DESIGN OF CADS INJECTOR-I CRYOMODULE FOR 325 MHz CAVITIES

The Chinese Accelerator Driven Sub-critical system (CADS) uses a high energy proton beam to bombard the metal target and generate neutrons to deal with the nuclear waste. The Chinese ADS proton linear has two 0~10 MeV injectors and one 10~1500 MeV superconducting linac. Injector-I is studied by the Institute of High Energy Physics (IHEP) under construction in the Beijing, China. The linear accelerator consists of two accelerating cryomodules operating at the temperature of 2 Kelvin. This paper describes the structure and thermal performances analysis of the cryomodule. The analysis takes into account all the main contributors (support posts, multilayer insulation, current leads, power couplers, and cavities) to the static and dynamic heat load at various cryogenic temperature levels. The thermal simulation analysis of the cryomodule is important theory foundation of optimization and commissioning. INTRODUCTION The Chinese Accelerator Driven Sub-critical system (CADS) project is based on a proton Linac that provides a10mA, 1.5 GeV CW proton beam for nuclear waste transmutation. The C-ADS linac includes two major sections: the injector section and the main linac section. [1]. The general layout of the linac is shown in Fig. 1. To satisfy the restricted stability and reliability command of the C-ADS driver linac in the lower energy part, there will be two identical Injectors operating in parallel, backing each other up. One of them, Injector I is under design and construction at Institute of High Energy Physics (IHEP), Chinese Academy of Sciences(CAS) [2]. The injector I consists of two accelerating cryomodules (CM1 and CM2), which accelerates proton beam up to 10MeV. One C-ADS cryomodule houses 7 325 MHz Spoke(β =0.12)superconducting cavities, 7 high power couplers, 7 superconducting solenoids, 7Beam Position Monitors( BPM), et al, and the cavities and solenoids will be immersed in a 2K liquid helium bath . ECR LEBT RFQ 162.5MHz HWR 162.5MHz MEBT1 Injector II