A Start-to-End Optimisation Strategy for the CompactLight Accelerator Beamline

The CompactLight collaboration designed a compact and cost-effective hard X-ray FEL facility, complemented by a soft X-ray option, based on X-band acceleration, capable of operating at 1 kHz pulse repetition rate. In this paper, we present a new simple start-to-end optimisation strategy that is developed for the CompactLight accelerator beamline, focusing on the hard X-ray mode. The optimisation is divided into two steps. The first step improves the electron beam quality that finally leads to a better FEL performance by optimising the major parameters of the beamline. The second step provides matched twiss parameters for the FEL undulator by tuning the matching quadrupoles at the end of the accelerator beamline. A single objective optimisation method, with different objective functions, is used to optimise the performance. The sensitivity of the results to jitters is also minimised by including their effects in the final objective function.