R. Corsini, CTF3 results in /2/2011 CLIC MEETING 1 CTF3 Experimental results in 2010 R. Corsini for the CTF3 Team R. Corsini, CTF3 results in /2/2011 CLIC MEETING 2 CTF3 Experimental results in 2010 Talk Outline Improvements in CTF3 commissioning/operation - Stability Commissioning - Drive Beam Generation status High Power RF tests PETS power production High Power RF tests Two Beam Acceleration Improvements in CTF3 commissioning/operation - Stability Commissioning - Drive Beam Generation status High Power RF tests PETS power production High Power RF tests Two Beam Acceleration R. Corsini, CTF3 results in /2/2011 CLIC MEETING 3 Covered fully or in part in CTF3 CLIC Feasibility Issues R. Corsini, CTF3 results in /2/2011 CLIC MEETING 4 R. Corsini, CTF3 results in /2/2011 CLIC MEETING 5 Drive Beam Generation Bunch train recombination 2 x 4 in DL and CR (from 3.5 to 28 A) Transverse rms emittance < 150 mm mrad (combined beam) Bunch length control to < 1 mm rms (combined beam) Beam current stability ~ 0.1 % for combined beam RF Power Production 20.8 A beam-powered test of a single PETS (without re-circulation) in the TBTS 135 MW (with 28 A potentially available in CLEX, the peak power can reach 240 MW) 140 ns total pulse length A measured breakdown rate in the range of or lower Operation of a few hundred hours at 1 Hz 7.4(10) A beam-powered test of a single PETS with external recirculation in TBTS 135 (81) MW circulating power or 65 (65) MW available for accelerating testing 250 ns total pulse length, 100 (170) ns flattish-top A measured breakdown rate in the range of or lower Operation of a few hundred hours at 5 Hz On/off/adjust will be demonstrated using the external reflection/recirculation system mounted on one of the PETS in TBL. Two Beam Acceleration issues TBTS Improved measurements of power and energy loss. Breakdown transverse kick measurements. Probe Beam energy gain and beam loading tests. TBL The current schedule is to have 8 PETS installed as well as a spectrometer dump for energy spectrum studies, toward the summer This will allow to verify transport of a beam with up to 30% of the energy extracted. CTF main goals (feasibility demonstration benchmarks) 5 th ACE February 2010 slide R. Corsini, CTF3 results in /2/2011 CLIC MEETING 6 Late start-up after fire in klystron gallery, in spite of fast and efficient recovery Total delay about 6 months Re-start with beam 24 th June First beam in CR 14 th July First CALIFES beam end July First D. Beam in TBTS early August Reduced current, from 4.5 A to 3.5 A in linac, in order to recover energy loss from missing klystron CTF3 pulse- forming network after fire ~ 24 A R. Corsini, CTF3 results in /2/2011 CLIC MEETING 7 Operational improvements Careful setting up of RF pulses (minimize amplitude/phase variation) Shaped RF pulse to minimize E/E Many optic checks, dispersion measurements, quad scans, response matrix studies, optics model much better understood and adapted CTF3 now runs on design optics acceptance improved CCC supervision of klystrons at night/WE Extensive use of reference signals faster setting up of the machine, reproducibility DLTL1CR Simona Bettoni, Piotr Skowronski, Javier Barranco et al. Dispersion Tobias Persson R. Corsini, CTF3 results in /2/2011 CLIC MEETING 8 Hardware upgrades, Feed-back systems Alexey Dubrovskiy Compensated phase variation = 10 deg over 10 hours Residual phase variation = 2 deg, ~ 0.4 deg F-B TUNED FEED-BACK ON RF temperature feedback for pulse compression RF phase feedback now fully operational Alexey Dubrovskiy Improvements in low-level and high-power RF Gun improvements (new heater power supply, ) R. Corsini, CTF3 results in /2/2011 