CERN Accelerating science

Article
Title	A Multistage HGHG-Scheme for the BESSY Soft X-ray FEL Multiuser Facility
Author(s)	Krämer, Dietrich
Affiliation	(BESSY GmbH, Berlin)
Publication	2004
In:	26th International Free Electron Laser Conference and 11th FEL User Workshop 2004, Trieste, Italy, 29 Aug - 3 Sep 2004, pp.e-proc. MOPOS04
Subject category	Accelerators and Storage Rings
Abstract	BESSY recently finalized the Technical Design Report for a multi-user FEL-facility in the VUV to soft X-ray spectral range. A cascaded HGHG-approach has been adopted, allowing to generate stable, reproducible multi-GW pulses at selectable pulse duration down to <20 fs. Three independent FEL-lines with three beamlines each are proposed. The FELs are driven by a most flexible superconducting CW linac based on the TESLA 9-cell cavities[1]. 18 modules of 8 cavities are needed to accelerate the beam to a final energy of 2.3 GeV at a modest field of < 16 MV/m. A 1 kHz repetition frequency rf-photoinjector, similar to the PITZ-gun [2], will be used in the beginning, to be replaced later on by a CW-photoinjector to produce arbitrary pulse patterns as needed by the experimenters. A summary of the project plans and present activities will be given.