The study focuses on the investigation of induced radioactivity resulting from the operation of a proton therapy accelerator which poses an enduring risk to both staff and the public. Therefore, it is imperative to conduct research on this topic. The Monte Carlo code FLUKA is utilized to study the residual dose rate of a 250 MeV proton therapy accelerator under various operational and cooling durations, as well as the types and specific activities of radionuclides produced in the structural components, concrete walls, cooling water, cooling water pipe, soil, and underground water. The findings indicate that after continuous operation for 100 days followed by a 1-h cooling, the residual dose rate at the distance of 30 cm from the surface of the structural components is 0.98 mSv/h. At this point, maintenance personnel can safely enter the hall. During emergency equipment maintenance after shutdown, it's advised to keep maintenance personnel at least 1 m away. After 30 years, cooling water, soil, and underground water meet exemption requirements. Air and concrete walls necessitate cooling for 30 min and 3 days, respectively. Directly exemption cannot be granted for metal components due to long-lived nuclides present in these materials, such as Co which takes over several years to decay to safe levels. Consequently, highly activated metal components require remote disassembly and storage.

中文翻译：

---

质子治疗加速器中诱导放射性的研究

该研究的重点是调查质子治疗加速器运行所产生的诱发放射性，这对工作人员和公众都构成了持久的风险。因此，开展这一课题的研究势在必行。利用蒙特卡罗代码 FLUKA 研究 250 MeV 质子治疗加速器在不同运行和冷却持续时间下的残余剂量率，以及结构部件、混凝土墙、冷却水、冷却系统中产生的放射性核素的类型和比活度。水管、土壤和地下水。研究结果表明，连续运行100天并冷却1h后，距结构件表面30cm处的残余剂量率为0.98mSv/h。此时，维护人员即可安全进入大厅。设备停机后紧急维护时，建议维护人员距离至少1m。 30年后，冷却水、土壤和地下水满足豁免要求。空气墙和混凝土墙分别需要冷却 30 分钟和 3 天。金属部件不能直接获得豁免，因为这些材料中存在长寿命核素，例如钴，需要数年时间才能衰变到安全水平。因此，高度活化的金属部件需要远程拆卸和存储。