more burn-off into hadronic events
o Worth considering small Z reduction from Pb to eg
(6--8)hadronic
BFPP EMD
hh tot
h
N Ldt N Z
Z
( )(Pb)L ZL
28
Heavy-Ion Beam Parameter Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
29
Heavy-Ion Luminosity Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
30
Future work neededbull Number of active experiments to be considered very carefully
1 or 2 bull Counter measures for (few kW) secondary beams from IPs
ndash Robust collimatorsabsorbers in dispersion suppressorsndash Shower calculations magnet quench risks etc
bull Include heavy ion beams in future evolution of injector chainndash Maximise no of ions injected in colliderndash Do we have to live with present limits in SPS
bull Extend LHC heavy-ion collimation studies to FCCndash Does synchrotron radiation damping solve this for us
bull Vacuum effects
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Collaboration welcome
31
Conclusions and Outlookbull With very conservative assumptions (past LHC Pb
beams) FCC-hh has clear potential for high luminosity nucleus-nucleus and proton-nucleus collisions
bull New highly efficient collider regime of strong radiation damping can be fully exploited with heavy-ion beams
bull Photon-photon and photonuclear processes create powerful secondary beams emerging from IPndash Foresee counter-measures from the start (cf LHC experience)
bull Extreme luminosity burn-off is a fact of nature ndash physics community might want to consider somewhat lower-Z species
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
32
BACKUP SLIDES
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
14
Pb-Pb Beam Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
bull Red tracking simulation taking into account IBS rad damping burn-off hellip
bull Black numerical solution of the ODE system on slide 7 using J Weirsquos analytical IBS formalism
rarr emittances and bunch length become very small
bull Green ddt = 0 artificial longitudinal blow-up to = 8cm
bull Blue artificial longitudinal and transverse blow-up to = 8cm and J Wei Evolution of Hadron Beams under Intrabeam
Scattering ConfProc C930517 (1993) 3651-3653 PAC 1993
Transverse Emittance
Bunch Length
Intensity
15
Pb-Pb Luminosity Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 0006 26
[Hzmb] 0017 73
[] 013 578
Summary for free beam evolution (no artificial blow-up)
If the beam dimensions become too small and artificial blow-up has to be used the luminosity will be affectedbull Peak Enhancement for long blow-up
since long and horizontal IBS are reduced due to larger rarr smaller
bull Reduced luminosity due to blown-up
16
Pb-Pb Average Luminosity
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
= time in collisions rarr to be optimised
= turn-around time = time dump rarr next collisions
Assumption (cycle time FCC without injections) (no injections from LHC)
Average Luminosity per hour
For free beam parameter evolution red case from previous slide
Max at
inst
17
Pb-Pb Integrated Luminosity per Run
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
bull Assumption
bull Consider more LHC injectionsrarr max (= FCC Length)rarr Dwell time at FCC inj plateau
rarr lengthen rarr Particle losses (amp emittance
growth)rarr Loss rate of Pb at injectionrarr Total beam intensity
rarr ltgt ltgt
Int Luminosity per run
Opt Time in Collisions
18
BEAM AND LUMINOSITY EVOLUTION
LHC has shown that p-Pb injecting and ramping with unequal revolution frequencies is feasible This will work for injection (provided we keep independent RF systems) and may not even be necessary in FCC ring
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
p-Pb
19
p-Pb Beam Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam Size Bunch Length
Intensity
Initial conditionsbull Pb-beam as for Pb-Pb operationbull Equal beam sizes σ for p and Pbbull Rad damping
rarr bull IBS scales with bull
rarr Fast Pb burn-off while const
20
p-Pb Luminosity Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 05 213
[Hzmb] 28 1192
[] 487 21068
Peak shifted to later timesrarr p shrinks slower than Pb
Luminosity decay slowerrarr constrarr 1e-Luminosity lifetime 14h
p-Pb Luminosity vs Turn-Around Time
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 201521
Max at
Int Luminosity per run
Opt Time in Collisions
For rarr Optimised fill length = 65h rarr ltgtrun 17 could give higher ltgtrun rarr But uncertainty on prediction
significantly enhanced rarr Early beam aborts and longer inj
times due to lost beams in the LHC reduce ltgtrun
rarr injection and fill times are both in the order of 10h
22
POTENTIAL LIMITATIONS
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
23
Beam-Beam Tune Shift
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam-Beam Parameter per Experiment
Unit LHC Designp-p
LHC DesignPb-Pb
FCCPb-Pb
FCCp-Pb
Initial [ 37 018 037 037
Peak [ 37 018 14 83
Beam-beam tune shift per experimentbull Beam m receives kick from Beam n bull uv =x y
The tune shift due to beam-beam interactions remains well below assumed limit for Pb-Pb but comes close to the limit for Pb in p-Pb collisions
Pb-Pb
p-Pb
γ-γ and γ-A processes in Pb-Pb collisions at FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015 24
2
208208 208
208208
20882 82 82
82 82 8
08208 82 208 82 82 20
20 20
8 8
8 2
8
0
1
7 82
B
BFPP2 Pb Pb Pb Pb 2e 10 mb
FPP1 Pb Pb Pb e 354 b 001235
EMD1 Pb Pb Pb n 20
00Pb
b
2
P
500
0
208208 82 8208 02 2 6 88 2 2
b 000485EMD2 Pb Pb P b 2n
35 b 000970Pb
Each of these makes a secondary beam emerging from the IP with rigidity change
Pb1 11 m mQ Q
Extensively discussed for LHC
Hadronic cross section is 8 b (so much less power in debris)
25
BFPP1 Beam Power in Pb-Pb for FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Countermeasures (eg DS collimators) have to be considered in initial lattice amp hardware design
FCC-PbPb
nominal LHC P 26Wrarr already expected to cause operational problems and poaaible long-term damage
41 PeV
BFPP1 Beam power 17 kW (peak)cP L E
26
Secondary beams from Pb-Pb collisions (Lattice V4 baseline)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
IP
208Pb81+ (BFPP1)208Pb80+ (BFPP2)
206Pb82+ (EMD2)
207Pb82+ (EMD1)
M Schaumann Workshop on Ions at the FCC CERN
27
Smaller Z Ions ndash Impact on hadronic event count
20140922
bull Lower Z possibly higher available from injectors
bull Contribution of ultra-peripheral electromagnetic processes to the total cross-section would be reduced
Increased luminosity lifetime more particles available for hadronic interactions
Reduced secondary beam power emerging from collision point
bull Radiation damping rate does not change much for Zgt60o
o Lower Z beams would put more burn-off into hadronic events
o Worth considering small Z reduction from Pb to eg
(6--8)hadronic
BFPP EMD
hh tot
h
N Ldt N Z
Z
( )(Pb)L ZL
28
Heavy-Ion Beam Parameter Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
29
Heavy-Ion Luminosity Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
30
Future work neededbull Number of active experiments to be considered very carefully
1 or 2 bull Counter measures for (few kW) secondary beams from IPs
ndash Robust collimatorsabsorbers in dispersion suppressorsndash Shower calculations magnet quench risks etc
bull Include heavy ion beams in future evolution of injector chainndash Maximise no of ions injected in colliderndash Do we have to live with present limits in SPS
bull Extend LHC heavy-ion collimation studies to FCCndash Does synchrotron radiation damping solve this for us
bull Vacuum effects
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Collaboration welcome
31
Conclusions and Outlookbull With very conservative assumptions (past LHC Pb
beams) FCC-hh has clear potential for high luminosity nucleus-nucleus and proton-nucleus collisions
bull New highly efficient collider regime of strong radiation damping can be fully exploited with heavy-ion beams
bull Photon-photon and photonuclear processes create powerful secondary beams emerging from IPndash Foresee counter-measures from the start (cf LHC experience)
bull Extreme luminosity burn-off is a fact of nature ndash physics community might want to consider somewhat lower-Z species
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
32
BACKUP SLIDES
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
