DESY superconducting SASE FEL’s Jean-Paul Carneiro DESY Hamburg

DESY superconducting SASE FEL’s

Jean-Paul CarneiroDESY Hamburg

THE TESLA COLLABORATION (12 countries, 55 institutes, status 01/2004)

CANDLE YerevanYerevan Physics Institute, Yerevan

IHEP, BeijingTsingua University, BeijingPeking University

Institute of Physics, Helsinki

CEA/DSM DAPNIA CE-SaclayLAL OrsayIPN Orsay

RWT, Hochschule, AachenBESSY, BerlinHahn-Meitner Institut, BerlinMax-Born-Institut, BerlinTechnische Universität BerlinTechnische Universität DarmstadtTechnische Universität DresdenUniversität FrankfurtGKSS-Forschungszentrum GeesthachtDESY Hamburg and ZeuthenUniversität HamburgForschungszentrum KarlsruheUniversität RostockBergische Universität-GH Wuppertal

CCLRC-Daresbury and Rutherford Appleton LaboratoryRoyal Holloway, University of London Queen Mary, University of LondonUniversity College LondonUniversity of Oxford

Laboratori Nazionali di FrascatiINFN LegnaroINFN MilanINFN Rome IISincrotrone Trieste

Institut of Nuclear Physics, CracowUniversity of Mining and Metallurgy, CracowSoltan Institut for Nuclear Studies, Otwock-SwierkHigh Pressure Research Center, WarsawInstitute of Physics, WarsawPolish Atomic Energy Agency, WarsawFaculty of Physics, University of Warsaw

CIEMAT, Madrid

PSI, Villigen

ANL, Argonne, IlFNAL, Batavia, IlMIT, Cambridge, MACornell University, NJUCLA, Los Angeles, CAJlab, Newport News, VA

MEPI, MoscowITEP, MoscowBINP, NovosibirskBINP, ProtvinoIHEP, ProtvinoINR, TroitskJINR, Dubna

Jean-Paul Carneiro, FNAL, 16-Sept-04 2 DESY superconducting SASE FEL’s

• Basic principle of the Self Amplified Spontaneous Emission (SASE)

• Description of DESY superconducting SASE FEL’s

• Tesla Test Facility, Phase 1 (TTF1)• Tesla Test Facility, Phase 2 (TTF2) • Status of the European XFEL

OUTLINE


Basic principle of SASE

High peak brilliance (exceeding storage rings by several order of magnitudes). High degree of transverse coherence close to saturation

Spontaneous emission

Saturation

Exponential Growth


Successful demonstration of FEL saturation for sub-micrometers wavelengths :

• LEUTL : 385 nm (Sept. 2000)

• TTF1 : shortest wavelengths obtained at TTF1 at DESY (1st saturation @ 98 nm in Sept. 2001) saturation obtained from 80 nm to 120 nm

FEL saturation for sub-micrometer wavelengths


Tesla Test Facility, Phase 1

BC2ACC1

RF GUN UNDULATOR

BoosterCavity ACC2

To FEL diagnostics

Dump

BC1

• First beam in 1996 with a thermoionic gun• Operated from Dec. 1998 to Nov. 2002 using the FNAL photo-injector• Total length of the accelerator : ~ 120 meters, Energy : 220-270 MeV.



Photo-injector, Capture Cavity and Cryo-Modules

Undulator



BC2ACC1

RF GUN UNDULATOR

BoosterCavity

ACC2 To FEL diagnostics

Dump

BC1


Tesla Test Facility, Phase 1 / BC2 compression

upstream BC2 downstream BC2


Tesla Test Facility, Phase 1 / Radiation Characteristics

BC2ACC1

RF GUN UNDULATOR

BoosterCavity

ACC2 To FEL diagnostics

Dump

BC1

Photons • Radiation wavelength : 80-120 nm• FWHM radiation pulse duration : 30-100 fs• Energy in the radiation pulse : 30-100 µJ• Radiation peak power level : ~1.5 GW


ASTRA ELEGANT ASTRA

Reference : http://www.desy.de/s2e-simu (TTF1 Start-to-End Simulations of SASE FEL at the TESLA Test Facility, Phase 1, DESY PREPRINT 03-197, M. Dohlus, et Al.)

http://www.desy.de/s2e-simu

Tesla Test Facility, Phase 1 / FEL saturation

Average energy in the radiation pulse Vs active undulator length (numerical simulations with the FAST code)

