# Systematical design and three-dimensional simulation of X-ray FEL oscillator for Shanghai Coherent Light Facility

## TL;DR

This paper presents the design, parameter optimization, and 3D simulation of an X-ray FEL oscillator for the Shanghai Coherent Light Facility, utilizing a new diffraction code BRIGHT for performance analysis.

## Contribution

It introduces a comprehensive design framework and a novel 3D diffraction simulation code for XFELO, tailored for the SCLF facility.

## Key findings

- Optimized undulator and cavity parameters for SCLF XFELO.
- Demonstrated feasibility of XFELO operation at SCLF.
- Enhanced understanding of XFELO performance through simulation.

## Abstract

Shanghai Coherent Light Facility (SCLF) is a quasi-CW hard X-ray free electron laser user facility which is recently proposed. Due to the high repetition rate, high quality electron beams, it is straightforward to consider an X-ray free electron laser oscillator (XFELO) operation for SCLF. The main processes for XFELO design, and parameters optimization of the undulator, X-ray cavity and electron beam are described. The first three-dimensional X-ray crystal Bragg diffraction code, named BRIGHT is built, which collaborates closely with GENESIS and OPC for numerical simulations of XFELO. The XFELO performances of SCLF is investigated and optimized by theoretical analysis and numerical simulation.