15
Pb-Pb Luminosity Evolution
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 0006 26
[Hzmb] 0017 73
[] 013 578
Summary for free beam evolution (no artificial blow-up)
If the beam dimensions become too small and artificial blow-up has to be used the luminosity will be affectedbull Peak Enhancement for long blow-up
since long and horizontal IBS are reduced due to larger rarr smaller
bull Reduced luminosity due to blown-up
16
Pb-Pb Average Luminosity
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
= time in collisions rarr to be optimised
= turn-around time = time dump rarr next collisions
Assumption (cycle time FCC without injections) (no injections from LHC)
Average Luminosity per hour
For free beam parameter evolution red case from previous slide
Max at
inst
17
Pb-Pb Integrated Luminosity per Run
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
bull Assumption
bull Consider more LHC injectionsrarr max (= FCC Length)rarr Dwell time at FCC inj plateau
rarr lengthen rarr Particle losses (amp emittance
growth)rarr Loss rate of Pb at injectionrarr Total beam intensity
rarr ltgt ltgt
Int Luminosity per run
Opt Time in Collisions
18
BEAM AND LUMINOSITY EVOLUTION
LHC has shown that p-Pb injecting and ramping with unequal revolution frequencies is feasible This will work for injection (provided we keep independent RF systems) and may not even be necessary in FCC ring
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
p-Pb
19
p-Pb Beam Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam Size Bunch Length
Intensity
Initial conditionsbull Pb-beam as for Pb-Pb operationbull Equal beam sizes σ for p and Pbbull Rad damping
rarr bull IBS scales with bull
rarr Fast Pb burn-off while const
20
p-Pb Luminosity Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 05 213
[Hzmb] 28 1192
[] 487 21068
Peak shifted to later timesrarr p shrinks slower than Pb
Luminosity decay slowerrarr constrarr 1e-Luminosity lifetime 14h
p-Pb Luminosity vs Turn-Around Time
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 201521
Max at
Int Luminosity per run
Opt Time in Collisions
For rarr Optimised fill length = 65h rarr ltgtrun 17 could give higher ltgtrun rarr But uncertainty on prediction
significantly enhanced rarr Early beam aborts and longer inj
times due to lost beams in the LHC reduce ltgtrun
rarr injection and fill times are both in the order of 10h
22
POTENTIAL LIMITATIONS
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
23
Beam-Beam Tune Shift
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam-Beam Parameter per Experiment
Unit LHC Designp-p
LHC DesignPb-Pb
FCCPb-Pb
FCCp-Pb
Initial [ 37 018 037 037
Peak [ 37 018 14 83
Beam-beam tune shift per experimentbull Beam m receives kick from Beam n bull uv =x y
The tune shift due to beam-beam interactions remains well below assumed limit for Pb-Pb but comes close to the limit for Pb in p-Pb collisions
Pb-Pb
p-Pb
γ-γ and γ-A processes in Pb-Pb collisions at FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015 24
2
208208 208
208208
20882 82 82
82 82 8
08208 82 208 82 82 20
20 20
8 8
8 2
8
0
1
7 82
B
BFPP2 Pb Pb Pb Pb 2e 10 mb
FPP1 Pb Pb Pb e 354 b 001235
EMD1 Pb Pb Pb n 20
00Pb
b
2
P
500
0
208208 82 8208 02 2 6 88 2 2
b 000485EMD2 Pb Pb P b 2n
35 b 000970Pb
Each of these makes a secondary beam emerging from the IP with rigidity change
Pb1 11 m mQ Q
Extensively discussed for LHC
Hadronic cross section is 8 b (so much less power in debris)
25
BFPP1 Beam Power in Pb-Pb for FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Countermeasures (eg DS collimators) have to be considered in initial lattice amp hardware design
FCC-PbPb
nominal LHC P 26Wrarr already expected to cause operational problems and poaaible long-term damage
41 PeV
BFPP1 Beam power 17 kW (peak)cP L E
26
Secondary beams from Pb-Pb collisions (Lattice V4 baseline)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
IP
208Pb81+ (BFPP1)208Pb80+ (BFPP2)
206Pb82+ (EMD2)
207Pb82+ (EMD1)
M Schaumann Workshop on Ions at the FCC CERN
27
Smaller Z Ions ndash Impact on hadronic event count
20140922
bull Lower Z possibly higher available from injectors
bull Contribution of ultra-peripheral electromagnetic processes to the total cross-section would be reduced
Increased luminosity lifetime more particles available for hadronic interactions
Reduced secondary beam power emerging from collision point
bull Radiation damping rate does not change much for Zgt60o
o Lower Z beams would put more burn-off into hadronic events
o Worth considering small Z reduction from Pb to eg
(6--8)hadronic
BFPP EMD
hh tot
h
N Ldt N Z
Z
( )(Pb)L ZL
28
Heavy-Ion Beam Parameter Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
29
Heavy-Ion Luminosity Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
30
Future work neededbull Number of active experiments to be considered very carefully
1 or 2 bull Counter measures for (few kW) secondary beams from IPs
ndash Robust collimatorsabsorbers in dispersion suppressorsndash Shower calculations magnet quench risks etc
bull Include heavy ion beams in future evolution of injector chainndash Maximise no of ions injected in colliderndash Do we have to live with present limits in SPS
bull Extend LHC heavy-ion collimation studies to FCCndash Does synchrotron radiation damping solve this for us
bull Vacuum effects
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Collaboration welcome
31
Conclusions and Outlookbull With very conservative assumptions (past LHC Pb
beams) FCC-hh has clear potential for high luminosity nucleus-nucleus and proton-nucleus collisions
bull New highly efficient collider regime of strong radiation damping can be fully exploited with heavy-ion beams
bull Photon-photon and photonuclear processes create powerful secondary beams emerging from IPndash Foresee counter-measures from the start (cf LHC experience)
bull Extreme luminosity burn-off is a fact of nature ndash physics community might want to consider somewhat lower-Z species
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
32
BACKUP SLIDES
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
16
Pb-Pb Average Luminosity
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
= time in collisions rarr to be optimised
= turn-around time = time dump rarr next collisions
Assumption (cycle time FCC without injections) (no injections from LHC)
Average Luminosity per hour
For free beam parameter evolution red case from previous slide
Max at
inst
17
Pb-Pb Integrated Luminosity per Run
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
bull Assumption
bull Consider more LHC injectionsrarr max (= FCC Length)rarr Dwell time at FCC inj plateau
rarr lengthen rarr Particle losses (amp emittance
growth)rarr Loss rate of Pb at injectionrarr Total beam intensity
rarr ltgt ltgt
Int Luminosity per run
Opt Time in Collisions
18
BEAM AND LUMINOSITY EVOLUTION
LHC has shown that p-Pb injecting and ramping with unequal revolution frequencies is feasible This will work for injection (provided we keep independent RF systems) and may not even be necessary in FCC ring
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
p-Pb
19
p-Pb Beam Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam Size Bunch Length
Intensity
Initial conditionsbull Pb-beam as for Pb-Pb operationbull Equal beam sizes σ for p and Pbbull Rad damping
rarr bull IBS scales with bull
rarr Fast Pb burn-off while const
20
p-Pb Luminosity Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 05 213
[Hzmb] 28 1192
[] 487 21068
Peak shifted to later timesrarr p shrinks slower than Pb
Luminosity decay slowerrarr constrarr 1e-Luminosity lifetime 14h
p-Pb Luminosity vs Turn-Around Time
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 201521
Max at
Int Luminosity per run
Opt Time in Collisions
For rarr Optimised fill length = 65h rarr ltgtrun 17 could give higher ltgtrun rarr But uncertainty on prediction
significantly enhanced rarr Early beam aborts and longer inj
times due to lost beams in the LHC reduce ltgtrun
rarr injection and fill times are both in the order of 10h
22
POTENTIAL LIMITATIONS
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
23
Beam-Beam Tune Shift
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam-Beam Parameter per Experiment
Unit LHC Designp-p
