Beam dynamics studies of the photo-injector in low-charge operation mode for the ERL test facility at IHEP

TL;DR

This study optimizes the beam dynamics of a photo-injector in a low-charge mode for an ERL test facility, analyzing sensitivities and tolerances to improve beam quality.

Contribution

It presents the first detailed optimization and analysis of beam dynamics for a low-charge photo-injector in an ERL test facility using Impact-T simulations.

Findings

Optimized beam parameters for low-charge operation.

Identified sensitivities to initial offsets and element parameters.

Analyzed alignment and rotation error tolerances.

Abstract

The energy recovery linac test facility (ERL-TF), a compact ERL-FEL (free electron laser) two-purpose machine, was proposed at the Institute of High Energy Physics, Beijing. As one important component of the ERL-TF, the photo-injector started with a photocathode direct-current gun has been designed. In this paper optimization of the injector beam dynamics in low-charge operation mode is performed with iterative scans using Impact-T. In addition, the dependencies between the optimized beam quality and the initial offset at cathode and element parameters are investigated. The tolerance of alignment and rotation errors is also analyzed.