Simulation and Analysis of Microphonics Instability of CiADS Superconducting Cavity

To satisfy the high stability requirements of the proton linac for China initiative Accelerator Driven System (CiADS), the influence factors including microphonics for linac stability need to be evaluated at the stage of design. Based on the impulse response model of the resonant system, the discretized iterative algorithm of cavity voltage and corresponsive simulation program were developed in order to analyze the time-varying dynamical process of superconductive cavity under the microphonics. The effect of microphonics on the cavity phase stability, and the relationship between microphonics with cavity parameters, such as resonant frequency, Q value and bandwidth, were simulated. The results show that microphonics mainly effect phase stability of superconducting cavity, and the effect depends on the ratio of the oscillation frequency of microphonics to the resonant frequency of the cavity and the ratio of the frequency shift of microphonics to the half bandwidth of the cavity. The microphonics intensity tolerated by the cavity phase stability requirements (amplitude and phase with 0.1% and 0.1° respectively) of CiADS linac was given.