CERN Accelerating science

Article
Title	Synchronizaiton Between Laser and Electron Beam at Photocathode RF Gun
Author(s)	Sakumi, Akira ; Dobashi, Katsuhiro ; Fukasawa, Atsushi ; Kumagai, Noritaka ; Muroya, Yusa ; Tomizawa, Hiromitsu ; Ueda, T ; Uesaka, Mitsuru ; Urakawa, Junji ; Yoshii, K
Affiliation	(JASRI/SPring-8, Hyogo) ; (KEK, Ibaraki) ; (NIRS, Chiba-shi) ; (UTNL, Ibaraki)
Publication	2005
In:	21st IEEE Particle Accelerator Conference, Knoxville, TN, USA, 16 - 20 May 2005, pp.3079
Subject category	Accelerators and Storage Rings
Abstract	The chemical reactions of hot, room temperature and critical water in a time-range of picosecond and sub-picosecond have been carried out by the 18 MeV S-band linac and a Mg photocathode RF gun with the irradiation of third harmonic Ti: Sapphire laser, at Nuclear Engineering Research Laboratory (NERL), the University of Tokyo. Although this short bunch and 100 fs laser light are enough to perform the experiment of radiation chemistry in the time-range of sub-picosecond, the total time-resolution become worse by the instability of synchronization between laser and radio frequency of linac. We found that the fluctuation of room temperature causes the instability, particularly the cycle of turning on/off of the air-conditioner. It is shown that 0.3 °C (peak-to-peak) fluctuation of the laser-room temperature have approximately corresponded to the instability of 6 ps. We are trying to decrease the fluctuation of the room temperature, together with the local temperature stability of the Ti: Sapphire crystal, the pumping laser. Furthermore, we will develop the feed back system for reducing the instability of the synchronization.