Courtesy of M. Yurkov


Tesla Test Facility, Phase 1 / FEL radiation

Measurement of transverse coherence of the TTF1 FEL radiation

Courtesy of R. Ischebeck


Au film (15 nm) on Si substrate irradiated by a single SASE pulse

= 98 nm, W=100 TW/cm2

Tesla Test Facility, Phase 1 / Ablation experiment

Courtesy of J. Krzywinski


Tesla Test Facility, Phase 1 / Résumé

• TTF phase 1 has been concluded successfully

Saturation observed in the wavelength of 80-120 nm

Peak brilliance as expected

~1.5 GW of peak power in flashes of 30 -100 fs

Good agreement between observations and simulation codes (ASTRA / ELEGANT / FAST)


bandw.)].0.1%.mmc.mrad[Phot./(se10 2229

BC2 BC3ACC2

RF GUN

ACC3 ACC4 ACC5 ACC6

UNDULATOR

ACC1

S.H.


To FEL diagnostics

Dump


• TTF Phase 2 is an extension of TTF Phase 1 to shorter wavelengths as low as 6 nm. • Total length of the accelerator : ~ 250 meters, Energy : 1 GeV.

Tesla Test Facility, Phase 2 / Longitudinal Phase Space

upstream 3.9 GHz cavity downstream 3.9 GHz



downstream BC2 downstream BC3




-0.2 -0.1 0 0.1 0.20

0.5

1

1.5

2

2.5

3

3.5R

MS

Em

itta

nce

[mm

-mra

d]

s [mm]

xy

Tesla Test Facility, Phase 2 / Slice emittance


BC2 BC3ACC2

RF GUN

ACC3 ACC4 ACC5 ACC6

UNDULATOR

ACC1

S.H.


To FEL diagnostics

Dump

Photons • Radiation wavelength : 6 nm• FWHM radiation pulse duration : ~ 200 fs• Radiation peak power level : ~ 2.8 GW


Reference : http://www.desy.de/s2e-simu (TTF2 Optimized Version, P. Piot et Al. )


BC2 BC3ACC2

RF GUN

ACC3 ACC4 ACC5

UNDULATOR

ACC1

To FEL diagnostics

Dump

Tesla Test Facility, Phase 2 / Present Status


• 3.9 GHz cavity and ACC6 not installed (2006).

• Injector Conditioning from Jan. 2004 to June 2004 (dump downstream ACC2). Shutdown from June 2004 to Aug. 2004. Re-commissioning since Sept (dump downstream ACC5 for dark current studies).

• Cryostat : cooled at 2 K from April to June.

• RF : Modulator 3 and 2 (Gun, ACC1) OK, Mod. 5 and 4 (ACC2/3, ACC4/5/6) OK soon.

• Vacuum : > 100 ion pumps, > 50 TSP, OK.

• Diagnostics: Cameras OK, Toroids OK, BPM installed (electronics available end 2004).

Tesla Test Facility, Phase 2 / Status

RF Gun & ACC1TTF2 RF GUN



3.9 GHz cavity section and BC2 FODO lattice & ACC2



End ACC3 & BC3 ACC4 & ACC5



End ACC5 LOLA cavity



collimator section main & bypass beamline



undulator beam dump


1 1* 2 2* 3 3* 4 50

5

10

15

20

25

TESLA500

EA

CC [M

V/m

]

module

ACC2 ACC1

ACC3

ACC4 ACC5

TTF, Phase 2 / Modules Operating Gradients


Courtesy of D. Kostin

1 - Z54 2 - Z51 3 - D42 4 - D37 5 - AC72 6 - C47 7 - Z53 8 - AC690

5

10

15

20

25

30

35

FE

Mod

ule

23.04.2004

Module 2*

EA

CC [M

V/m

]

Cavity

Cryostat tests: Vertical Horizontal Module

EP cavity


Tesla Test Facility, Phase 2 / ACC1 Operation Courtesy of D. Kostin

• Laser pulse

Short Longitudinal Pulse : Gaussian :

Transverse neither gaussian nor flat :

Time (ps)0 10 20 30 40 50

Tesla Test Facility, Phase 2 / Laser


Courtesy of S. Schreiber

mm.. mm,. yx

ps.. z

Tesla Test Facility, Phase 2 / Energy Gun Vs Forward Power


0.5 1 1.5 2 2.5 32

2.5

3

3.5

4

4.5

5

Pf-Pr [MW]

