| Paper |
Title |
Page |
| MOPPH077 |
Electron-Linac Based fs-THz Program at Pohang Accelerator Laboratory
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155 |
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- J. Park, H.-S. Kang, C. Kim
PAL, Pohang, Kyungbuk
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A 60 MeV electron linac for the source of coherent fs-THz pulses is under construction at PAL, Korea. The 266 nm pulses provided by the 3rd harmonic conversion of 800nm Ti:Sapphire amplifier system are to be delivered to the photocathode rf-gun. The electron bunches produced from the photocathode rf gun are accelerated and compressed down to several tens of femtosecond in the linac. Then the relativistic electron bunches are used to generate intense fs-THz pulses by coherent transition radiation (CTR). The radiated THz pulses are extracted from the linac vacuum pipe through a CVD diamond window. The beam, which is took up part of the 800nm beam out of the fs-regenerative amplifier, is sent to the THz laboratory to do THz pump-Optical/IR probe experiment.
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| TUPPH019 |
Laser Pulse Shaping for Generation of Low-Emittance Electron-Beam
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278 |
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- C. Kim, Y. W. Parc, J. Park
PAL, Pohang, Kyungbuk
- K. Hyun, I. S. Ko, C. Yim
POSTECH, Pohang, Kyungbuk
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A photocathode RF gun can provides a high-charge short-bunch-length electron beam, so that it can be used for an injector of the 4th generation light source. However, owing to the high-charge in short-bunch-length, generated electron beam experiences severe space-charge effect in the beginning of acceleration and the emittance becomes bad rapidly. To reduce this space-charge effect, we made a preliminary study of pulse shaping technique. First, Parmela simulations are performed to check the beam quality improvement when the plat-top profile laser is used. Given geometry of the photocathode RF gun in the Pohang Accelerator Laboratory, Parmela simulations show 40% decrease of the emittance in electron beams. Next, by stacking four Gaussian pulses to the longitudinal direction, we tried a generation of a plat-top profile laser, and its profile is checked with a cross-correlator.
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