| Paper |
Title |
Page |
| WEPLS054 |
Higher-order Effect Compensation in Magnetic Compressor for < 50 fs Electron Bunch Generation
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2502 |
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- K. Kan, T. Kondoh, J. Yang, Y. Yoshida
ISIR, Osaka
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An ultrashort electron bunch is essential for pulse radiolysis, which is a pump-probe measurement based on an ultrashort electron beam and an ultrashort light. In Osaka University, a laser photocathode electron linear accelerator with a magnetic compressor has been constructed for the femtosecond electron bunch generation. An electron beam with bunch length of 98 fs was successfully generated and used in pulse radiolysis. However, an electron beam with bunch length of < 50 fs is required for development of pulse radiolysis with time resolution of 100 fs. To generate such a short bunch, higher order disadvantage effects, which are caused by the fringing fields of the magnets in the compressor, should be compensated. In this paper, a compensation technique of higher-order effects was proposed by using a nonlinear energy modulation in the bunch produced in the linear accelerator by re-phasing the linac away from the zero-crossing of the rf (i.e., away from the linear slope). In the simulation, we compressed the electron bunch into 48 fs at bunch charge of 0.1 nC.
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| WEPLS058 |
Femtosecond Single-bunch Electron Linear Accelerator Based on a Photocathode RF Gun
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2514 |
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- J. Yang, K. Kan, T. Kondoh, A. Yoshida, Y. Yoshida
ISIR, Osaka
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A femtosecond single-bunch electron linear accelerator based on a photocathode rf gun was developed in Osaka University for the study of radiation-induced ultrafast physical and chemical reactions. A 32 MeV single electron bunch with a bunch length of 98 fs in rms was generated successfully in the linear accelerator with a magnet bunch compressor. The dependences of the bunch length and the transverse emittance on the bunch charge were investigated experimentally and theoretically. The higher-order effects in the magnetic field were studied and compensated successfully by using a nonlinear energy-phase correlation in the bunch produced in the linear accelerator. By using the femtosecond electron bunch, an equivalent velocity spectroscopy with a synchronized femtosecond laser, as a new method with femtosecond time-resolution, was developed for study of the ultrafast reactions or phenomena on the femtosecond time scale.
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