LHC DesignPb-Pb
FCCPb-Pb
FCCp-Pb
Initial [ 37 018 037 037
Peak [ 37 018 14 83
Beam-beam tune shift per experimentbull Beam m receives kick from Beam n bull uv =x y
The tune shift due to beam-beam interactions remains well below assumed limit for Pb-Pb but comes close to the limit for Pb in p-Pb collisions
Pb-Pb
p-Pb
γ-γ and γ-A processes in Pb-Pb collisions at FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015 24
2
208208 208
208208
20882 82 82
82 82 8
08208 82 208 82 82 20
20 20
8 8
8 2
8
0
1
7 82
B
BFPP2 Pb Pb Pb Pb 2e 10 mb
FPP1 Pb Pb Pb e 354 b 001235
EMD1 Pb Pb Pb n 20
00Pb
b
2
P
500
0
208208 82 8208 02 2 6 88 2 2
b 000485EMD2 Pb Pb P b 2n
35 b 000970Pb
Each of these makes a secondary beam emerging from the IP with rigidity change
Pb1 11 m mQ Q
Extensively discussed for LHC
Hadronic cross section is 8 b (so much less power in debris)
25
BFPP1 Beam Power in Pb-Pb for FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Countermeasures (eg DS collimators) have to be considered in initial lattice amp hardware design
FCC-PbPb
nominal LHC P 26Wrarr already expected to cause operational problems and poaaible long-term damage
41 PeV
BFPP1 Beam power 17 kW (peak)cP L E
26
Secondary beams from Pb-Pb collisions (Lattice V4 baseline)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
IP
208Pb81+ (BFPP1)208Pb80+ (BFPP2)
206Pb82+ (EMD2)
207Pb82+ (EMD1)
M Schaumann Workshop on Ions at the FCC CERN
27
Smaller Z Ions ndash Impact on hadronic event count
20140922
bull Lower Z possibly higher available from injectors
bull Contribution of ultra-peripheral electromagnetic processes to the total cross-section would be reduced
Increased luminosity lifetime more particles available for hadronic interactions
Reduced secondary beam power emerging from collision point
bull Radiation damping rate does not change much for Zgt60o
o Lower Z beams would put more burn-off into hadronic events
o Worth considering small Z reduction from Pb to eg
(6--8)hadronic
BFPP EMD
hh tot
h
N Ldt N Z
Z
( )(Pb)L ZL
28
Heavy-Ion Beam Parameter Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
29
Heavy-Ion Luminosity Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
30
Future work neededbull Number of active experiments to be considered very carefully
1 or 2 bull Counter measures for (few kW) secondary beams from IPs
ndash Robust collimatorsabsorbers in dispersion suppressorsndash Shower calculations magnet quench risks etc
bull Include heavy ion beams in future evolution of injector chainndash Maximise no of ions injected in colliderndash Do we have to live with present limits in SPS
bull Extend LHC heavy-ion collimation studies to FCCndash Does synchrotron radiation damping solve this for us
bull Vacuum effects
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Collaboration welcome
31
Conclusions and Outlookbull With very conservative assumptions (past LHC Pb
beams) FCC-hh has clear potential for high luminosity nucleus-nucleus and proton-nucleus collisions
bull New highly efficient collider regime of strong radiation damping can be fully exploited with heavy-ion beams
bull Photon-photon and photonuclear processes create powerful secondary beams emerging from IPndash Foresee counter-measures from the start (cf LHC experience)
bull Extreme luminosity burn-off is a fact of nature ndash physics community might want to consider somewhat lower-Z species
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
32
BACKUP SLIDES
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
17
Pb-Pb Integrated Luminosity per Run
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
bull Assumption
bull Consider more LHC injectionsrarr max (= FCC Length)rarr Dwell time at FCC inj plateau
rarr lengthen rarr Particle losses (amp emittance
growth)rarr Loss rate of Pb at injectionrarr Total beam intensity
rarr ltgt ltgt
Int Luminosity per run
Opt Time in Collisions
18
BEAM AND LUMINOSITY EVOLUTION
LHC has shown that p-Pb injecting and ramping with unequal revolution frequencies is feasible This will work for injection (provided we keep independent RF systems) and may not even be necessary in FCC ring
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
p-Pb
19
p-Pb Beam Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam Size Bunch Length
Intensity
Initial conditionsbull Pb-beam as for Pb-Pb operationbull Equal beam sizes σ for p and Pbbull Rad damping
rarr bull IBS scales with bull
rarr Fast Pb burn-off while const
20
p-Pb Luminosity Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 05 213
[Hzmb] 28 1192
[] 487 21068
Peak shifted to later timesrarr p shrinks slower than Pb
Luminosity decay slowerrarr constrarr 1e-Luminosity lifetime 14h
p-Pb Luminosity vs Turn-Around Time
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 201521
Max at
Int Luminosity per run
Opt Time in Collisions
For rarr Optimised fill length = 65h rarr ltgtrun 17 could give higher ltgtrun rarr But uncertainty on prediction
significantly enhanced rarr Early beam aborts and longer inj
times due to lost beams in the LHC reduce ltgtrun
rarr injection and fill times are both in the order of 10h
22
POTENTIAL LIMITATIONS
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
23
Beam-Beam Tune Shift
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam-Beam Parameter per Experiment
Unit LHC Designp-p
LHC DesignPb-Pb
FCCPb-Pb
FCCp-Pb
Initial [ 37 018 037 037
Peak [ 37 018 14 83
Beam-beam tune shift per experimentbull Beam m receives kick from Beam n bull uv =x y
The tune shift due to beam-beam interactions remains well below assumed limit for Pb-Pb but comes close to the limit for Pb in p-Pb collisions
Pb-Pb
p-Pb
γ-γ and γ-A processes in Pb-Pb collisions at FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015 24
2
208208 208
208208
20882 82 82
82 82 8
08208 82 208 82 82 20
20 20
8 8
8 2
8
0
1
7 82
B
BFPP2 Pb Pb Pb Pb 2e 10 mb
FPP1 Pb Pb Pb e 354 b 001235
EMD1 Pb Pb Pb n 20
00Pb
b
2
P
500
0
208208 82 8208 02 2 6 88 2 2
b 000485EMD2 Pb Pb P b 2n
35 b 000970Pb
Each of these makes a secondary beam emerging from the IP with rigidity change
Pb1 11 m mQ Q
Extensively discussed for LHC
Hadronic cross section is 8 b (so much less power in debris)
25
BFPP1 Beam Power in Pb-Pb for FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Countermeasures (eg DS collimators) have to be considered in initial lattice amp hardware design
FCC-PbPb
nominal LHC P 26Wrarr already expected to cause operational problems and poaaible long-term damage
41 PeV
BFPP1 Beam power 17 kW (peak)cP L E
26
Secondary beams from Pb-Pb collisions (Lattice V4 baseline)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
IP
208Pb81+ (BFPP1)208Pb80+ (BFPP2)
206Pb82+ (EMD2)
207Pb82+ (EMD1)
M Schaumann Workshop on Ions at the FCC CERN
27
Smaller Z Ions ndash Impact on hadronic event count
20140922
bull Lower Z possibly higher available from injectors
bull Contribution of ultra-peripheral electromagnetic processes to the total cross-section would be reduced
Increased luminosity lifetime more particles available for hadronic interactions
Reduced secondary beam power emerging from collision point
bull Radiation damping rate does not change much for Zgt60o
o Lower Z beams would put more burn-off into hadronic events
o Worth considering small Z reduction from Pb to eg
(6--8)hadronic
BFPP EMD
hh tot
h
N Ldt N Z
Z
( )(Pb)L ZL
28
Heavy-Ion Beam Parameter Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
29
Heavy-Ion Luminosity Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
30
Future work neededbull Number of active experiments to be considered very carefully
1 or 2 bull Counter measures for (few kW) secondary beams from IPs
ndash Robust collimatorsabsorbers in dispersion suppressorsndash Shower calculations magnet quench risks etc
bull Include heavy ion beams in future evolution of injector chainndash Maximise no of ions injected in colliderndash Do we have to live with present limits in SPS
bull Extend LHC heavy-ion collimation studies to FCCndash Does synchrotron radiation damping solve this for us
bull Vacuum effects
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Collaboration welcome
31
Conclusions and Outlookbull With very conservative assumptions (past LHC Pb
beams) FCC-hh has clear potential for high luminosity nucleus-nucleus and proton-nucleus collisions