Mo

me

ntu

m [M

eV

/c]

MeasurementASTRA

Tesla Test Facility, Phase 2 / Energy Gun Vs Launch Phase


0 20 40 60 80 100 1200

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

RF Gun Phase [Deg]

Mo

me

ntu

m [M

eV

/c]

MeasurementASTRA

Tesla Test Facility, Phase 2 / Energy Vs ACC1 Phase


-15 -10 -5 0 5 10 1597.5

98

98.5

99

99.5

100

100.5

101

101.5

102

102.5

Phase ACC1 [Deg]

Mo

me

ntu

m [M

eV

/c]

MeasurementASTRA

Tesla Test Facility, Phase 2 / Energy Spread Vs ACC1 Phase


-15 -10 -5 0 5 10 150

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

Phase ACC1 [Deg]

En

erg

y S

pre

ad

[Me

V]

MeasurementASTRA

z = 19 m

Magnetic length of quads 270 mm, one common power supplyDesign phase advance 45 deg

Tesla Test Facility, Phase 2 / Emittance


TTF, Phase 2 / Emittance Measurement Method


• Beam sizes are measured at four screens with fixed quadrupole currents in a FODO lattice

• Emittance and Twiss parameters calculated from the measured beam sizes and beam size errors

• FODO cell with periodic beta function is not a requirement for the emittance measurement

4 OTR + wirescanner stations

TTF, Phase 2 / Matched Beam in FODO


4DBC2 6DBC2

8DBC2 10DBC2

3 bunches, 1 nC

Solenoids at 277 A

6.4 mm

Courtesy of

K. Honkavaara

• Three different image analysis methods used to determine the beam sizes

• Since a systematic study of beam size errors is not finished yet, a conservative 10 % beam size error is assumed

Normalized horizontal and vertical emittances vs. solenoid current.

This data is still subject to further analysis, and thus preliminary!Simulation by Y. Kim

zoom

TTF, Phase 2 / Matched Beam in FODO


Courtesy of

K. Honkavaara


Tesla Test Facility, Phase 2 / First Light Scenarios

Nominal Operation

linearized compression (less sensitive to CSR and Space Charge)“long” SASE pulse (200 fs FWHM)

First Light Scenarios

3.9 GHz cavity not available445 MeV, 30 nm

“short SASE pulse (~50 fs FWHM)

(1) E. Saldin, E. Schneidmiller, M. Yurkov, “Expected Properties of the Radiation from the VUV-FEL at DESY (Femtosecond Mode of Operation)”, Proc. FEL 2004, Trieste, Italy.

(2) J.-P. Carneiro, B. Faatz, K. Floettmann, “Velocity Bunching at TTF2”, Proc. FEL 2004, Trieste, It.

“TTF1 like operation” (1)Q=0.5 nC, laser ~4 ps RMS, BC2 & BC3

“Velocity Bunching” (2)Q=1.0 nC, laser ~4 ps RMS, No Chicanes

Tesla Test Facility, Phase 2 / Velocity Bunching


-100 -50 0 50 1000

1

2

3

4

5

6

7

Phase First Cavity ACC1 [Deg]

z [m

m]

6 nC3 nC1 nC0.5 nC

ASTRA SIMULATIONSRMS bunch length Vs Phase of First Cavity of ACC1

-2.5 -2 -1.5 -1 -0.5 0 0.5 10

0.2

0.4

0.6

0.8

1

1.2

1.4

Cu

rre

nt [

kA]

s [mm]-2.5 -2 -1.5 -1 -0.5 0 0.5 1

0

1

2

3

4

5

6

7

Tra

nsv

ers

e E

mitt

an

ce [m

m-m

rad

]

0 50 100 1500

0.5

1

1.5

s [m]

Po

we

r [G

W]

Case Q = 1 nC

ELEGANT OUTPUT ENTRANCE UNDULATOR

(Z=203 m)GENESIS OUTPUT

(B. Faatz)



Pyro detector / No velocity buncing Pyro detector / With velocity bunching



Energy Vs Phase First Cavity ACC1 Energy Spread Vs Phase First Cavity ACC1

-100 -80 -60 -40 -20 00.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

Phase first cavity ACC1 [Deg]

