Performance simulation and design of the magnetic bunch compressor for the infrared free-electron laser at the Pohang light source test linac

A chicane bunch compressor was designed for the infrared free-electron laser project at the Pohang Light Source test linac. The bunch compressor has triplet quadrupoles before and after the chicane to obtain a transversely uncorrelated beam at the center of the bunch compressor. In this paper, we describe the design considerations of the chicane that provides a compression from 3 ps rms to 250 fs rms a beam energy of 100 MeV. Simulations provide predictions of emittance variation with the chicane parameters and the linac RF phase in the precompressor. The simulations also indicate that the normalized emittance in the designed bunch compressor increases from 5 mm mrad to about 5.5 mm mrad.