bull New highly efficient collider regime of strong radiation damping can be fully exploited with heavy-ion beams
bull Photon-photon and photonuclear processes create powerful secondary beams emerging from IPndash Foresee counter-measures from the start (cf LHC experience)
bull Extreme luminosity burn-off is a fact of nature ndash physics community might want to consider somewhat lower-Z species
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
32
BACKUP SLIDES
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
18
BEAM AND LUMINOSITY EVOLUTION
LHC has shown that p-Pb injecting and ramping with unequal revolution frequencies is feasible This will work for injection (provided we keep independent RF systems) and may not even be necessary in FCC ring
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
p-Pb
19
p-Pb Beam Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam Size Bunch Length
Intensity
Initial conditionsbull Pb-beam as for Pb-Pb operationbull Equal beam sizes σ for p and Pbbull Rad damping
rarr bull IBS scales with bull
rarr Fast Pb burn-off while const
20
p-Pb Luminosity Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 05 213
[Hzmb] 28 1192
[] 487 21068
Peak shifted to later timesrarr p shrinks slower than Pb
Luminosity decay slowerrarr constrarr 1e-Luminosity lifetime 14h
p-Pb Luminosity vs Turn-Around Time
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 201521
Max at
Int Luminosity per run
Opt Time in Collisions
For rarr Optimised fill length = 65h rarr ltgtrun 17 could give higher ltgtrun rarr But uncertainty on prediction
significantly enhanced rarr Early beam aborts and longer inj
times due to lost beams in the LHC reduce ltgtrun
rarr injection and fill times are both in the order of 10h
22
POTENTIAL LIMITATIONS
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
23
Beam-Beam Tune Shift
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam-Beam Parameter per Experiment
Unit LHC Designp-p
LHC DesignPb-Pb
FCCPb-Pb
FCCp-Pb
Initial [ 37 018 037 037
Peak [ 37 018 14 83
Beam-beam tune shift per experimentbull Beam m receives kick from Beam n bull uv =x y
The tune shift due to beam-beam interactions remains well below assumed limit for Pb-Pb but comes close to the limit for Pb in p-Pb collisions
Pb-Pb
p-Pb
γ-γ and γ-A processes in Pb-Pb collisions at FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015 24
2
208208 208
208208
20882 82 82
82 82 8
08208 82 208 82 82 20
20 20
8 8
8 2
8
0
1
7 82
B
BFPP2 Pb Pb Pb Pb 2e 10 mb
FPP1 Pb Pb Pb e 354 b 001235
EMD1 Pb Pb Pb n 20
00Pb
b
2
P
500
0
208208 82 8208 02 2 6 88 2 2
b 000485EMD2 Pb Pb P b 2n
35 b 000970Pb
Each of these makes a secondary beam emerging from the IP with rigidity change
Pb1 11 m mQ Q
Extensively discussed for LHC
Hadronic cross section is 8 b (so much less power in debris)
25
BFPP1 Beam Power in Pb-Pb for FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Countermeasures (eg DS collimators) have to be considered in initial lattice amp hardware design
FCC-PbPb
nominal LHC P 26Wrarr already expected to cause operational problems and poaaible long-term damage
41 PeV
BFPP1 Beam power 17 kW (peak)cP L E
26
Secondary beams from Pb-Pb collisions (Lattice V4 baseline)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
IP
208Pb81+ (BFPP1)208Pb80+ (BFPP2)
206Pb82+ (EMD2)
207Pb82+ (EMD1)
M Schaumann Workshop on Ions at the FCC CERN
27
Smaller Z Ions ndash Impact on hadronic event count
20140922
bull Lower Z possibly higher available from injectors
bull Contribution of ultra-peripheral electromagnetic processes to the total cross-section would be reduced
Increased luminosity lifetime more particles available for hadronic interactions
Reduced secondary beam power emerging from collision point
bull Radiation damping rate does not change much for Zgt60o
o Lower Z beams would put more burn-off into hadronic events
o Worth considering small Z reduction from Pb to eg
(6--8)hadronic
BFPP EMD
hh tot
h
N Ldt N Z
Z
( )(Pb)L ZL
28
Heavy-Ion Beam Parameter Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
29
Heavy-Ion Luminosity Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
30
Future work neededbull Number of active experiments to be considered very carefully
1 or 2 bull Counter measures for (few kW) secondary beams from IPs
ndash Robust collimatorsabsorbers in dispersion suppressorsndash Shower calculations magnet quench risks etc
bull Include heavy ion beams in future evolution of injector chainndash Maximise no of ions injected in colliderndash Do we have to live with present limits in SPS
bull Extend LHC heavy-ion collimation studies to FCCndash Does synchrotron radiation damping solve this for us
bull Vacuum effects
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Collaboration welcome
31
Conclusions and Outlookbull With very conservative assumptions (past LHC Pb
beams) FCC-hh has clear potential for high luminosity nucleus-nucleus and proton-nucleus collisions
bull New highly efficient collider regime of strong radiation damping can be fully exploited with heavy-ion beams
bull Photon-photon and photonuclear processes create powerful secondary beams emerging from IPndash Foresee counter-measures from the start (cf LHC experience)
bull Extreme luminosity burn-off is a fact of nature ndash physics community might want to consider somewhat lower-Z species
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
32
BACKUP SLIDES
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
19
p-Pb Beam Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam Size Bunch Length
Intensity
Initial conditionsbull Pb-beam as for Pb-Pb operationbull Equal beam sizes σ for p and Pbbull Rad damping
rarr bull IBS scales with bull
rarr Fast Pb burn-off while const
20
p-Pb Luminosity Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 05 213
[Hzmb] 28 1192
[] 487 21068
Peak shifted to later timesrarr p shrinks slower than Pb
Luminosity decay slowerrarr constrarr 1e-Luminosity lifetime 14h
p-Pb Luminosity vs Turn-Around Time
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 201521
Max at
Int Luminosity per run
Opt Time in Collisions
For rarr Optimised fill length = 65h rarr ltgtrun 17 could give higher ltgtrun rarr But uncertainty on prediction
significantly enhanced rarr Early beam aborts and longer inj
times due to lost beams in the LHC reduce ltgtrun
rarr injection and fill times are both in the order of 10h
22
POTENTIAL LIMITATIONS
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
23
Beam-Beam Tune Shift
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam-Beam Parameter per Experiment
Unit LHC Designp-p
LHC DesignPb-Pb
FCCPb-Pb
FCCp-Pb
Initial [ 37 018 037 037
Peak [ 37 018 14 83
Beam-beam tune shift per experimentbull Beam m receives kick from Beam n bull uv =x y
The tune shift due to beam-beam interactions remains well below assumed limit for Pb-Pb but comes close to the limit for Pb in p-Pb collisions
Pb-Pb
p-Pb
γ-γ and γ-A processes in Pb-Pb collisions at FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015 24
2
208208 208
208208
20882 82 82
82 82 8
08208 82 208 82 82 20
20 20
8 8
8 2
8
0
1
7 82
B
BFPP2 Pb Pb Pb Pb 2e 10 mb
FPP1 Pb Pb Pb e 354 b 001235
EMD1 Pb Pb Pb n 20
00Pb
b
2
P
500
0
208208 82 8208 02 2 6 88 2 2
b 000485EMD2 Pb Pb P b 2n
35 b 000970Pb
Each of these makes a secondary beam emerging from the IP with rigidity change
Pb1 11 m mQ Q
Extensively discussed for LHC
Hadronic cross section is 8 b (so much less power in debris)
25
BFPP1 Beam Power in Pb-Pb for FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Countermeasures (eg DS collimators) have to be considered in initial lattice amp hardware design
FCC-PbPb
nominal LHC P 26Wrarr already expected to cause operational problems and poaaible long-term damage
41 PeV
BFPP1 Beam power 17 kW (peak)cP L E
26
Secondary beams from Pb-Pb collisions (Lattice V4 baseline)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
IP
208Pb81+ (BFPP1)208Pb80+ (BFPP2)
206Pb82+ (EMD2)
207Pb82+ (EMD1)
M Schaumann Workshop on Ions at the FCC CERN
27
Smaller Z Ions ndash Impact on hadronic event count
20140922
bull Lower Z possibly higher available from injectors
bull Contribution of ultra-peripheral electromagnetic processes to the total cross-section would be reduced