CLIC MEETING 9 Feed-backs plus optics improvements performance, reproducibility, stability R. Corsini, CTF3 results in /2/2011 CLIC MEETING 10 Beam current in Linac zoom Mean over 1 s Piotr Skowronski Tobias Persson About 4% RF interlocks ? (time inhibit) Klystron trip ? R. Corsini, CTF3 results in /2/2011 CLIC MEETING 11 Short Term Current Stability It is calculated over 20 minutes were no major drift was observed Factor 4 recombination is more stable, mainly because of larger acceptance lower losses, but also: Sub-harmonic bunchers are not used Delay Loop (and its RF deflector) is not used This data represent CTF3 stability as it was towards the end of the last run The stability monitoring system was put in place only in autumn With more careful setup better results are achieved Piotr Skowronski Tobias Persson R. Corsini, CTF3 results in /2/2011 CLIC MEETING 12 Achieved current stability Guido Sterbini, Simona Bettoni, et al. New heater power supply, better set-point, improved measurement procedures I/I ~ 0.75 Gun feed-back I/I~ (or lower) Below CLIC DB specs! R. Corsini, CTF3 results in /2/2011 CLIC MEETING 13 The measured beam current stability in the linac is indeed 2.510 -4 ! A single BPM measurement is on average around 510 -4 We are reaching limits of our BPMs precision large influence of BPM noise The quoted value is obtained taking the sum of all linac BPMs (eliminates uncorrelated jitter) R. Corsini, CTF3 results in /2/2011 CLIC MEETING 14 Current stability 2009 measurements for factor 8 CL.SVBPM0502SCT.SVBPM0515SCR.SVBPM0155S Min. (A) Max. (A) Mean (A) Std (A) Variation (%) R. Corsini, CTF3 results in /2/2011 CLIC MEETING 15 Measurements of klystron phase and power indicate pulse-to-pulse average phase stability with respect to local reference phase for each 10 ns times slice the pulse to pulse jitter is 0.07 pulse-to-pulse power stability of < 0.2% gradient stability 0.1% Corresponds to CLIC drive beam accelerator specs Achieved klystron RF phase stability Alexey Dubrovskiy R. Corsini, CTF3 results in /2/2011 CLIC MEETING 16 Beam current along TL2, TL2 and` TBTS previously difficult to transport the beam through TL2 (BPM system problems) new BPM system works fine (except overloaded front-end crates) optics model better understood (from kick measurements) improved transport to TBTS and through PETS > 17 A delivered to TBTS Small losses for non-combined beam Small losses in TL2 for combined beam Still to be improved: ring extraction, TL2 Transfer Lines Tl2, TL2 Simona Bettoni x8 recombination R. Corsini, CTF3 results in /2/2011 CLIC MEETING 17 Drive Beam Generation Goals Bunch train recombination 2 x 4 in DL and CR (from 3.5 to 28 A) Transverse rms emittance < 150 mm mrad (combined beam) Bunch length control to < 1 mm rms (combined beam) Beam current stability ~ 0.1 % for combined beam Achievements Bunch train recombination 2 x 4 in DL and CR (from 3 to 24 A) Transverse rms emittance < 150 mm mrad (combined beam) for vertical plane Horizontal plane still a large factor off for combined beam(~ 500 mm mrad in CLEX) Bunch length control to ~ 2 mm rms (combined beam) - large R56 in end-of-linac chicane Beam current stability < 0.06 % at the end of linac or ~ 0.1 % for combination factor 2 (DL) and 4 (CR) still one order of magnitude off for combination factor 8 R. Corsini, CTF3 results in /2/2011 CLIC MEETING 18 Drive Beam Optimization for RF power production 20 deg 100 deg 12 GHz RF phase Erik Adli, Reidar Lillestl => Anne Dabrowski Bunch length Combination phase Phase variation along the pulse All affecting power production efficiency (form factor F) (final) bunch length -between 2 and 2.5 mm rms RF phase example