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Electron Source Simulations for the ILC

Manu LakshmananCornell University

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ILC Electron Source

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Our Simulations• Electron Gun

• Solenoidal Field to focus beam

• First Subharmonic Buncher (SHB-I)

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Photocathode Electron Gun

AI 105

3VKI

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Beam without solenoidal field

nst 160

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Solenoidal field used to focus beam

)(mz

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BunchingT/4

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Simulations of parametersGun bias voltage

140-200kV Initial time pulse length

500ps-1ns

SHB field strength

z

leE

cmL

z

erf

2

332

Focal length w/o space charge

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Bunching as a function of field strength, zE

SHB-I

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SHB-I field strength, needed to compress bunch to 577 ps

Electron Gun Bias Voltage,

140 160 180 200

500 7.58 6.92 8.03 11.12

630 7.46 8.19 8.36 12.06

760 7.66 6.48 7.59 7.81

890 7.20 9.28 7.03 8.69

1020 5.64 6.04 6.83 8.17Initi

al t

ime

pu

lse

len

gth

, mMVEz

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Conclusions and future work

• Modest gun bias voltage (~140 kV) is sufficient.

• The possibility of using one SHB instead of two should be investigated.

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Acknowledgements

• Dr. Axel Brachmann

• SULI Program