LARP Summary

LARP SummaryEric Prebys, FermilabDirector, LARP

Novemer 16, 2012

http://www.uslarp.org/


2

BNL Cavity Status and Plan for 2012-2013

Novemer 16, 2012

The design of the cavity is complete. Fabrication of the cavity with stiffening frame is in progress. We expect the fabrication to be complete at the end of

calendar year 2012. Chemistry and HPR will be done right after the fabrication of

the cavity. Vertical testing, first without HOM couplers then with HOM

couplers will be carried out through early 2013. The testing will be focused on

o Deflection voltageo HOMso Peak fieldso Possible multipacting

Prebys, LARP Summary - Joint HiLumi/LARP Meeting


ODU Cavity: Status and Plan

Development of compact deflecting/crabbing cavities was in response to the strict dimensional requirements in some current applications

Compact rf-dipole design has Low and balanced surface fields High shunt impedance Has no lower-order-mode with a

well-separated fundamental mode Work in progress

499 MHz deflecting cavity Fabrication will be completed by Nov-Dec

400 MHz crabbing cavity Preparation for processing Bulk BCP – Fixtures and parts are being

fabricated for both cavities (Nov-Dec) 750 MHz crabbing cavity

Cavity processed with bulk BCP of 150 μm Tests under way Novemer 16, 2012Prebys, LARP Summary - Joint HiLumi/LARP Meeting 3


Key Crab Cavity Points CERN is solidly behind crab cavity development

and is supporting the SPS test and working to resolve open issues. Lots of details on SPS test, which I don’t have time to show

LARP’s role in crab cavities is one of the big issues for long term project planning.

Next big step: cryomodule integration workshop at Fermilab in December

Novemer 16, 2012Prebys, LARP Summary - Joint HiLumi/LARP Meeting 4


SPS Test



• Complete rotating collimator of April 2011 worked fairly well but fragility of 1.5mm wall copper cooling tubes not appreciated at the time

• Decision made to rebuild the jaws, using same design and to reassemble the collimator using the same jaw support system, rotation mechanism, stepper system, RF shield and vacuum tank• If a location where a collimator of this design is desired at CERN is proposed,

we would evaluate and improve each of these features• New ideas on jaw support, moly shaft, rotation, RF shield, tank, BPM, etc

• Main purpose of the rebuilt RC is to verify that it can survive the damage in a HiRadMat beam test and so validate the high power, low distortion aspects

• RC as designed is too complex and slow to manufacture at SLAC• Many surfaces require 50-75 um machining tolerances as preparation for

brazes• Current estimate for shipment to CERN is Spring 2013

Rotatable Collimator Summary

Novemer 16, 2012Prebys, LARP Summary - Joint HiLumi/LARP MeetingSlide n° 6

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Prebys, LARP Summary - Joint HiLumi/LARP Meeting 7

Task 2.5 Study Topics (beam-beam) Investigate the options for HL-LHC

Choice of basic options – b*, crossing scheme Luminosity leveling techniques - talk by T.Pieloni Imperfections, mitigation of beam-beam

Develop self-consistent simulations of the beam-beam phenomena with other dynamical effects Interplay with machine impedance - talk by S.White Crab cavity, noise, offset, etc.

Help understand the experimental data from LHC as it becomes available Also use RHIC for beam-beam experiments

Support new ideas

Novemer 16, 2012


Prebys, LARP Summary - Joint HiLumi/LARP Meeting 8Novemer 16, 2012

Circular Modes and Flat Beams for LHC

A special type of coupled beam optics can convert planar betatron modes into circular modes

For circular modes, the Space Charge tune shift is determined by the maximal emittance, being independent of the minimal one

After acceleration, the beam can be transferred into the planar state, becoming flat – gain in luminosity

With flat beams, leveling can be done with b* in the crossing plane – no need for crab cavity

A.Burov* A. Burov, “Circular modes for flat beams in LHC”, HB2012


Prebys, LARP Summary - Joint HiLumi/LARP Meeting 9Novemer 16, 2012

Luminosity Scenario with Flat Beams LHC

A.Burov, A.Valishev

LHC nominal

HL-LHC25 ns

HL-LHCFlat

# Bunches 2808 2808 2808p/bunch [1011] 1.15 (0.58A) 2.2 (1.11

A)2.2 (1.11

A)eL [eV.s] 2.5 2.5 2.5sz [cm] 7.5 7.5 7.5sdp/p [10-3] 0.1 0.1 0.1gex,y [mm] 3.75 2.5 4.0, 0.4b* [cm] (baseline) 55 15 55, 15X-angle [mrad] 285 590 (12.5

s)318 (10 s)

Lumi loss factor 0.84 0.30 0.85Peak lumi [1034] 1.0 7.4 19.7Virtual lumi [1034] 1.2 24.0 23.6Leveling Crab cavity bx=11m

down


Hollow Electron Beam Tests in the SPS/LHC?