Increased luminosity lifetime more particles available for hadronic interactions
Reduced secondary beam power emerging from collision point
bull Radiation damping rate does not change much for Zgt60o
o Lower Z beams would put more burn-off into hadronic events
o Worth considering small Z reduction from Pb to eg
(6--8)hadronic
BFPP EMD
hh tot
h
N Ldt N Z
Z
( )(Pb)L ZL
28
Heavy-Ion Beam Parameter Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
29
Heavy-Ion Luminosity Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
30
Future work neededbull Number of active experiments to be considered very carefully
1 or 2 bull Counter measures for (few kW) secondary beams from IPs
ndash Robust collimatorsabsorbers in dispersion suppressorsndash Shower calculations magnet quench risks etc
bull Include heavy ion beams in future evolution of injector chainndash Maximise no of ions injected in colliderndash Do we have to live with present limits in SPS
bull Extend LHC heavy-ion collimation studies to FCCndash Does synchrotron radiation damping solve this for us
bull Vacuum effects
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Collaboration welcome
31
Conclusions and Outlookbull With very conservative assumptions (past LHC Pb
beams) FCC-hh has clear potential for high luminosity nucleus-nucleus and proton-nucleus collisions
bull New highly efficient collider regime of strong radiation damping can be fully exploited with heavy-ion beams
bull Photon-photon and photonuclear processes create powerful secondary beams emerging from IPndash Foresee counter-measures from the start (cf LHC experience)
bull Extreme luminosity burn-off is a fact of nature ndash physics community might want to consider somewhat lower-Z species
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
32
BACKUP SLIDES
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
20
p-Pb Luminosity Evolution (1 Experiment)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Unit per Bunch whole Beam
[Hzmb] 05 213
[Hzmb] 28 1192
[] 487 21068
Peak shifted to later timesrarr p shrinks slower than Pb
Luminosity decay slowerrarr constrarr 1e-Luminosity lifetime 14h
p-Pb Luminosity vs Turn-Around Time
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 201521
Max at
Int Luminosity per run
Opt Time in Collisions
For rarr Optimised fill length = 65h rarr ltgtrun 17 could give higher ltgtrun rarr But uncertainty on prediction
significantly enhanced rarr Early beam aborts and longer inj
times due to lost beams in the LHC reduce ltgtrun
rarr injection and fill times are both in the order of 10h
22
POTENTIAL LIMITATIONS
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
23
Beam-Beam Tune Shift
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam-Beam Parameter per Experiment
Unit LHC Designp-p
LHC DesignPb-Pb
FCCPb-Pb
FCCp-Pb
Initial [ 37 018 037 037
Peak [ 37 018 14 83
Beam-beam tune shift per experimentbull Beam m receives kick from Beam n bull uv =x y
The tune shift due to beam-beam interactions remains well below assumed limit for Pb-Pb but comes close to the limit for Pb in p-Pb collisions
Pb-Pb
p-Pb
γ-γ and γ-A processes in Pb-Pb collisions at FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015 24
2
208208 208
208208
20882 82 82
82 82 8
08208 82 208 82 82 20
20 20
8 8
8 2
8
0
1
7 82
B
BFPP2 Pb Pb Pb Pb 2e 10 mb
FPP1 Pb Pb Pb e 354 b 001235
EMD1 Pb Pb Pb n 20
00Pb
b
2
P
500
0
208208 82 8208 02 2 6 88 2 2
b 000485EMD2 Pb Pb P b 2n
35 b 000970Pb
Each of these makes a secondary beam emerging from the IP with rigidity change
Pb1 11 m mQ Q
Extensively discussed for LHC
Hadronic cross section is 8 b (so much less power in debris)
25
BFPP1 Beam Power in Pb-Pb for FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Countermeasures (eg DS collimators) have to be considered in initial lattice amp hardware design
FCC-PbPb
nominal LHC P 26Wrarr already expected to cause operational problems and poaaible long-term damage
41 PeV
BFPP1 Beam power 17 kW (peak)cP L E
26
Secondary beams from Pb-Pb collisions (Lattice V4 baseline)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
IP
208Pb81+ (BFPP1)208Pb80+ (BFPP2)
206Pb82+ (EMD2)
207Pb82+ (EMD1)
M Schaumann Workshop on Ions at the FCC CERN
27
Smaller Z Ions ndash Impact on hadronic event count
20140922
bull Lower Z possibly higher available from injectors
bull Contribution of ultra-peripheral electromagnetic processes to the total cross-section would be reduced
Increased luminosity lifetime more particles available for hadronic interactions
Reduced secondary beam power emerging from collision point
bull Radiation damping rate does not change much for Zgt60o
o Lower Z beams would put more burn-off into hadronic events
o Worth considering small Z reduction from Pb to eg
(6--8)hadronic
BFPP EMD
hh tot
h
N Ldt N Z
Z
( )(Pb)L ZL
28
Heavy-Ion Beam Parameter Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
29
Heavy-Ion Luminosity Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
30
Future work neededbull Number of active experiments to be considered very carefully
1 or 2 bull Counter measures for (few kW) secondary beams from IPs
ndash Robust collimatorsabsorbers in dispersion suppressorsndash Shower calculations magnet quench risks etc
bull Include heavy ion beams in future evolution of injector chainndash Maximise no of ions injected in colliderndash Do we have to live with present limits in SPS
bull Extend LHC heavy-ion collimation studies to FCCndash Does synchrotron radiation damping solve this for us
bull Vacuum effects
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Collaboration welcome
31
Conclusions and Outlookbull With very conservative assumptions (past LHC Pb
beams) FCC-hh has clear potential for high luminosity nucleus-nucleus and proton-nucleus collisions
bull New highly efficient collider regime of strong radiation damping can be fully exploited with heavy-ion beams
bull Photon-photon and photonuclear processes create powerful secondary beams emerging from IPndash Foresee counter-measures from the start (cf LHC experience)
bull Extreme luminosity burn-off is a fact of nature ndash physics community might want to consider somewhat lower-Z species
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
32
BACKUP SLIDES
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
p-Pb Luminosity vs Turn-Around Time
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 201521
Max at
Int Luminosity per run
Opt Time in Collisions
For rarr Optimised fill length = 65h rarr ltgtrun 17 could give higher ltgtrun rarr But uncertainty on prediction
significantly enhanced rarr Early beam aborts and longer inj
times due to lost beams in the LHC reduce ltgtrun
rarr injection and fill times are both in the order of 10h
22
POTENTIAL LIMITATIONS
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
23
Beam-Beam Tune Shift
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam-Beam Parameter per Experiment
Unit LHC Designp-p
LHC DesignPb-Pb
FCCPb-Pb
FCCp-Pb
Initial [ 37 018 037 037
Peak [ 37 018 14 83
Beam-beam tune shift per experimentbull Beam m receives kick from Beam n bull uv =x y
The tune shift due to beam-beam interactions remains well below assumed limit for Pb-Pb but comes close to the limit for Pb in p-Pb collisions
Pb-Pb
p-Pb
γ-γ and γ-A processes in Pb-Pb collisions at FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015 24
2
208208 208
208208
20882 82 82
82 82 8
08208 82 208 82 82 20
20 20
8 8
8 2
8
0
1
7 82
B
BFPP2 Pb Pb Pb Pb 2e 10 mb
FPP1 Pb Pb Pb e 354 b 001235
EMD1 Pb Pb Pb n 20
00Pb
b
2
P
500
0
208208 82 8208 02 2 6 88 2 2
b 000485EMD2 Pb Pb P b 2n
35 b 000970Pb
Each of these makes a secondary beam emerging from the IP with rigidity change
Pb1 11 m mQ Q
Extensively discussed for LHC
Hadronic cross section is 8 b (so much less power in debris)
25
BFPP1 Beam Power in Pb-Pb for FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Countermeasures (eg DS collimators) have to be considered in initial lattice amp hardware design
FCC-PbPb
nominal LHC P 26Wrarr already expected to cause operational problems and poaaible long-term damage
41 PeV
BFPP1 Beam power 17 kW (peak)cP L E
26
Secondary beams from Pb-Pb collisions (Lattice V4 baseline)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
IP
208Pb81+ (BFPP1)208Pb80+ (BFPP2)
