CERN Accelerating science

Article
Title	Generation of Double-Decker Femtosecond Electron Beams in a Photoinjector
Author(s)	Yang Jin Feng ; Kan, K ; Kondoh, Takafumi ; Kozawa, Takahiro ; Kuroda, Y ; Tagawa, Seiichi ; Yoshida, Yoichi
Affiliation	(ISIR, Osaka)
Publication	2005
In:	21st IEEE Particle Accelerator Conference, Knoxville, TN, USA, 16 - 20 May 2005, pp.1604
Subject category	Accelerators and Storage Rings
Abstract	The femtosecond electron beam is a practical source in the pump-probe experiment for studies of ultrafast physical/chemical reactions in materials, in which a mode-locked ultrashort laser light is used as a probe source. The synchronized time jitter between the electron beam and the laser light limits the time resolution in the experiment. In order to reduce the time jitter, a new concept of synchronized double-decker electron beam generation in a photoinjector was proposed. The double electron beams were observed in an S-band photocathode RF gun by injecting two laser beams which produced with a picosecond laser. The double electron beams were compressed into 400fs(rms) with a phase-space rotation technique in magnetic fields. The beams, which one is used as a pump source and another is used as a probe source, are expected for ultrafast reaction studies in femtosecond resolution.