Prebys, LARP Summary - Joint HiLumi/LARP Meeting

Beam-induced damages represent one of the most dangerous and though less explored events for LHC and state-of-the-art machines.

Novel, yet-to-characterize, composite materials are under development to meet these challenges.

New sophisticated and powerful numerical tools (Hydrocodes) are used to simulate accidental events. Limitations exist as to material constitutive models.

Need to study material under direct high intensity beam pulses HRMT-14 experiment at CERN HiRadMat

Need to understand material degradation after prolonged exposure to high particle fluences. Irradiation studied at BNL

Novemer 16, 2012

Radiation Damage Studies: Context


Novemer 16, 2012 Prebys, LARP Summary - Joint HiLumi/LARP Meeting

LHC Collimation Upgrade Material Study (BNL)

Four (4) materials will make up the irradiation array:1. Molybdenum-Graphite compound2. Molybdenum3. Glidcop4. Copper-diamond

Of interest are irradiation-induced damage and degradation of key physical and mechanical properties

Thermal conductivity Thermal expansion and dimensional changes Stress-strain behavior and ductility loss Annealing temperatures for damage reversal

Obtaining of property changes as a function of dose and/or temperature Sought are effects from doses equivalent to what will be experienced at the

upgraded LHC Objective is to utilize the deduced information in the upgraded collimator design. LARP is planning to support this work.


Comments about Long Term Visitor Program The LTV program has been one of the biggest successes for

LARP. Already showed good work of current LTVs Bhat and Burov

Historically, LARP has paid transportation and living expenses for LTVs, while their home labs continued to pay their salaries.

The new push from the DOE to identify all expenses with specific projects will make this much more difficult.

Supporting LTVs becomes prohibitively expensive if LARP has to pay salary (US accounting) in addition to living expenses $50-60k/yr $350k/yr Note: even I am not 100% paid by LARP!

In the future, we will have to be more creative in supporting LTVs LARP can only pay salaries for “mainstream” LARP activities!

Does the person have to be 100% LARP? External support (e.g. CERN Project Associateships) always helpful.

In the end, every case has to be handled on an individual basis. Novemer 16, 2012Prebys, LARP Summary - Joint HiLumi/LARP Meeting 13


QXF overview

• 150 mm aperture• 140 T/m nominal

gradient• Support structure

based on aluminum shell pre-loaded with bladders

• Status of the development– Conductor and cable R&D– Magnetic and mechanical

design and analysis



Cable R&D

• Winding test in progress at FNAL, LBNL and CERN

• Goal– determine mechanical stability of

the cable during winding– Provide feed-backs for cable

optimization



Coil design Preliminary cross-section

• Different cross-sections considered



Mirror Test of Rad-hard TQ Coil at Fermilab• Demonstration of Rad-hard epoxies in high field accelerator

magnets • Matrimid 5292 (2 part Bismaleimide resin)

• May provide a factor of ~2 improvement in acceptable dose with respect to CTD 101K

• Technical/process challenges: requires high temperature for adequate viscosity, but has short pot life at these temperatures

• On 11/15 coil reached conductor limit with faster training than in previous mirror tests



Mirror Test of Rad-hard TQ Coil at Fermilab• Demonstration of Rad-hard epoxies in high field accelerator

magnets • Matrimid 5292 (2 part Bismaleimide resin)

• May provide a factor of ~2 improvement in acceptable dose with respect to CTD 101K

• Technical/process challenges: requires high temperature for adequate viscosity, but has short pot life at these temperatures

• On 11/15 coil reached conductor limit with faster training than in previous mirror tests



Integration of LARP and GAD Programs

HiLumi/CM19, Frascati, 11/14/2012 Nb3Sn IR Quadrupole Program – G. Sabbi 1

R&D Plans – HQ Platform

• HQ01e-3: magnetic measurements and quench protection studies• HQ02: test second-generation HQ coils including

provisions for coil expansion during reaction provisions for improved electrical integrity cored cables for suppression of eddy current effects

• HQM: test of special coils Rad-hard epoxies (Matrimid and Cyanate ester) New conductor designs (RRP 169, 217 and PIT wire)

• HQM mechanical optimization in view of LHQ, QXF mirrors• HQ03 model with 4 identical coils of final design and process

Realistic field quality & performance reference for HL-LHC• Depending on program needs, HQ02-03 coils could also be used to

validate new mechanical structures (BNL, longitudinal stacking)

The TQ Coil Test performed by the core program atFermilab representsa significant stepsupporting theseR&D topics forLARP/HiLumi LHC



Reminder: LARP Down Selection First (very preliminary!) pass at costs

Progress at this meeting Meeting of LARP, CERN, and DOE representatives outline

likely scope of project (but not ready to present publicly at this time)


Compare to ~$250MCompare to $12.4M/year


Next US LARP/HiLumi Meeting Probably April 8-10, 2013 (90% C.L.)

LBL or Napa Waiting final confirmation

Thanks to everyone for a productive and enjoyable few days!!



Documents

LARP Summary