En

erg

y sp

rea

d [M

eV

]

MeasurementASTRA

-100 -80 -60 -40 -20 088

90

92

94

96

98

100

102

104

106

108

Phase first cavity ACC1 [Deg]

Mo

me

ntu

m [M

eV

/c]

MeasurementASTRA





0.3 0.4 0.5 0.60

1

2

3

4

5

6

7

8

9x 10

-7

k [m-1]

x2 [m

2 ]

Quad Scan (Q3UBC2 / Screen 3SBC2 / L = ~ 2.7 meters / Q = 1 nC)Normalized Emittance from Quad Scan ~ 13 mm-mrad

Tesla Test Facility, Phase 2 / Résumé


• First results from TTF phase 2 encouraging

Saturation at 30 nm foreseen for late 2004 / early 2005

Shortest wavelengths and long bunch train

Operation with 3.9 Ghz cavity and ACC6 in 2006

XFEL / Version ESFRI workshop (Oct. 2003)

BC1ACC2

RF GUN

S. H. ACC5 ACC57 UNDULATORACC1 ACC3 ACC4BC2

• Total length of the facility ~ 3.3 km (~ 2km tunnel), Energy : 20 GeV.• Version presented at the “European Strategy Forum on Research Infrastructures” (ESFRI, 30-31 Oct. 2003, DESY Hamburg)


XFEL / Entrance undulator

Current distribution

-40 -20 0 20 400

1

2

3

4

5

6

7

s [m]

Cu

rre

nt [

kA]

CSR-TRACKELEGANT


XFEL / Entrance undulator

-40 -20 0 20 400

0.5

1

1.5

2

2.5

3

s [m]

Em

itta

nce

[mm

-mra

d]

CSR-TRACK XCSR-TRACK YELEGANT XELEGANT Y

slice emittance


XFEL / FEL Radiation

BC1ACC2

RF GUN

S. H. ACC5 ACC57 UNDULATORACC1 ACC3 ACC4BC2

Photons • Radiation wavelength : 0.1 nm• FWHM radiation pulse duration : 100 fs• Radiation peak power level : 24 GW


Reference : http://www.desy.de/s2e-simu (XFEL ESFRI Version, Y. Kim / T. Limberg )


• TTF1, TTF2 and XFEL

TTF1 : Saturation at 98 nm in Sept. 2001 + good agreement with simulation codes = great success for the TESLA collaboration.

TTF2 : good results TTF1+ good results conditioning TTF2 = very promising for TTF2 operation (6 nm in 2006).

XFEL : good results TTF2 + good European cooperation = European XFEL in DESY Hamburg in ~ 2012.

CONLUSION

• Major progress concerning a Superconducting Linear Collider :

35 MV/m measured in April 2004 at TTF2 with the 5th cavity of ACC1 operating with and without beam.


EXTRA SLIDES

• PITZ • Coupling Slot Fermilab RF Gun G3 • Superstructures • Old XFEL version (workshop Aug. 2003, DESY Zeuthen)


PITZ Photo-Injector (DESY Zeuthen)

Faraday Cup

Faraday CupDipoleQuadrupole triplet

• Civil construction started in 1999 and RF gun conditioning started in Oct. 2001• First beam Jan 2002• RF gun delivered to DESY Hamburg in Nov. 2003

RF GUN (with coaxial input coupler)

• 1.5 cells, π-mode, 1.3 GHz• 40 MV/m, ~ 3 MW

Main PITZ results• Max energy : ~ 4.7 MeV • Min energy spread : ~ 33 keV/c (1 nC) • Min bunch length : 6.3±1.4 mm• Min Normalized Emittance : 1.5 mm-mrad in X

1.9 mm-mrad in Y• Operation without beam at 10 Hz, 900µs and 3 MW (~27 kW)

LASER and CATHODE• 263 nm• Cs2Te photo-cathode

Transverse emittance measurementslits screen

SOLENOIDES


PITZ Photo-Injector


PITZ Photo-Injector / RF Gun during installation


PITZ Photo-Injector / ANSYS (F. Marhauser, BESSY)

• 14 water channels (1 in the back plane going twice around, 4 around the half cell, 7 around the full cell, 1 in the front plane and 1 in the iris making three loops around it)

• Max. water flow rate per channel: with max. flow velocity and channel cross section