206Pb82+ (EMD2)
207Pb82+ (EMD1)
M Schaumann Workshop on Ions at the FCC CERN
27
Smaller Z Ions ndash Impact on hadronic event count
20140922
bull Lower Z possibly higher available from injectors
bull Contribution of ultra-peripheral electromagnetic processes to the total cross-section would be reduced
Increased luminosity lifetime more particles available for hadronic interactions
Reduced secondary beam power emerging from collision point
bull Radiation damping rate does not change much for Zgt60o
o Lower Z beams would put more burn-off into hadronic events
o Worth considering small Z reduction from Pb to eg
(6--8)hadronic
BFPP EMD
hh tot
h
N Ldt N Z
Z
( )(Pb)L ZL
28
Heavy-Ion Beam Parameter Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
29
Heavy-Ion Luminosity Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
30
Future work neededbull Number of active experiments to be considered very carefully
1 or 2 bull Counter measures for (few kW) secondary beams from IPs
ndash Robust collimatorsabsorbers in dispersion suppressorsndash Shower calculations magnet quench risks etc
bull Include heavy ion beams in future evolution of injector chainndash Maximise no of ions injected in colliderndash Do we have to live with present limits in SPS
bull Extend LHC heavy-ion collimation studies to FCCndash Does synchrotron radiation damping solve this for us
bull Vacuum effects
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Collaboration welcome
31
Conclusions and Outlookbull With very conservative assumptions (past LHC Pb
beams) FCC-hh has clear potential for high luminosity nucleus-nucleus and proton-nucleus collisions
bull New highly efficient collider regime of strong radiation damping can be fully exploited with heavy-ion beams
bull Photon-photon and photonuclear processes create powerful secondary beams emerging from IPndash Foresee counter-measures from the start (cf LHC experience)
bull Extreme luminosity burn-off is a fact of nature ndash physics community might want to consider somewhat lower-Z species
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
32
BACKUP SLIDES
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
22
POTENTIAL LIMITATIONS
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
23
Beam-Beam Tune Shift
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam-Beam Parameter per Experiment
Unit LHC Designp-p
LHC DesignPb-Pb
FCCPb-Pb
FCCp-Pb
Initial [ 37 018 037 037
Peak [ 37 018 14 83
Beam-beam tune shift per experimentbull Beam m receives kick from Beam n bull uv =x y
The tune shift due to beam-beam interactions remains well below assumed limit for Pb-Pb but comes close to the limit for Pb in p-Pb collisions
Pb-Pb
p-Pb
γ-γ and γ-A processes in Pb-Pb collisions at FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015 24
2
208208 208
208208
20882 82 82
82 82 8
08208 82 208 82 82 20
20 20
8 8
8 2
8
0
1
7 82
B
BFPP2 Pb Pb Pb Pb 2e 10 mb
FPP1 Pb Pb Pb e 354 b 001235
EMD1 Pb Pb Pb n 20
00Pb
b
2
P
500
0
208208 82 8208 02 2 6 88 2 2
b 000485EMD2 Pb Pb P b 2n
35 b 000970Pb
Each of these makes a secondary beam emerging from the IP with rigidity change
Pb1 11 m mQ Q
Extensively discussed for LHC
Hadronic cross section is 8 b (so much less power in debris)
25
BFPP1 Beam Power in Pb-Pb for FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Countermeasures (eg DS collimators) have to be considered in initial lattice amp hardware design
FCC-PbPb
nominal LHC P 26Wrarr already expected to cause operational problems and poaaible long-term damage
41 PeV
BFPP1 Beam power 17 kW (peak)cP L E
26
Secondary beams from Pb-Pb collisions (Lattice V4 baseline)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
IP
208Pb81+ (BFPP1)208Pb80+ (BFPP2)
206Pb82+ (EMD2)
207Pb82+ (EMD1)
M Schaumann Workshop on Ions at the FCC CERN
27
Smaller Z Ions ndash Impact on hadronic event count
20140922
bull Lower Z possibly higher available from injectors
bull Contribution of ultra-peripheral electromagnetic processes to the total cross-section would be reduced
Increased luminosity lifetime more particles available for hadronic interactions
Reduced secondary beam power emerging from collision point
bull Radiation damping rate does not change much for Zgt60o
o Lower Z beams would put more burn-off into hadronic events
o Worth considering small Z reduction from Pb to eg
(6--8)hadronic
BFPP EMD
hh tot
h
N Ldt N Z
Z
( )(Pb)L ZL
28
Heavy-Ion Beam Parameter Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
29
Heavy-Ion Luminosity Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
30
Future work neededbull Number of active experiments to be considered very carefully
1 or 2 bull Counter measures for (few kW) secondary beams from IPs
ndash Robust collimatorsabsorbers in dispersion suppressorsndash Shower calculations magnet quench risks etc
bull Include heavy ion beams in future evolution of injector chainndash Maximise no of ions injected in colliderndash Do we have to live with present limits in SPS
bull Extend LHC heavy-ion collimation studies to FCCndash Does synchrotron radiation damping solve this for us
bull Vacuum effects
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Collaboration welcome
31
Conclusions and Outlookbull With very conservative assumptions (past LHC Pb
beams) FCC-hh has clear potential for high luminosity nucleus-nucleus and proton-nucleus collisions
bull New highly efficient collider regime of strong radiation damping can be fully exploited with heavy-ion beams
bull Photon-photon and photonuclear processes create powerful secondary beams emerging from IPndash Foresee counter-measures from the start (cf LHC experience)
bull Extreme luminosity burn-off is a fact of nature ndash physics community might want to consider somewhat lower-Z species
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
32
BACKUP SLIDES
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
23
Beam-Beam Tune Shift
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Beam-Beam Parameter per Experiment
Unit LHC Designp-p
LHC DesignPb-Pb
FCCPb-Pb
FCCp-Pb
Initial [ 37 018 037 037
Peak [ 37 018 14 83
Beam-beam tune shift per experimentbull Beam m receives kick from Beam n bull uv =x y
The tune shift due to beam-beam interactions remains well below assumed limit for Pb-Pb but comes close to the limit for Pb in p-Pb collisions
Pb-Pb
p-Pb
γ-γ and γ-A processes in Pb-Pb collisions at FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015 24
2
208208 208
208208
20882 82 82
82 82 8
08208 82 208 82 82 20
20 20
8 8
8 2
8
0
1
7 82
B
BFPP2 Pb Pb Pb Pb 2e 10 mb
FPP1 Pb Pb Pb e 354 b 001235
EMD1 Pb Pb Pb n 20
00Pb
b
2
P
500
0
208208 82 8208 02 2 6 88 2 2
b 000485EMD2 Pb Pb P b 2n
35 b 000970Pb
Each of these makes a secondary beam emerging from the IP with rigidity change
Pb1 11 m mQ Q
Extensively discussed for LHC
Hadronic cross section is 8 b (so much less power in debris)
25
BFPP1 Beam Power in Pb-Pb for FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Countermeasures (eg DS collimators) have to be considered in initial lattice amp hardware design
FCC-PbPb
nominal LHC P 26Wrarr already expected to cause operational problems and poaaible long-term damage
41 PeV
BFPP1 Beam power 17 kW (peak)cP L E
26
Secondary beams from Pb-Pb collisions (Lattice V4 baseline)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
IP
208Pb81+ (BFPP1)208Pb80+ (BFPP2)
206Pb82+ (EMD2)
207Pb82+ (EMD1)
M Schaumann Workshop on Ions at the FCC CERN
27
Smaller Z Ions ndash Impact on hadronic event count
20140922
bull Lower Z possibly higher available from injectors
bull Contribution of ultra-peripheral electromagnetic processes to the total cross-section would be reduced
Increased luminosity lifetime more particles available for hadronic interactions
Reduced secondary beam power emerging from collision point
bull Radiation damping rate does not change much for Zgt60o
o Lower Z beams would put more burn-off into hadronic events
o Worth considering small Z reduction from Pb to eg
(6--8)hadronic
BFPP EMD
hh tot
h
N Ldt N Z
Z
( )(Pb)L ZL
28
Heavy-Ion Beam Parameter Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
29
Heavy-Ion Luminosity Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
30
Future work neededbull Number of active experiments to be considered very carefully
