TTF-II Status & Prospectives Nick Walker DESY 5 th ITRP Meeting – CALTECH

Overview  Brief review of TTF activity this year Commissioning status / updateCommissioning status / update  Status of Technology  Future plans

TTF-II 800 MeV SC linac RF gun 4 MeV150 MeV bunch compressor ACC1 (M2*) Laser 3 rd harmonic cavity diagnostic section beam dump 12 MV/m20 MV/m ACC2(M1*) ACC3(M3*) ACC4(M4) ACC5(M5) Successfully commissioned with beam Successfully commissioned with RF power (hp coupler conditioning)

TTF-II 800 MeV SC linac RF gun 4 MeV150 MeV bunch compressor ACC1 (M2*) Laser 3 rd harmonic cavity diagnostic section beam dump 12 MV/m20 MV/m ACC2(M1*) ACC3(M3*) ACC4(M4) ACC5(M5) Dark current & radiation measurements at 25MV/m  Pagani

TTF-II Injector Commissioning RF gun 4 MeV150 MeV bunch compressor ACC1 (M2*) ACC2(M1*) ACC3(M3*) Laser 3 rd harmonic cavity diagnostic section beam dump 12 MV/m20 MV/m  RF Gun: 21-Feb-2004 start conditioning21-Feb-2004 start conditioning 6-Mar Hz, 900 us, 3 MW6-Mar Hz, 900 us, 3 MW 16-Mar Hz, 450 us, 3 MW16-Mar Hz, 450 us, 3 MW 17-Mar-2004 first beam in gun section17-Mar-2004 first beam in gun section  Injector: 15-Apr-2004 start injector commissioning15-Apr-2004 start injector commissioning 7-Jun-2004 end commissioning7-Jun-2004 end commissioning  Linac: 20-Aug-2004restart with complete machine20-Aug-2004restart with complete machine

TTF-II Injector Commissioning RF gun 4 MeV150 MeV bunch compressor ACC1 (M2*) ACC2(M1*) ACC3(M3*) Laser 3 rd harmonic cavity diagnostic section beam dump 12 MV/m20 MV/m  RF Gun: 21-Feb-2004 start conditioning21-Feb-2004 start conditioning 6-Mar Hz, 900 us, 3 MW6-Mar Hz, 900 us, 3 MW 16-Mar Hz, 450 us, 3 MW16-Mar Hz, 450 us, 3 MW 17-Mar-2004 first beam in gun section17-Mar-2004 first beam in gun section  Injector: 15-Apr-2004 start injector commissioning15-Apr-2004 start injector commissioning 7-Jun-2004 end commissioning7-Jun-2004 end commissioning  Linac: 20-Aug-2004restart with complete machine20-Aug-2004restart with complete machine ACC1 coupler conditioning 35MV/m EP cavity test

The 35MV/m Cryomodule Test 35MV/m 510 9 AC72: one of five high- performance EP cavities

The 35MV/m Cryomodule Test AC72: one of five high- performance EP cavities 35MV/m 510 9 Acceptance test in vertical cryostat naked cavity Low power CW

The 35MV/m Cryomodule Test 35MV/m 510 9 Acceptance test in vertical cryostat HP coupler Tuner (fast/slow) full power (system) test Full 1/8 th CM horizontal test (CHECHIA) Transferred to AC72: one of five high- performance EP cavities

The 35MV/m Cryomodule Test Acceptance test in vertical cryostat Full 1/8 th CM horizontal test (CHECHIA) Transferred to Full 8 string CM TTF Transferred to AC72: one of five high- performance EP cavities

The 35MV/m Cryomodule Test Acceptance test in vertical cryostat Full 1/8 th CM horizontal test (CHECHIA) Transferred to Full 8 string CM TTF Transferred to 35 MV/m EP TESLA Cavity accelerates beam for the first time 35 MV/m EP TESLA Cavity accelerates beam for the first time RF pulse with feedback in cavity 5 (AC72) during beam acceleration AC72: one of five high- performance EP cavities

The 35MV/m Cryomodule Test RF measurements showed no degradation of performance (35MV/m achieved) RF gradient measurement calibrated using beam (energy spectrometer) No measurable radiation detected (no dark current) No time for long-term system test due to TTF-II commissioning, but… RF pulse with feedback in cavity 5 (AC72) during beam acceleration 35 MV/m EP TESLA Cavity accelerates beam for the first time 35 MV/m EP TESLA Cavity accelerates beam for the first time

AC73 Full System Test in 1/8 th Cryomodule (CHECHIA)  1100 hr continuous operation at 35MV/m  No ‘faults’ observed due to couplersdue to couplers nor due to cavitiesnor due to cavities  Forced ‘trips’ caused no damage to cavity/coupler No performance degradation observedNo performance degradation observed

AC70: New EP Result! Measured Q 0 factor 2 over TESLA-800 specification May MV/m 510 9

TTF-II Injector Commissioning RF gun 4 MeV150 MeV bunch compressor ACC1 (M2*) ACC2(M1*) ACC3(M3*) Laser 3 rd harmonic cavity diagnostic section beam dump 12 MV/m20 MV/m  RF Gun: 21-Feb-2004 start conditioning21-Feb-2004 start conditioning 6-Mar Hz, 900 us, 3 MW6-Mar Hz, 900 us, 3 MW 16-Mar Hz, 450 us, 3 MW16-Mar Hz, 450 us, 3 MW 17-Mar-2004 first beam in gun section17-Mar-2004 first beam in gun section  Injector: 15-Apr-2004 start injector commissioning15-Apr-2004 start injector commissioning 7-Jun-2004 end commissioning7-Jun-2004 end commissioning  Linac: 20-Aug-2004restart with complete machine20-Aug-2004restart with complete machine Problem-free commissioning of full ACC1 module for TTF-II operation

