Analysis of Higher Order Modes of the Superconducting Cavities for the China-ADS Injector-II in IMP

The influence of the higher order modes on the beam dynamics and the cryogenic losses has been studied for the superconducting half wave resonators of the China ADS in this paper. In addition, the necessity of HOM dampers in the Superconducting (SC) cavities is discussed. INTRODUCTION The Accelerator Driven System for nuclear waste transmutation of China (China ADS) is a high intensity CW proton beam facility which is based on the superconducting accelerating structure with the design specifications of 10 mA beam current and 25 MeV based on the half wave resonator (developed by Institute of Modern Physics) and spoke cavities (developed by Institute of High Energy Physics) [1]. In this work, two types of half wave resonator cavities (f=162.5MHz, βopt=0.10, 0.15 [2]) of IMP have been investigated for their possible dangerous HOMs.