ctf3 – status and plans
DESCRIPTION
CTF3 – Status and Plans. Frank Tecker – BE-OP f or the CTF3 team* * Many thanks for all the material, esp. to R.Corsini. Highlights from 2011 CLIC Feasibility Demonstration Plans for 2012 Running in 2013. CTF 3. Combiner Ring – 84m. Delay Loop – 42m. TL1. Laser. CLEX. TL2. - PowerPoint PPT PresentationTRANSCRIPT
Frank TeckerCTF3 - IEFC Workshop 2012
CTF3 – Status and Plans
Frank Tecker – BE-OPfor the CTF3 team*
* Many thanks for all the material, esp. to R.Corsini
08/03/12
Highlights from 2011CLIC Feasibility DemonstrationPlans for 2012Running in 2013
Frank TeckerCTF3 - IEFC Workshop 2012
CTF 3
CLEX
30 GHz “PETS Line”
Linac
Delay Loop – 42mCombiner Ring – 84m
Injector
Bunch lengthchicane
30 GHz test area
TL1
TL2
RF deflector
Laser
4A – 1.2µs150 MeV
32A – 140ns150 MeV
demonstrate remaining CLIC feasibility issues, in particular:
Drive Beam generation (fully loaded acceleration, bunch frequency multiplication)
CLIC accelerating structures
CLIC power production structures (PETS)
08/03/12
Frank TeckerCTF3 - IEFC Workshop 2012
200 40 0 60 0 8 00 10 00
5 0
100
150
200
250
CLICtarget pulse
12 GHz RF power
135 MW
Power Extraction Structure (PETS)
P [M
W]
t [ns]
Many improvements on optics, hardware, feed-backs, beam stability, reproducibility…
PETS operation to power levels (~250 MW) well above CLIC goal, at nominal CLIC pulse length
Measured gradient in two-beam acceleration test 145 MV/m (CLIC nominal gradient of 100 MV/m)
Nine PETS tanks installed in the Test Beam Line (TBL), 20 A decelerated by ~ 25%, matching well with expectations
First successful test of PETS with on-off mechanism
First measurements of break-down kicks in TBTS
CTF3 Highlights - 2011
Test Beam Line (TBL) in CTF3
Two-beam acceleration in TBTS
Optics model checks in Combiner Ring
08/03/12
Frank TeckerCTF3 - IEFC Workshop 2012
2011 ImprovementsGun pulse current flatteningAll RF phase sags made the same, including TWTs and MKS02Allowed for very quick setup of the factor 4 recombination in CR CTF3 Monitor: watches all signals stability, complete references, …FeedbacksIncreased recombined beam stabilityThe recombination is now much less vulnerable to drifts and jitters14A in CLEX, 13A routinely
08/03/12
Beam currentCombiner Ring4x combination
Frank TeckerCTF3 - IEFC Workshop 2012
DL current
H
V
Problems: • TWT availability – still working with 2 (out of 3) SHB only
– plus day-to-day power fluctuations => Mainly working with 3 GHz beam for most of the year
• Difficult DL set-up after last stop – suspect misaligned quadrupole (+ radiation alarm problem)
Eventually able to get good recombination (current record), but:
• Bad pulse shape (phase switches?)
• Still limited acceptance -> stability was improved, but it is still not good enough
• DL quads measured and realigned
Future work:
• Work on phase switches, gun current compensation, back to 3 TWTs, improve trajectories
P. Skowronski
Drive Beam Generation – Factor 8
08/03/12t [ns]
I [A]
Frank TeckerCTF3 - IEFC Workshop 2012
Repeatibility and long term current stability improved
Pulse charge stability measured at end of the linac better than CLIC requirements
P [M
W]
RF power feedback, MKS 13
Time [h:m]
Feedback on
Feedback off
Feedback on
Several feed-back loops operational, for temperature, RF phase and power and gun current.
G. Sterbini
Charge stabilityFactor 4
P. Skowronski, T. Persson
T. Perssons [m]
5 10-41 10-3
CTF3 Stability - Feedbacks
08/03/12
Frank TeckerCTF3 - IEFC Workshop 2012
Beam recombination - Emittance
Best results in CLEX for factor 4: eH= 250 um eV= 140 umfor factor 8: eH= 640 um eV= 170 um
Different turns are ~ ok, no unknown effectsEmittance increase due to non perfect combination
• Improve measurements• Correct dispersion (linear, nonlinear)• Correct multi-turn orbit• Control RF deflector bump
2012
Horiz. Vert.