ACC1 Module Commissioning  Cavities limits: C1 (Z54) 18 MV/m C2 (Z51) 16 MV/m Lower limit for ACC1 C3 (D42) 20 MV/m C4 (D37) 27 MV/m power limited  C5 (AC72) 36 MV/m no FE C6 (C47) 23 MV/m C7 (Z53) 20 MV/m large FE large Lorentz forces C8 (AC69) 18 MV/m large FE time (us) gradient phase Note: high-gradients not needed for ACC1 (beam dynamics)

TTF Beam Measurements beam energy (MeV) Beam energy vs ACC1 phase Energy spread vs ACC1 phase rms energy spread (MeV) ACC1 phase (deg)

Energy stability and Energy spread  Measured in the BC dispersive section after acceleration  LLRF with closed loop  energy stable within 0.1 %, rms =  uncorrelated energy spread estimated from rising edge 25 to 30 keV Energy

Injector Commissioning: Other Highlights  Successful commissioning of bunch compressor BC2  Emittance measurements downstream of BC2 using four wire array station  Cavity as BPM… All possible due to ACC1 stable operation (turn-key system)

Measurement of Beam Position in Cavity using Dipole Mode  The signal of a dipole mode in a cavity can be used as an indication of the beam position (à la NLC) example for vertical steering and dipole mode response in C1 mode ‘centre’

example for vertical steering and dipole mode response in C1 mode ‘centre’ Resolution: <50m 4 dipole modes which couple strongly to the beam All modes co-axial within measurement resolution (50m) Measurement of Beam Position in Cavity using Dipole Mode  The signal of a dipole mode in a cavity can be used as an indication of the beam position (à la NLC)

Klystrons: 3 Active Companies  THALUS First producer of prototype achieving specs.First producer of prototype achieving specs. 2 additional ‘production’ models2 additional ‘production’ models Tests of modified tubes in July.Tests of modified tubes in July.   CPI 1 st prototype development Achieved 10MW for short pulse (tens of s, =60%) Problems with longer pulse (understood and being addressed)   TOSHIBA First prototype being prepared for initial testing (July)

Klystrons: 3 Active Companies   THALUS First producer of prototype achieving specs. 2 additional ‘production’ models Tests of modified tubes in July.  CPI 1st prototype development1st prototype development Achieved 10MW for short pulse (tens of s, h=60%)Achieved 10MW for short pulse (tens of s, h=60%) Problems with longer pulse (understood and being addressed)Problems with longer pulse (understood and being addressed)   TOSHIBA First prototype being prepared for initial testing (July)

Klystrons: 3 Active Companies   THALUS First producer of prototype achieving specs. 2 additional ‘production’ models Tests of modified tubes in July.   CPI 1st prototype development Achieved 10MW for short pulse (tens of ms, h=60%) Problems with longer pulse (understood and being addressed)  TOSHIBA First prototype being prepared for initial testing (July)First prototype being prepared for initial testing (July) In addition: pulse cable testing starts this week at DESY

Immediate TTF-II Schedule We are here Beam in modules MV/m TEST

Saturation in wavelength range nmJuly 2005 User operation (extended period) Operation with full electron beam current (to be defined; 2.25 MHz?) Dec User operation (extended period) 3rd Harmonic RF system and ACC6 installedFeb GeV beam energyApril 2006 Saturation 6 nmJune 2006 User operation (extended period) Seeding Option installedDec Seeding demonstrationApril 2007 Longer Term

Saturation in wavelength range nmJuly 2005 User operation (extended period) Operation with full electron beam current (to be defined; 2.25 MHz?) Dec User operation (extended period) 3rd Harmonic RF system and ACC6 installedFeb GeV beam energyApril 2006 Saturation 6 nmJune 2006 User operation (extended period) Seeding Option installedDec Seeding demonstrationApril 2007 Longer Term

High-Gradient Program  30 new cavities from industry on order First delivery August 2004 (total ~110)First delivery August 2004 (total ~110)  Will be put through our established procedures Electro-polishing, HPR etc.Electro-polishing, HPR etc. No modifications to any aspect foreseenNo modifications to any aspect foreseen  8 >35MV/m cavities will be installed into Cryomodule #6 Tests will either be in TTF linac orTests will either be in TTF linac or New Module Test Stand (supported in part by new EUROFEL money)New Module Test Stand (supported in part by new EUROFEL money) Date: 2006Date: 2006

High-Gradient Program   30 new cavities from industry on order First delivery August 2004  Will be put through our established procedures Electro-polishing, HPR etc.Electro-polishing, HPR etc. No modifications to any aspect foreseenNo modifications to any aspect foreseen   8 >35MV/m cavities will be installed into Cryomodule #6 Tests will either be in TTF linac or New Module Test Stand (financed by new EU XFEL money) Date: 2006

Final Comments  TTF-II (on-going) commissioning on schedule Turn-key stable operationTurn-key stable operation  TTF-II (5 accelerating modules, 800 MeV) will be fully commissioned this year All the demands of a light source user facilityAll the demands of a light source user facility  ACC6 (35MV/m) scheduled for 2006  Successful transfer of 35MV/m to a standard TTF cryomodule has been demonstrated in ACC1 Acceleration with beamAcceleration with beam No radiation measured (no dark current)No radiation measured (no dark current)  Process to produce 35MV/m cavities now established and well understood Quality control required already exceeded by standard industry practiseQuality control required already exceeded by standard industry practise  Dark current under control  Pagani  XFEL activity rapidly ramping up  Brinkmann