linac energy profile R. Corsini, CTF3 results in /2/2011 CLIC MEETING 19 All quadrupole movers installed and tested Time resolved spectrometer installed and tested BPMs with new read out electronics, diagnostic section with emittance meter First commissioning and measurements performed Beam matching and transport performed, BPM resolution measured PETS qualified up to 50 MW TBL status Reidar Lunde Lillestl, Steffen Doebert Successful commissioning of the TBL beam line 50 MW of 12 GHz power generated with a 17 A drive beam in agreement with theoretical predictions Turned out to be a nice diagnostics to optimize the drive beam R. Corsini, CTF3 results in /2/2011 CLIC MEETING 20 TBL status Panel to measure beam parameters and perform the matching Time resolved energy spread with 50 MW in one PETS R. Corsini, CTF3 results in /2/2011 CLIC MEETING 21 Current stability ~ 1.3%; P ~ I 2 TBL status current & power stability R. Corsini, CTF3 results in /2/2011 CLIC MEETING 22 TBL PETS power production position correlation Correlation of beam position and output power R. Corsini, CTF3 results in /2/2011 CLIC MEETING 23 Two-Beam Test Stand (TBTS) PETS before installation in the tank Re-circulation scheme TD24 accelerating structure in tank R. Corsini, CTF3 results in /2/2011 CLIC MEETING 24 RF Power Production - TBTS PETS rapidly (~ 3x10 5 pulses) reached record >200 MW peak RF power level, providing reliably pulses ~ 1o0 MW peak to accelerating structure. About twice the power needed to demonstrate 100 MV/m acceleration in a two beam experiment with TD24_vg1.8_disk structure. Roger Ruber R. Corsini, CTF3 results in /2/2011 CLIC MEETING 25 Power production [MW]Drive beam deceleration [MV] Correlate deceleration and power measurements, applying a simple two-parameter model of PETS with recirculation (g, ). Shows good reconstruction, and help identify calibration issues (here: 1 dB out of 100 dB attenuation) Erik Adli Model ident. with phase scans. TBTS RF Power Production R. Corsini, CTF3 results in /2/2011 CLIC MEETING 26 PETS Conditioning history (not complete) 150 hours at 0.8 Hz Power from PETS Power to structure Beam current Low breakdown rate operation RF Power Production - TBTS R. Corsini, CTF3 results in /2/2011 CLIC MEETING 27 Two-Beam Acceleration demonstration in CTF3 Two-Beam Test Stand Maximum probe beam acceleration of 23 MeV measured Corresponding to a gradient of 106 MV/m TD24 expected fit measurements PRELIMINARY Drive beam OFF Drive beam ON R. Corsini, CTF3 results in /2/2011 CLIC MEETING 28 Two-Beam Acceleration Test Power measured at structure output, renormalized using known attenuation Power measured at structure input PRELIMINARY Javier Barranco R. Corsini, CTF3 results in /2/2011 CLIC MEETING 29 New calibration + effective power increase Two-Beam AccelerationTwo-Beam Acceleration Test - History PRELIMINARY Javier Barranco R. Corsini, CTF3 results in /2/2011 CLIC MEETING 30 Two-Beam Acceleration Test Detuning? After having investigated all other potential explanations, the missing energy gain was tracked down to a strong (+10 MHz) detuning of the accelerating structure with respect to the nominal frequency ( 0 = GHz). The smoking gun was a measurement of the beam-induced signal from the probe beam, down-mixed to a frequency tunable reference R = MHz R = MHz R = 0 R. Corsini, CTF3 results in /2/2011 CLIC MEETING 31 Hot water tubes Detuning at 30 Detuning at 50 , 55 , 60 Oleksiy Kononenko Wilfrid Farabolini The +10 MHz detuning was then confirmed by a post-mortem bead pull measurement In order to recover the performance, a quick- and-dirty experiment with an hot water circuit was set up in the last week of the