Speaker
Description
FLASH is an XUV and soft X-ray free-electron laser (FEL) facility that contains a superconducting linear accelerator with a beam energy of up to 1.35 GeV which drives two FEL beamlines in parallel and a plasma wakefield accelerator experiment called FLASHForward. Within the upgrade program FLASH2020+, a laser heater was installed upstream of the first bunch compression chicane to mitigate microbunching instability in the linear accelerator by a controlled increase of the uncorrelated energy spread. The effect of the laser heater on microbunching instability and final energy spread has been verified with a transverse deflecting cavity. In this paper, we describe the layout of the laser heater, including the dedicated high repetition rate laser system, and report on improved operational aspects. It has been shown that the laser heater eliminates coherent contributions to visible transition radiation in transverse beam size measurements and thus contributes to better electron beam matching. In addition, an increase in the FEL output power is demonstrated, especially for first operation of the 3rd harmonic afterburner with variable polarisation.
| Region represented | Europe |
|---|---|
| Paper preparation format | LaTeX |
