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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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0

1

2

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5

6

-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

0

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

5

6

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

40

45

50

55

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.