质子束轰击探测器产生的感生放射性核素，将使探测器成为一个典型的外照射辐射源，针对感生放射性核素种类、活度的计算有利于辐射防护工作的开展。使用FLUKA蒙特卡罗程序，研究了低能质子束(20 MeV以内)轰击三种探头材料(铜、钽、钨)产生的感生放射性问题，得到探头材料在一定照射时间下的放射性核素活度及指定冷却时间后的剂量水平。研究结果表明，质子束轰击铜探头产生感生放射性的能量阈值最低(4~5 MeV)，而钨、钽探头与质子束产生感生放射性的能量阈值较高。相同照射时间下的钨、钽探头产生感生放射性总活度远低于铜探头，在冷却1 h后其放射性总活度降至最低。

Induced radionuclides in probe bombarded with proton beam will turn the detector into a typical external irradiation radiation source. It is beneficial for developing radiation protection to calculate the kinds and the activity of induced radionuclides. Here, the induced radioactivity for three types of probe materials (Cu, Ta and W) irradiated by low-energy (below 20 MeV) proton beam are separately simulated the FLUKA Monte-Carle program. The results show that the energy threshold of induced radioactivity in the copper probe is the lowest (about 4-5 MeV) compared with those in the tungsten and tantalum probes (about 10 MeV). In addition, the total induced radioactivity of the copper probe is always higher than the other two under the same irradiation time with decay time up to 1 hour.