CERN Accelerating science

Article
Title	Recent Results from and Future Plans for the VISA II SASE FEL
Author(s)	Andonian, Gerard ; Agustsson, Ronald ; Babzien, Marcus ; Ben-Zvi, Ilan ; Boscolo, Ilario ; Cialdi, Simone ; Ferrario, Massimo ; Flacco, Alessandro Federico ; Frigola, Pedro ; Huang, Jung Y ; Litvinenko, Vladimir N ; Murokh, Alex ; Palumbo, Luigi ; Pellegrini, Claudio ; Reiche, Sven ; Rosenzweig, James E ; Travish, Gil ; Vicario, Carlo ; Yakimenko, Vitaly
Affiliation	(BNL, Upton, Long Island, New York) ; (INFN-Milano, Milano) ; (INFN/LNF, Frascati (Roma) ; (PAL, Pohang) ; (UCLA, Los Angeles, California)
Publication	2005
In:	21st IEEE Particle Accelerator Conference, Knoxville, TN, USA, 16 - 20 May 2005, pp.2167
Subject category	Accelerators and Storage Rings
Abstract	As the promise of X-ray Free Electron Lasers (FEL) comes close to realization, the creation and diagnosis of ultra-short pulses is of great relevance in the SASE FEL (Self-Amplified Spontaneous Emission) community. The VISA II (Visible to Infrared SASE Amplifier) experiment entails the use of a chirped electron beam to drive a high gain SASE FEL at the Accelerator Test Facility (ATF) in Brookhaven National Labs (BNL). The resulting ultra-short pulses will be diagnosed using an advanced FROG (Frequency Resolved Optical Gating) technique, as well as a double differential spectrum (angle/wavelength) diagnostic. Implementation of sextupole corrections to the longitudinal aberrations affecting the high energy-spread chirped beam during transport to the VISA undulator is studied. Start-to-end simulations, including radiation diagnostics, are discussed. Initial experimental results involving a highly chirped beam transported without sextupole correction, the resulting high gain lasing, and computational analysis are briefly reported.