Measurements in TL2 - uncombined
Uncombined beam
Drive Beam Generation - Emittance
08/03/12
Nor
mal
ized
rms e
mitt
ance
(mm
mra
d)
Frank TeckerCTF3 - IEFC Workshop 2012
TBL – Test Beam Line Decelerator
Drive beam has high current and gets high energy spreadStable transport in simulations verified experimentally with 9 PETSno losses in TBL, optics understoodSo far 19 A beam decelerated by ~25%, 0.5 GW power produced!Good agreement of power production, beam current and deceleration
08/03/12
9 PETS – 19 ANovember 2011
Steffen Doebert, Reidar Lillestol
TBL line in CLEX
Frank TeckerCTF3 - IEFC Workshop 2012
PETS operated routinely above 200 MW peak RF power
providing reliably pulses ~ 100 MW peak to accelerating structure.
About twice the power needed to demonstrate 100 MV/m acceleration in a two-beam experiment with TD24 structure.
2 00 4 00 60 0 80 0 1 00 0
5 0
10 0
15 0
20 0
25 0
CLICtarget pulse
12 GHz RF power in PETS
135 MW
P [M
W]
t [ns]R. Ruber, I. Syratchev
Two-Beam Test Stand (TBTS) – power production
08/03/12
Frank TeckerCTF3 - IEFC Workshop 2012
TD24
Drive beam OFF
Drive beam ON
Achieved Two-Beam Acceleration
Maximum probe beam acceleration measured: 31 MeV Corresponding to a gradient of 145 MV/m
08/03/12
Frank TeckerCTF3 - IEFC Workshop 2012
ONOFF
PETS outputTo Structure input
(as predicted by computer simulation)
TBTS PETS layout with internal recirculation to test the ON/OFF concept
Movable RF short circuit (to tune the resonant length)
Variable reflector (to tune the recirculation coupling)
Igor Syratchev
PETS ON/OFF mechanism in TBTS
08/03/12
Frank TeckerCTF3 - IEFC Workshop 2012
Simulation vs. experiment
0N
0FF
Combination x 4 0N
0FF
0N
0FF
Beam current PETS, forward RF
RF to structurePETS, reflected RF
Signal evolution during On-Off
Igor Syratchev, Alexey Dubrovskiy
PETS output, forward
PETS On-Off mechanism - results
PETS on-off principle fully tested
Conditioned at high power (135 MW - nominal) by recirculation08/03/12
PETS
1
2
3
1
3
2
Frank TeckerCTF3 - IEFC Workshop 2012
Bunch length control < 1 mm rms (end of linac)
Full beam loading (95% transfer) high current acceleration (up to 5 A)
Ring isochronicity ap < 10-4
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 p 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 p mm mrad (combined beam)
Bunch length control < 1 mm rms (combined beam)
Beam current stability ~ 0.2 % for fully combined beam
CTF3 Achievements – What is still missing for feasibility – Drive Beam Generation
~ 0.05 % end-of-linac !
13
~ 0.1 % factor 4~ 0.1% factor 2 after DL
~ 1 %
DB generation , 2012:
Improve beam quality for factor 8 beam (emittance, bunch length, stability)
CTF3 Achievements – Drive Beam
08/03/12
Frank TeckerCTF3 - IEFC Workshop 2012
Beam-powered test of a PETS with external recirculation to 170 MW, <200 ns - ~10 A beam currentPower & drive beam energy loss measurements.
CTF3 Achievements – What is still missing for feasibility – TBL / TBTS
Beam-powered test of a PETS to nominal parameters (135 MW, 240 ns) with external recirculation (10 A) and without (20 A) – including probe beamImproved power & drive beam energy loss measurements
Break-down kick measurements
PETS On-off mechanism demonstration
Drive beam phase 2012/2013
8 (12 > 16) PETS + spectrometer installed to verify transport of a 28 A beam with up to 30% of energy extracted.