1 or 2 bull Counter measures for (few kW) secondary beams from IPs
ndash Robust collimatorsabsorbers in dispersion suppressorsndash Shower calculations magnet quench risks etc
bull Include heavy ion beams in future evolution of injector chainndash Maximise no of ions injected in colliderndash Do we have to live with present limits in SPS
bull Extend LHC heavy-ion collimation studies to FCCndash Does synchrotron radiation damping solve this for us
bull Vacuum effects
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Collaboration welcome
31
Conclusions and Outlookbull With very conservative assumptions (past LHC Pb
beams) FCC-hh has clear potential for high luminosity nucleus-nucleus and proton-nucleus collisions
bull New highly efficient collider regime of strong radiation damping can be fully exploited with heavy-ion beams
bull Photon-photon and photonuclear processes create powerful secondary beams emerging from IPndash Foresee counter-measures from the start (cf LHC experience)
bull Extreme luminosity burn-off is a fact of nature ndash physics community might want to consider somewhat lower-Z species
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
32
BACKUP SLIDES
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
γ-γ and γ-A processes in Pb-Pb collisions at FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015 24
2
208208 208
208208
20882 82 82
82 82 8
08208 82 208 82 82 20
20 20
8 8
8 2
8
0
1
7 82
B
BFPP2 Pb Pb Pb Pb 2e 10 mb
FPP1 Pb Pb Pb e 354 b 001235
EMD1 Pb Pb Pb n 20
00Pb
b
2
P
500
0
208208 82 8208 02 2 6 88 2 2
b 000485EMD2 Pb Pb P b 2n
35 b 000970Pb
Each of these makes a secondary beam emerging from the IP with rigidity change
Pb1 11 m mQ Q
Extensively discussed for LHC
Hadronic cross section is 8 b (so much less power in debris)
25
BFPP1 Beam Power in Pb-Pb for FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Countermeasures (eg DS collimators) have to be considered in initial lattice amp hardware design
FCC-PbPb
nominal LHC P 26Wrarr already expected to cause operational problems and poaaible long-term damage
41 PeV
BFPP1 Beam power 17 kW (peak)cP L E
26
Secondary beams from Pb-Pb collisions (Lattice V4 baseline)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
IP
208Pb81+ (BFPP1)208Pb80+ (BFPP2)
206Pb82+ (EMD2)
207Pb82+ (EMD1)
M Schaumann Workshop on Ions at the FCC CERN
27
Smaller Z Ions ndash Impact on hadronic event count
20140922
bull Lower Z possibly higher available from injectors
bull Contribution of ultra-peripheral electromagnetic processes to the total cross-section would be reduced
Increased luminosity lifetime more particles available for hadronic interactions
Reduced secondary beam power emerging from collision point
bull Radiation damping rate does not change much for Zgt60o
o Lower Z beams would put more burn-off into hadronic events
o Worth considering small Z reduction from Pb to eg
(6--8)hadronic
BFPP EMD
hh tot
h
N Ldt N Z
Z
( )(Pb)L ZL
28
Heavy-Ion Beam Parameter Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
29
Heavy-Ion Luminosity Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
30
Future work neededbull Number of active experiments to be considered very carefully
1 or 2 bull Counter measures for (few kW) secondary beams from IPs
ndash Robust collimatorsabsorbers in dispersion suppressorsndash Shower calculations magnet quench risks etc
bull Include heavy ion beams in future evolution of injector chainndash Maximise no of ions injected in colliderndash Do we have to live with present limits in SPS
bull Extend LHC heavy-ion collimation studies to FCCndash Does synchrotron radiation damping solve this for us
bull Vacuum effects
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Collaboration welcome
31
Conclusions and Outlookbull With very conservative assumptions (past LHC Pb
beams) FCC-hh has clear potential for high luminosity nucleus-nucleus and proton-nucleus collisions
bull New highly efficient collider regime of strong radiation damping can be fully exploited with heavy-ion beams
bull Photon-photon and photonuclear processes create powerful secondary beams emerging from IPndash Foresee counter-measures from the start (cf LHC experience)
bull Extreme luminosity burn-off is a fact of nature ndash physics community might want to consider somewhat lower-Z species
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
32
BACKUP SLIDES
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
25
BFPP1 Beam Power in Pb-Pb for FCC-hh
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Countermeasures (eg DS collimators) have to be considered in initial lattice amp hardware design
FCC-PbPb
nominal LHC P 26Wrarr already expected to cause operational problems and poaaible long-term damage
41 PeV
BFPP1 Beam power 17 kW (peak)cP L E
26
Secondary beams from Pb-Pb collisions (Lattice V4 baseline)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
IP
208Pb81+ (BFPP1)208Pb80+ (BFPP2)
206Pb82+ (EMD2)
207Pb82+ (EMD1)
M Schaumann Workshop on Ions at the FCC CERN
27
Smaller Z Ions ndash Impact on hadronic event count
20140922
bull Lower Z possibly higher available from injectors
bull Contribution of ultra-peripheral electromagnetic processes to the total cross-section would be reduced
Increased luminosity lifetime more particles available for hadronic interactions
Reduced secondary beam power emerging from collision point
bull Radiation damping rate does not change much for Zgt60o
o Lower Z beams would put more burn-off into hadronic events
o Worth considering small Z reduction from Pb to eg
(6--8)hadronic
BFPP EMD
hh tot
h
N Ldt N Z
Z
( )(Pb)L ZL
28
Heavy-Ion Beam Parameter Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
29
Heavy-Ion Luminosity Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
30
Future work neededbull Number of active experiments to be considered very carefully
1 or 2 bull Counter measures for (few kW) secondary beams from IPs
ndash Robust collimatorsabsorbers in dispersion suppressorsndash Shower calculations magnet quench risks etc
bull Include heavy ion beams in future evolution of injector chainndash Maximise no of ions injected in colliderndash Do we have to live with present limits in SPS
bull Extend LHC heavy-ion collimation studies to FCCndash Does synchrotron radiation damping solve this for us
bull Vacuum effects
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Collaboration welcome
31
Conclusions and Outlookbull With very conservative assumptions (past LHC Pb
beams) FCC-hh has clear potential for high luminosity nucleus-nucleus and proton-nucleus collisions
bull New highly efficient collider regime of strong radiation damping can be fully exploited with heavy-ion beams
bull Photon-photon and photonuclear processes create powerful secondary beams emerging from IPndash Foresee counter-measures from the start (cf LHC experience)
bull Extreme luminosity burn-off is a fact of nature ndash physics community might want to consider somewhat lower-Z species
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
32
BACKUP SLIDES
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
26
Secondary beams from Pb-Pb collisions (Lattice V4 baseline)
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
IP
208Pb81+ (BFPP1)208Pb80+ (BFPP2)
206Pb82+ (EMD2)
207Pb82+ (EMD1)
M Schaumann Workshop on Ions at the FCC CERN
27
Smaller Z Ions ndash Impact on hadronic event count
20140922
bull Lower Z possibly higher available from injectors
bull Contribution of ultra-peripheral electromagnetic processes to the total cross-section would be reduced
Increased luminosity lifetime more particles available for hadronic interactions
Reduced secondary beam power emerging from collision point
bull Radiation damping rate does not change much for Zgt60o
o Lower Z beams would put more burn-off into hadronic events
o Worth considering small Z reduction from Pb to eg
(6--8)hadronic
BFPP EMD
hh tot
h
N Ldt N Z
Z
( )(Pb)L ZL
28
Heavy-Ion Beam Parameter Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
29
Heavy-Ion Luminosity Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
30
Future work neededbull Number of active experiments to be considered very carefully
1 or 2 bull Counter measures for (few kW) secondary beams from IPs
ndash Robust collimatorsabsorbers in dispersion suppressorsndash Shower calculations magnet quench risks etc
