CERN Accelerating science

Article
Title	Experimental Observation of a 100-Femtosecond Single Electron Bunch in Photocathode Linac with Longitudinal Emittance Compensation Technique
Author(s)	Yang Jin Feng ; Kan, K ; Kondoh, Takafumi ; Kozawa, Takahiro ; Tagawa, Seiichi ; Yoshida, Yoichi
Affiliation	(ISIR, Osaka) ; (RCNP, Osaka)
Publication	2005
In:	21st IEEE Particle Accelerator Conference, Knoxville, TN, USA, 16 - 20 May 2005, pp.1546
Subject category	Accelerators and Storage Rings
Abstract	The realization of a 100fs electron pulse is important for the studies of ultrafast physical/chemical phenoena with a pump-probe method. We have developed a photocathode linear accelerator (linac) to generate such electron pulse with a magnetic pulse compressor. The nonlinear effect of the magnetic fields in the pulse compression was compensated carefully by optimizing the magnetic fields and the booster linac RF phase. A 105fs(rms) electron bunch with electron charge of 0.1nC was observed experimentally by using a femtosecond streak camera. The beam energy was 35MeV, and the normalized teraservers emittance was lower than 3mm-mrad. The dependences of the pulse length and the emittance on the electron charge were also measured and compared with the theoretical calculations.