CTF3 run Two-Beam Acceleration Test detuning & temperature scan experiment Nominal Nominal + 10 MHz R. Corsini, CTF3 results in /2/2011 CLIC MEETING 32 New calibration + effective power increase Temperature control + cross-calibration problem Two-Beam AccelerationTwo-Beam Acceleration Test - History PRELIMINARY Javier Barranco R. Corsini, CTF3 results in /2/2011 CLIC MEETING 33 Oleksiy Kononenko Two-Beam test in TBTS Full simulations Power and phase measured at structure input (three consecutive pulses) Unloaded Voltage Calculations Vmax = 24.1 MV Power measured at structure input Reconstructed from output R. Corsini, CTF3 results in /2/2011 CLIC MEETING 34 Two-Beam test in TBTS Full simulations Oleksiy Kononenko R. Corsini, CTF3 results in /2/2011 CLIC MEETING 35 TD24: Tapered, wave-guide damped 24 cell structure with v g /c = MW yields ~ 100 MV/m. 10 MHz structure detuning after Two-Beam Tests confirmed in shutdown measurements (Jan 2011) Possible cause: deformation/squashing when clamping the cooling circuit onto the structure. Jiaru Shi Two-Beam test in TBTS TD24 Detuning R. Corsini, CTF3 results in /2/2011 CLIC MEETING 36 CONCLUSIONS, MY OWN CTF3 Drive Beam Generation: Fire, late start-up. But fast recovery and lots of operational improvements Most benchmarks met already Demonstrated beam current stability (in linac) better than CLIC specs as well as klystron phase stability Some work still to be done on D.B generation Next steps: TBL deceleration with 4 PETS, results by mid-2011 PETS: Fast RF conditioning of CTF3 PETS to power levels (200 MW) well above CLIC nominal Next steps: breakdown measurements in CTF3, PETS on-off (by end 2011) Accelerating structures: First two-beam acceleration test inCTF3, 100 MV/m measured Next steps: breakdown measurements and TBA with in-tune structure in CTF3 R. Corsini, CTF3 results in /2/2011 CLIC MEETING 37 AND FROM ACE REPORT TO THE CLIC/CTF3 COLLABORATION BOARD Major successes in 2010: Improved damping ring design Improved reliability of CTF3 operation and many demonstrations Initial two-beam acceleration at TBTS with PETS and TD24 Processing of PETS and T24 structures in klystron test stands. Progress on Feasibility: Excellent progress despite fire at CTF3 Drive Beam Feasibility Issues: Principles have been demonstrated in CTF3 despite lower current and lower energy Excellent results from CTF3 in the last year: Heroic efforts by CTF3 team over the last number of years CTF3 is the unique test bench for feasibility demonstrations of drive beam generation and two-beam acceleration An important test bench for benchmarking performance of PETS & CAS R. Corsini, CTF3 results in /2/2011 CLIC MEETING 38 RESERVE SLIDES R. Corsini, CTF3 results in /2/2011 CLIC MEETING 39 Bunch length control < 1 mm rms (end of linac) Full beam loading (95% transfer) high current acceleration (up to 5 A) Ring isochronicity p < Sub-Harmonic bunching with fast (< 6ns) 180 phase switch (8.5% satellites) Control of ring length to better than 0.5 mm Factor 2 combination in Delay Loop (from 3.5 to 7 A) Bunch train recombination factor 4 in Combiner Ring (from 3 to 12 A) Beam current stability ~ 0.1 % end-of-linac, ~ 0.2 % combiner ring Transverse rms emittance 100 mm mrad (end of linac) Bunch train recombination 2 x 4 in DL and CR (from 3.5 to 28 A) Transverse rms emittance < 150 mm mrad (combined beam) Bunch length control < 1 mm rms (combined beam) Beam current stability ~ 0.1 % for combined beam CTF3 Achievements What is still missing for feasibility Drive Beam Generation ~ 0.06 % end-of-linac ! R. Corsini, CTF3 results in /2/2011 CLIC MEETING 40 Beam-powered test of a PETS with external recirculation to 170 MW,