Probe beam acceleration to 100 MV/m. (up to 145 MV/m measured)
14
9 PETS20 A beam25% deceleration
TBL:
• 12 PETS start 2012
• 16 PETS in 2013 (TBL+)
TBTS, 2012:
• Continue studies with two new structures
• Wakefield monitors
CTF3 Achievements – Two-Beam issues
08/03/12
Frank TeckerCTF3 - IEFC Workshop 2012
CTF3 in green colour
Technical system tests and
simulations
RF Test StandsSLAC – KEK -CERN
System Item Feasibility Issue Unit Nominal Achieved How Feasibility CommentsFully loaded accel effic % 97 95 CTF3 Freq&Current multipl - 2*3*4 2*4 CTF3Combined beam current (12 GHz) A 4.5*24=100 3.5*8=28 CTF3 Combined pulse length (12 GHz) nsec 240 140 CTF3Intensity stability 1.E-03 0.75 < 0.6 CTF3 End of DBA. To be demonstrated for combined beam in 2011Drive beam linac RF phase stability Deg (1GHZ) 0.05 0.035 CTF3, XFEL Achieved in CTF3, XFEL designPETS RF Power MW 130 >130 TBTS/SLAC PETS Pulse length ns 170 >170 TBTS/SLACPETS Breakdown rate /m < 1·10-7 ≤ 2.4 10-7 TBTS/SLACPETS ON/OFF - @ 50Hz - CTF3/TBTS 2011 Prototype under fabrication for tests with beam Drive beam to RF efficiency % 90% - CTF3/TBL
2012TBL with 8 (16) PETS in 2011(12) for 30(50%) efficiency. Benchmark beam simulation for safe extrapolation of high efficiency at high drive beam energy(2GeV).
RF pulse shape control % < 0.1% - CTF3/TBTS 2011-2012Structure Acc field MV/m 100 100Structure Flat Top Pulse length ns 170 170 Structure Breakdown rate /m MV/m.ns < 3·10-7 5·10-5(D) 2011Rf to beam transfer efficiency % 27 15 2011
Power production in Two Beam Test Stand (TBTS) Probe beam acceleration by Two Beam Test Stand(TBTS)
Drive to main beam timing stability psec 0.05 - CTF3 2012Main to main beam timing stability psec 0.07 - XFEL? 2012Emitttance generation H/V nm 500/5 3000/12 Damping Ring design nom perf. Relax emitt achieved ATFEmittance preservation: Blow-upH/V
nm 160/15 160/15 2011-12 Simulation + alignment/stabilityMain Linac components microns 15 2011Final-Doublet microns 2 to 8 2011Quad Main Linac nm>1 Hz 1.5
Final Doublet (assuming feedbacks) nm>4 Hz 0.2drive beam power [email protected] beam power of [email protected]
Operation and Machine Protection System (MPS)
CTF3 simulations 2011 Report integrating LHC experience under preparation
Principle demonstrated in CTF2, to be adapted to long distances and integrated in Two Beam Module in 2010
Vertical stabilisation
0.13 (principle)
Stabilisation Test Bench 2011-12 Adaptation to quad prototype and detector environment in
2010. Integrated in Two Beam Module with beam till 2012.
2011
Ultra low beam
emittance & sizes
Ultra low Emittances
ATF, NSLS/SLS + simulation
Alignment 10 (princ.) Alignement & Mod.Test Bench
Two Beam Acceleration
Power producton and probe beamacceleration in Two beam module MV/m - ns 100 - 170 106 - 170 TBTS
Two Beam Acceleration
Drive beam generation
Accelerating Structures
(CAS)
CTF3 Test Stand, SLAC,
KEK
Nominal performances of 3 structures without damping. 1 structure equipped with damping features under RF conditionning to reduce breakdown rate.
