Theoretical study of the dual harmonic system and its application on the CSNS/RCS

TL;DR

This paper provides a theoretical analysis of the dual harmonic RF system in high-intensity proton synchrotrons, focusing on beam dynamics, potential well, and optimization for CSNS/RCS upgrade.

Contribution

It offers a theoretical investigation of the dual harmonic system's effects on beam dynamics and proposes optimized RF parameters using a new simulation code.

Findings

Analysis of potential well and sub-buckets in the dual harmonic system

Optimization of bunching factor and RF waveform for CSNS/RCS

Simulation results incorporating space charge effects

Abstract

The dual harmonic system has been widely used in high intensity proton synchrotrons to suppress the space charge effect, as well as reduce the beam loss. To investigate the longitudinal beam dynamics in the dual rf system, the potential well, the sub-buckets in the bunch and the multi-solutions of the phase equation have been studied theoretically. Based on these theoretical studis, the optimization of bunching factor and rf voltage waveform are made for the dual harmonic rf system in the upgrade phase of the CSNS/RCS. In the optimization process, the simulation with space charge effect is done by using a newly developed code C-SCSIM.