Beam loading effects and microwave instability in the booster ring of a high intensity heavy-ion accelerator facility

Abstract

Transient beam loading effects and microwave instability are very important in ion synchrotrons. A simulation code longitudinal particle tracking code (LPTC) based on multiparticle tracking is developed to simulate the beam loading effects and the longitudinal beam instabilities in the booster ring (BRing) of the High Intensity heavy-ion Accelerator Facility (HIAF). A process of beam capture, acceleration, debunching, and the second capture is simulated with a reference ion beam of ^{78}Kr^{19+}. The simulation results show that the beam loading effects have major contribution to the beam behavior during the debunching stage and the second capture stage. A feed-forward system is suggested to compensate the beam loading effects, and the main parameters of the feed-forward system are given. The microwave instability of coasting ^{78}Kr^{19+} beams is observed from the simulation results. The threshold of the microwave instability is also given. The development of self-bunching and methods to suppress the microwave instability in the BRing are discussed.