摘要: 加速器驱动次临界系统C-ADS 注入器Ⅱ采用强流超导质子直线加速器，设计流强达到10 mA。强流质子束产生的束流损失有可能损伤超导腔，需要专用的束流损失监测系统进行监测，束流损失探测器(BLM) 需要在高能量沉积导致超导腔失超之前提供警报。通过MCNPX 模拟计算10 MeV 质子在半波谐振腔(HWR)不同位置损失产生的辐射场，比较选取超导腔管道进出口处4 个位置为推荐束损探测器放置的位置，结合HWR腔结构和束损探测器选择的影响因素，计算了次级辐射在金刚石探测器中的能量沉积以及1° ~ 5°不同质子入射角度对探测的影响。结果表明，根据不同位置处探测器的能量沉积关系可以推断出束损点；不同入射角度不会影响生成粒子的能量分布，只轻微影响生成粒子的数目。

The Chinese Accelerator Driven Subcritical System (C-ADS) injector II consists of super-conduction accelerating section which is half wave resonator (HWR), the designed beam intensity is 10 mA. To avoid the damage to the resonator due to proton beam loss, special Beam Loss Monitor (BLM) system is essential. BLM system could provide alarm signal when high energy deposition occurs which may cause the resonator quenching. Radiation field of 10 MeV proton lost at different point of the HWR are simulated with MCNPX, BLM could be set at proper positions based on the simulation. Considering the structure of HWR and the BLM detector selecting influence factor, radiation energy deposition in the diamond detector are simulated with MCNPX when the proton incidence angle change from 1°  5°, Possible beam loss point can be deduced from the relationship of energy deposition in detectors at different locations. The results indicate that energy spectra of secondary particles are independent with incidence angle; the number of secondary particles may be influenced slightly.