Multiplexed photoinjector optimization for high-repetition-rate free-electron lasers

Abstract

The multiplexing capabilities of superconducting X-ray free-electron lasers (FELs) have gained much attention in recent years. The demanding requirements for photon properties from multiple undulator lines necessitate more flexible beam manipulation techniques to achieve the goal of “beam on demand”. In this paper, we investigate a multiplexed configuration for the photoinjector of high-repetition-rate FELs that aims to simultaneously provide low-emittance electron beams of different charges. A parallel, multi-objective genetic algorithm is implemented for the photoinjector parameter optimization. The proposed configuration could drastically enhance the flexibility of beam manipulation to improve multiplexing capabilities and realize the full potential of the facility.

The LCLS-II Photoinjector Laser Infrastructure

“…However, even with this reduced conversion efficiency, we were able to meet the final power specification on the cathode (see Table I, ~0.1 W). For the future improvement of the conversion efficiency, we are considering various nonlinear conversion approaches, including noncollinear sum frequency generation [59][60][61] and four-wave mixing in a gas-filled hollow-core fiber [62].…”