Novel scheme fully demonstrated in CTF3 in spite of lower current since beam dynamics more sensitive than nominal
due to lower energy (250MeV/2Gev)
Beam Driven RF
power generation
BD rate at nominal power and pulse lenght, measured on Klystron driven PETS. Beam driven tests under way in CTF3
CLIC Feasibility Benchmarks
08/03/12
Frank TeckerCTF3 - IEFC Workshop 2012
Main goals for 2012Improve beam quality: emittance, beam current (losses), bunch length, reproducibility, long & medium term stability, current & phase jitter – especially for factor 8
- It’s a goal in itself, but will also ease all other experimental goalsImprove existing feedbacks, develop & deploy new onesincrease beam repetition rateCorrect/cross-calibrate BPMs, improve DB phase diagnostics (BPRs, phase monitors)
TBTSPETS on/off:
Measure break-down rates in different conditions (recirculation high-power, nominal on and off)New accelerating structure with wakefield monitorsBD measurements & BD kicks measurements, wake-field monitor testsRF pulse shaping tests
TBLRF power production: 12 to 13 PETS tanks, from 20 A to 30 Afurther improve precision of current, energy, bunch length & RF power measurementsReach more than 1/3 decelerationDrive beam phase stability monitoring
TERA run for medical accelerator testPHIN photoinjector tests
08/03/12
Frank Tecker
2012/13 - BDR with beam loading
Beam loading reduces field => BDR lower?CLEX probe beam has only low current=> use CTF3 drive beam and klystron driven X-band structurereactivate the old ‘30 GHz PETS’ line
CLEX
DRIVE BEAM LINAC
DELAY LOOP
COMBINER RINGBL - BDR
experiment
Frank TeckerCTF3 - IEFC Workshop 2012
CTF3 plans for 2013+ - TBL+12 PETS installed start 2012Improve Drive Beam quality for combination 8in 2012 (emittance, bunch length, stability)Study deceleration, power production, and beam stability16 PETS installed late 2012
Upgrade TBL to a test facility relevant for CLIC TDR work
12 GHz power production for structure conditioning and component testingWorking experience with a real deceleratorBeam dynamics studies, pulse shaping, feedbacks, etc.
Timeline:Last batch of four PETS installed in late 2012 will be adapted to high-power testingOne (or two) slots tested at beginning of 2013Gradual increase to 4-8 slots and higher rep rate
08/03/12
PETS tank
Accelerating structure under test Beam
RF
S. Doebert
Frank TeckerCTF3 - IEFC Workshop 2012
CTF3 plans 2013+ - Two-beam modulesTests of a series of full-fledged Two-Beam Accelerator modules with beamTests of RF, beam instrumentation, cooling, alignment, etc. in real accelerator environmentFirst module in CLEX TBTS in 2013Three modules types foreseen for 2014
08/03/12
3D model of integration of the first CLIC Module in CLEX (2013)
CLEX - Three two-beam modules(2014)
G. Riddone
Schematic layout of T0 module
Drive beam
Probe beam
Frank TeckerCTF3 - IEFC Workshop 2012
Phase monitor
DRIVE BEAM LINAC
CLEXCLIC Experimental Area
DELAY LOOP
COMBINERRING
10 m
Phase & energy measurement
Fast feed-forward kicker in final
compression line
CTF3 - Phase feed-forward
Phase monitor
Stripline kicker
P. Skowronski,P. Burrows, A.Ghigo
Fast kickers
CLIC drive beam phase feed-forward concept
Drive Beam feed-forward and feedback
Show principle of CLIC fast feed-forwardSeries of related studies at CTF3 to measure phase and energy jitter, identify sources, devise & implement cures, extrapolate to CLICPhase monitor tests in 2012First feedback/feed-forward tests in 2013Close link to collaborating partners(INFN, Oxford…)
08/03/12
Frank TeckerCTF3 - IEFC Workshop 2012
2013 - CTF3 operation wish listBeginning March: water, electrical systems, CO, etc. for HW testsBeginning April: start with beamMid December: Beam stop
During operation CTF3 normally uses the resources of:Piquet ControlFirst line PO
Both not absolutely essential for CTF3 operation (at expense of efficiency) Best effort service from specialist has been done for limited time in the past
RP controlsAccess control
Discussion started how this can be doneCCC for night and weekend supervision
Can be droppedOccasionally EN/CV for water stations and some vacuum support
08/03/12
Frank TeckerCTF3 - IEFC Workshop 2012
SummaryVery good progress in 2011 through many improvements
>250 MW produced in PETSup to 145 MV/m acceleration19A beam decelerated by ~25%, >0.5 TW RF power producedPETS ON/OFF mechanism verified
Main goals in 2012improve beam quality in particular for factor 8 combinationdeceleration studies with 12/13 PETS in TBLBreakdown rate measurements for PETS ON/OFFAccelerating structure test with wakefield monitors in TBTScontinue breakdown kick and breakdown rate studies
Further planningincrease beam energy and repetition ratemeasure breakdown rate with beam loadingstudy CLIC two-beam modulesupgrade TBL to an RF testing facilityimplement a phase feed-forward for the drive beam
08/03/12