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1
Plans for KEK/ATF
1. Introduction2. Related Instrumentations at ATF3. Experimental Plans for Fast Kicker
R&D at ATF
Junji Urakawa (KEK) at ILC Damping Rings R&D Workshop – ILCDR06, Cornell University
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-5 10-9 0 5 10-9 1 10-8
FID(FPG-3000M) Waveform
Vol
tage
(kV
)
Time(s)
Pulse generator
Specifications
Amplitude at 50 ohm : 5 kVRise time : 1-1.4 nsPulse width at 50% of amplitude : 2-3 nsMaximum Pulse Repetition Frequency in burst mode : 3 MHz
FID Technology has very fast and high repetition rate pulse generators. The specification meets our requirements for the high voltage pulse source. We tested the kicker performance by using the pulse PS.
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Beam kick experiment at ATF DR
The kicker pulse is applied to the strip-line electrode when the beam goes through the electrode.The beam kick is observed by a turn-by-turn BPM as the amplitude of the oscillation of the betatron frequency component.The kick effect is measured by scanning the pulse timing precisely.
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Measurement result of FPG5-3000MThe achieved resolution is 0.2rad.
Rise time~3.2nsKick angle ~91rad(calc. 94.7rad)
Expanded horizontal scale
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20
40
60
80
100
10 12 14 16 18 20
Pulse timing v.s. kick angle(FID FPG-3000M)
Kic
kAng
le(u
rad)
Delay(ns) Time
0
20
40
60
80
100
0 5 10 15 20 25 30
Pulse timing v.s. kick angle(FID FPG-3000M)
Kic
kAng
le(u
rad)
Delay(ns) Time
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After tuning of the circuit,
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ATF Introduction
E=1.3GeV, Ne=3x1010 e-/bunch 1 ~ 20 bunches, Rep=3.125HzX emit=2.5x10-6( at 0 intensity)
Y emit=1.0x10-8( at 0 intensity)
-2.5x10-9 in Future
Emittance status
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ATF Damping Ring BPM
referenceplane
referenceplane
EBW
referenceplane
19.5 mm
ceramics
button (SUS304)
flange (A3003)HIP transitiontop block (Ti)
SMA connector
pin (Kovar)brazing (Ag-Cu)
brazing (Al)
Button BPM for Damping Ring
ø24mm
70mm
Button electrode assemblycross section of BPM camber
Electronics: single pass detection for 96 BPMs
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Spectrum of DR BPM
Signal peak at ~ 1GHz
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45
50
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60
65
107 108 109 1010
DR
BP
M(M
B30
R)
spec
trum
[dB
V]
Freqency [Hz]
DR button BPM beam signal spectrum out from 40m RG223/u cable
1
10
100
108 109 1010 1011
Est
imat
ed R
esol
utio
n [
m]
Bunch Intensity [electrons/bunch]
Existing circuit(estimated by beam)
Improved circuit(estimated by calibration pulser)
Resolution Improvement
Min. resolution ~ 2µm
Turn by Turn and Bunch by Bunch Signal at 1GHz
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Laser wire beam size monitor in DR
14.7µm laser wire for X scan 5.7µm for Y scan(whole scan: 15min for X,6min for Y)
300mW 532nm Solid-state LaserFed into optical cavity
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Experimental setupExperimental setup
1. laserwire2. detector and collimat
or3. data taking system
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Laserwire setupLaserwire setup
horizontal wire
vertical wire
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DetectorDetector• Compton scattering
28.6 MeV (max gamma energy)23.0 MeV ( 0.2 mrad scattering angle )
• gamma ray detector[70 mm ×70 mm ×300 mm ]
CsI(pure) crystal
2” photo-multiplier
• time resolutionPMT signal leading edge
0.56 nsec resolution
(signal energy region)
enough to separate 2.8ns spacing bunches
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Beam profile by Laser wire
e2 = meas
2 - lw2
= e2 – [(p/p)]2 :measured by Q-trim excitation
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Emittance by Laser wire
< 0.5% y/x emittance ratio
Y emittance =4pm at small intensity
1 10-9
1.2 10-9
1.4 10-9
1.6 10-9
1.8 10-9
2 10-9
0 2 109 4 109 6 109 8 109 1 1010
X emittance by LW
X emittance (single bunch)emitt_x
X e
mit
tanc
e
Bunch Intensity
0.5% coupling Calculation
LW X emit(single 16APR03)0
2 10-12
4 10-12
6 10-12
8 10-12
1 10-11
0 2 109 4 109 6 109 8 109 1 1010
Y emittance by LW
Y emittance (single bunch)Y emittance (15bunch projected)emitt_y
Y e
mit
tanc
eBunch Intensity
0.5% coupling Calculation
LW Y emit(single 16APR03)LW Y emit(15 bunch 6JUN03)
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Beam kick experiment at ATF DR
The kicker pulse is applied to the strip-line electrode when the beam goes through the electrode.The beam kick is observed by a turn-by-turn BPM as the amplitude of the oscillation of the betatron frequency component.The kick effect is measured by scanning the pulse timing precisely.
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Tektronix DPO7254
20GS/s
Powerful Lap-top PCwith huge memory
National Instruments
GPIB- Enet/100
DCCT, ICT
DR Trigger System
DR BPM
Interface to transfer lots of
related data ATF localnetwork
DAQ which will be made soon.
ATF DR tunnel ATF Assembly hall
New powerful data acquisition system
Transverse emittance, bunch length, tune, vacuum level, COD, energy spread, temperature, Acceleration
Voltage
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New powerful data acquisition system will be installed in Nov..
Tektronix, DPO7000, 20GS/sec, 500MHz to 7.25GHz, 1msec continuous signal measurements just after triggeringby the step of 100psec for fast kicker study. (time resolution less than 1psec)
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Experimental Plan for study on fast kicker with multi-bunch
The range from several 109 to 3x1010 electrons/bunchUntil 20 bunches/train, changeable from 1 to 20.Precise emittance growth measurements bunch-by bunch.Accurate beam position measurement during 1msec by thestep of 100psec ; huge data will be obtained.
We will start this R&D from end of Nov. in this year becausenew instrumentation require the check and fine tuning for onemonth from mid. of Oct. and fast kicker R&D has first priority.Anyway, I want to finish this study until 2007 at ATF.
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