| Paper |
Title |
Page |
| MOP25 |
The LEBRA 125 MeV Electron Linac for FEL And PXR Generation
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90 |
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- K. Hayakawa, Y. Hayakawa, K. Ishiwata, K. Kanno, K. Nakao, T. Sakai, I. Sato, T. Tanaka
LEBRA, Funabashi
- K. Yokoyama
KEK, Ibaraki
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A 125 MeV electron linac has been constructed at Laboratory for Electron Beam Research and Application (LEBRA) in Nihon University for Free Electron Laser (FEL) and Parametric X-ray (PXR) generation. Two klystrons feed rf power of approximately 20 MW peak and 20 μsec pulse duration each to an injector and three 4 m accelerating structures. Phase of the rf fed to each component is controlled independently. Two accelerating structures connected with the second klystron and a ninety degrees bending system as a momentum analyzer constitute a magnetic bunching system. Electron bunches of 3 to 4 psec width formed at the injector are compressed to within 1 psec during passing through the magnetic bunching system. Peak current of the electron beam injected to the FEL system installed downstream of the momentum analyzer is expected to be about 50 A. FEL lasing has been achieved at the wavelength range from 1 to 6 mm. Estimated peak power of the extracted FEL light pulse is about 2 MW. Applied researches using the FEL started last autumn. Preliminary experiment for the PXR generation has been continued.
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| MOP31 |
Development of a C-band Accelerating Module for SUPERKEKB
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108 |
| |
- S. Ohsawa, M. Ikeda, K. Kakihara, T. Kamitani, T. Oogoe, T. Sugimura, S. Yamaguchi, K. Yokoyama
KEK, Ibaraki
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High power rf processing of 1 m C-band accelerating section for Super KEKB was successfully performed and power corresponding to 42 MV/m was achieved. Processing data were accumulated including acoustic sensor to find the arcing position. No structural damage was observed from the phase shift measurement performed after the processing. Processed accelerator was installed in the beam line of KEKB linac and being re-processed. The beam acceleration of 40 MV/m was successfully achieved in October 2003. Present status of C-band accelerator development is reported.
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| TUP64 |
Bunch Length Measurements at LEBRA
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411 |
| |
- K. Yokoyama
KEK, Ibaraki
- K. Hayakawa, Y. Hayakawa, K. Nakao, I. Sato, T. Tanaka
LEBRA, Funabashi
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The bunch length of the electron beam from the FEL linac at LEBRA (Laboratory for Electron Beam Research and Application) was estimated from the phase ellipse coefficient which is deduced from the dependence of the beam spread on the accelerating phase. The bunch length of FWHM was estimated approximately 0.33 mm from the results of the experiments. Besides, the pulse length of the FEL lights around the wavelength of 1.5 μm was measured by means of the autocorrelation. The pulse length was less than 0.06 mm according to the number of interfacial waves. These results indicate that the pulse length of the FEL lights isn’t equivalent to the electron bunch length.
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| THP61 |
SKIP - A Pulse Compressor for SuperKEKB
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754 |
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- T. Sugimura, M. Ikeda, K. Kakihara, T. Kamitani, S. Ohsawa, K. Yokoyama
KEK, Ibaraki
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An upgrade of KEKB injector linac is planned. A main purpose of this upgrade is to increase injection energy of positrons from 3.5 GeV to 8.0 GeV for the SuperKEKB project. By a limitation of land area, our choice is to double an acceleration field utilizing a C-band accelerator structures instead of present S-band structures. Last year we developed C-band components such as accelerator structure, dummy load, 3 dB hybrid coupler, RF window, sub booster, modulator system, and so on. These components were assembled at a test stand and processed. This accelerator unit was installed in the beam line of injector linac and has been under operation. This summer we will install an RF pulse compressor system to the C-band accelerator unit. This paper reports the status of development of the RF pulse compressor system.
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| THP29 |
Development of C-band Accelerating Section for SuperKEKB
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663 |
| |
- T. Kamitani, N. Delerue, M. Ikeda, K. Kakihara, S. Ohsawa, T. Oogoe, T. Sugimura, T. Takatomi, S. Yamaguchi, K. Yokoyama
KEK, Ibaraki
- Y. Hozumi
GUAS/AS, Ibaraki
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For the luminosity upgrade of the present KEK B-factory to SuperKEKB, the injector linac has to increase the positron acceleration energy from 3.5 to 8.0 GeV. In order to double the acceleration field gradient from 21 to 42 MV/m, design studies on C-band accelerator module has started in 2002. First prototype 1-m long accelerating section has been fabricated based upon a design which is half scale of the present S-band section. High power test of the C-band section has been performed at a test stand and later at an accelerator module in the KEKB injector linac. In a beam acceleration test, a field gradient of 41 MV/m is achieved with 43 MW RF power from a klystron. This paper report on the recent status of the high-power test and also the development of a second prototype section.
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