• Total Maximum water flow rate : withhmsldt

dVi

i/]/[.

max,

cAdt

dV max max cA

]/[0.2max sm


PITZ Photo-Injector / Water Cooling System


0 5 10 15 2048

50

52

54

56

58

60

62

64

Mean Power [kW]

Te

mp

era

ture

[C]

Set PointIncomingOutgoing

0 200 400 600 80048

50

52

54

56

58

60

62

64

RF Pulse Length [s]

Te

mp

era

ture

[C]

Set PointIncomingOutgoing

PITZ Photo-Injector / RF Gun operation at 10 Hz

Temperature Vs RF pulse length Temperature Vs mean power


DETUNING OF THE PITZ GUN WITH LONG RF PULSES

Reflected power


PITZ Photo-injector / ANSYS simulations at 27 kW

• We operated at PITZ the TTF2 RF gun at 10 Hz, 900 µs, 3.0 MW. Stable operation could be reached for few minutes before vacuum interlocks. More conditioning is still needed at this mean power.

(Temp probe 1 cm in the iris hole)


PITZ Photo-injector / ANSYS simulations at 130 kW

• At 50 Hz operation, ANSYS predicts temperatures in the waveguide iris of ~170 C and stresses of ~130 MPa which are not tolerable

The operation at 50 Hz would necessitate adding more cooling channels.


PITZ Photo-Injector / Longitudinal Momentum

Mean momentum vs RF phase

0, deg

RMS momentum spread vs RF phase

0, deg

4.72 MeV/c

33 keV/c

Courtesy of D. Lipka


PITZ Photo-Injector / Longitudinal Profile Courtesy of F. Stephan

Cherenkov radiation

use of aerogel: SiO2 ,

refractive index ≈ 1.03

Bunch length (mm) in RMS 90 %:

0, deg

Minimum bunch length: FWHM = (21.04 ± 0.45stat ± 4.14syst) ps = (6.31 ± 0.14stat ± 1.24syst) mm


PITZ Photo-Injector / Emittance Vs Bucking Courtesy of F. Stephan

1 nC, -5deg, Imain = 305 A

1,0

1,2

1,4

1,6

1,8

2,0

2,2

2,4

2,6

2,8

3,0

0 10 20 30 40 50 60

Ibuck / A

no

rma

lize

d e

mit

tan

ce

/ p m

m m

rad

yx

y

x

εε

ε

ε

1.7

1.5

WR=1.2 (Spring 8, 14 MeV)


PITZ upgrade: (2004: 16 MeV, 2005: 40 MeV)

Gun Booster

PITZ Photo-injector / Résumé

RF gun conditioned and delivered to TTF2. Conditioning of new RF gun started in Jan. 2004

Next steps : • reach ~ 1.5 mm-mrad using homogenous laser profile at 40 MV/m. • reach ~ 1.2 mm-mrad using 2 ps rise/fall time (for TTF2) • reach ~ 0.9 mm-mrad (for XFEL) using 60 MV/m (10 MW klystron)

64

Coupling slot Fermilab RF Gun G3


• Injector commissioning (including FODO lattice) from Jan. to June 2004 • Shutdown from June to August 2004 (vacuum work, etc…) • Injector re-commissioning started in Sept. 2004

SUPERSTRUCTURES

• From J. Sekutowicz et Al., PRST-AB, Vol. 7, (2004)

• Superstuctures : now : 2×7 Nb cells connected by λ/2 long tubes later : 2×9 cells

• Advantages (compared to classical 9 cell TESLA cavity) :$ reduce the number of fundamental power couplers

space saving in the TESLA tunnel (up to 1.8 km)

• Results of 2 superstructures 2×7 tested in TTF1 :

field flatness < 2%, good HOM damping

bunch-to-bunch energy variation :

encouraging results

%.. EE

(TESLA SPECIFICATION)


XFEL / Old Version (Aug. 2003)

BC1 BC2ACC2 ACC3 ACC4ACC1

S.H.

ACC7

UNDULATOR

BC3 ACC8 ACC57

RF GUN

• Version presented at the workshop “Start-to-End Simulations of X-RAY FELs” (Aug. 2003, DESY Zeuthen)• Idea : extension of TTF2 at 20 GeV with 3rd bunch compressor.


Documents

DESY superconducting SASE FEL’s Jean-Paul Carneiro DESY Hamburg