bull Include heavy ion beams in future evolution of injector chainndash Maximise no of ions injected in colliderndash Do we have to live with present limits in SPS
bull Extend LHC heavy-ion collimation studies to FCCndash Does synchrotron radiation damping solve this for us
bull Vacuum effects
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Collaboration welcome
31
Conclusions and Outlookbull With very conservative assumptions (past LHC Pb
beams) FCC-hh has clear potential for high luminosity nucleus-nucleus and proton-nucleus collisions
bull New highly efficient collider regime of strong radiation damping can be fully exploited with heavy-ion beams
bull Photon-photon and photonuclear processes create powerful secondary beams emerging from IPndash Foresee counter-measures from the start (cf LHC experience)
bull Extreme luminosity burn-off is a fact of nature ndash physics community might want to consider somewhat lower-Z species
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
32
BACKUP SLIDES
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
M Schaumann Workshop on Ions at the FCC CERN
27
Smaller Z Ions ndash Impact on hadronic event count
20140922
bull Lower Z possibly higher available from injectors
bull Contribution of ultra-peripheral electromagnetic processes to the total cross-section would be reduced
Increased luminosity lifetime more particles available for hadronic interactions
Reduced secondary beam power emerging from collision point
bull Radiation damping rate does not change much for Zgt60o
o Lower Z beams would put more burn-off into hadronic events
o Worth considering small Z reduction from Pb to eg
(6--8)hadronic
BFPP EMD
hh tot
h
N Ldt N Z
Z
( )(Pb)L ZL
28
Heavy-Ion Beam Parameter Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
29
Heavy-Ion Luminosity Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
30
Future work neededbull Number of active experiments to be considered very carefully
1 or 2 bull Counter measures for (few kW) secondary beams from IPs
ndash Robust collimatorsabsorbers in dispersion suppressorsndash Shower calculations magnet quench risks etc
bull Include heavy ion beams in future evolution of injector chainndash Maximise no of ions injected in colliderndash Do we have to live with present limits in SPS
bull Extend LHC heavy-ion collimation studies to FCCndash Does synchrotron radiation damping solve this for us
bull Vacuum effects
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Collaboration welcome
31
Conclusions and Outlookbull With very conservative assumptions (past LHC Pb
beams) FCC-hh has clear potential for high luminosity nucleus-nucleus and proton-nucleus collisions
bull New highly efficient collider regime of strong radiation damping can be fully exploited with heavy-ion beams
bull Photon-photon and photonuclear processes create powerful secondary beams emerging from IPndash Foresee counter-measures from the start (cf LHC experience)
bull Extreme luminosity burn-off is a fact of nature ndash physics community might want to consider somewhat lower-Z species
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
32
BACKUP SLIDES
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
28
Heavy-Ion Beam Parameter Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
29
Heavy-Ion Luminosity Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
30
Future work neededbull Number of active experiments to be considered very carefully
1 or 2 bull Counter measures for (few kW) secondary beams from IPs
ndash Robust collimatorsabsorbers in dispersion suppressorsndash Shower calculations magnet quench risks etc
bull Include heavy ion beams in future evolution of injector chainndash Maximise no of ions injected in colliderndash Do we have to live with present limits in SPS
bull Extend LHC heavy-ion collimation studies to FCCndash Does synchrotron radiation damping solve this for us
bull Vacuum effects
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Collaboration welcome
31
Conclusions and Outlookbull With very conservative assumptions (past LHC Pb
beams) FCC-hh has clear potential for high luminosity nucleus-nucleus and proton-nucleus collisions
bull New highly efficient collider regime of strong radiation damping can be fully exploited with heavy-ion beams
bull Photon-photon and photonuclear processes create powerful secondary beams emerging from IPndash Foresee counter-measures from the start (cf LHC experience)
bull Extreme luminosity burn-off is a fact of nature ndash physics community might want to consider somewhat lower-Z species
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
32
BACKUP SLIDES
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
29
Heavy-Ion Luminosity Summary
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
30
Future work neededbull Number of active experiments to be considered very carefully
1 or 2 bull Counter measures for (few kW) secondary beams from IPs
ndash Robust collimatorsabsorbers in dispersion suppressorsndash Shower calculations magnet quench risks etc
bull Include heavy ion beams in future evolution of injector chainndash Maximise no of ions injected in colliderndash Do we have to live with present limits in SPS
bull Extend LHC heavy-ion collimation studies to FCCndash Does synchrotron radiation damping solve this for us
bull Vacuum effects
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Collaboration welcome
31
Conclusions and Outlookbull With very conservative assumptions (past LHC Pb
beams) FCC-hh has clear potential for high luminosity nucleus-nucleus and proton-nucleus collisions
bull New highly efficient collider regime of strong radiation damping can be fully exploited with heavy-ion beams
bull Photon-photon and photonuclear processes create powerful secondary beams emerging from IPndash Foresee counter-measures from the start (cf LHC experience)
bull Extreme luminosity burn-off is a fact of nature ndash physics community might want to consider somewhat lower-Z species
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
32
BACKUP SLIDES
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
30
Future work neededbull Number of active experiments to be considered very carefully
1 or 2 bull Counter measures for (few kW) secondary beams from IPs
ndash Robust collimatorsabsorbers in dispersion suppressorsndash Shower calculations magnet quench risks etc
bull Include heavy ion beams in future evolution of injector chainndash Maximise no of ions injected in colliderndash Do we have to live with present limits in SPS
bull Extend LHC heavy-ion collimation studies to FCCndash Does synchrotron radiation damping solve this for us
bull Vacuum effects
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
Collaboration welcome
31
Conclusions and Outlookbull With very conservative assumptions (past LHC Pb
beams) FCC-hh has clear potential for high luminosity nucleus-nucleus and proton-nucleus collisions
bull New highly efficient collider regime of strong radiation damping can be fully exploited with heavy-ion beams
bull Photon-photon and photonuclear processes create powerful secondary beams emerging from IPndash Foresee counter-measures from the start (cf LHC experience)
bull Extreme luminosity burn-off is a fact of nature ndash physics community might want to consider somewhat lower-Z species
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
32
BACKUP SLIDES
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
31
Conclusions and Outlookbull With very conservative assumptions (past LHC Pb
beams) FCC-hh has clear potential for high luminosity nucleus-nucleus and proton-nucleus collisions
bull New highly efficient collider regime of strong radiation damping can be fully exploited with heavy-ion beams
bull Photon-photon and photonuclear processes create powerful secondary beams emerging from IPndash Foresee counter-measures from the start (cf LHC experience)
bull Extreme luminosity burn-off is a fact of nature ndash physics community might want to consider somewhat lower-Z species
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
32
BACKUP SLIDES
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
32
BACKUP SLIDES
JM Jowett M Schaumann FCC Week 2015 Washington DC 24 March 2015
