CAJ | 학술논문

目的调查回旋加速器工作场所辐射剂量水平及其分布状况,以期更好地指导现场人员的防护并为放射性药物生产场所的屏蔽设计提供技术依据.方法以某医院安装的1台HM-20S型回旋加速器及其放射性药物生产场所为研究对象,使用LiF(Mg,Cu,P)热释光剂量计、CR39中子剂量计、NH-1B中子剂量当量率仪和451B剂量巡测仪测量加速器室内中子和γ射线辐射剂量率,并对室外关注点的辐射水平进行验证.结果在质子能量20 MeV、束流100 μA条件下,回旋加速器自屏蔽体南侧表面中子最高剂量率为北侧表面的63倍、γ射线最高剂量率为北侧的6.0倍;机房南墙内表面中子和γ射线剂量率分别为北墙内表面的11倍和5.3倍;机房东墙内表面中子和γ射线剂量率平均值分别为21μSv/h和45 μSv/h,西墙内表面中子和γ射线剂量率平均值分别为34 μSv/h和69 μSv/h.结论回旋加速器室内辐射水平及其分布状况与束流方向和靶位置等因素密切相关,其实测值可用于指导场所的屏蔽设计和人员防护.
목적 조사회선가속기공작장소복사제량수평급기분포상황,이기경호지지도현장인원적방호병위방사성약물생산장소적병폐설계제공기술의거.방법 이모의원안장적1태HM-20S형회선가속기급기방사성약물생산장소위연구대상,사용LiF(Mg,Cu,P)열석광제량계、CR39중자제량계、NH-1B중자제량당량솔의화451B제량순측의측량가속기실내중자화γ사선복사제량솔,병대실외관주점적복사수평진행험증.결과 재질자능량20 MeV、속류100 μA조건하,회선가속기자병폐체남측표면중자최고제량솔위북측표면적63배、γ사선최고제량솔위북측적6.0배;궤방남장내표면중자화γ사선제량솔분별위북장내표면적11배화5.3배;궤방동장내표면중자화γ사선제량솔평균치분별위21μSv/h화45 μSv/h,서장내표면중자화γ사선제량솔평균치분별위34 μSv/h화69 μSv/h.결론 회선가속기실내복사수평급기분포상황여속류방향화파위치등인소밀절상관,기실측치가용우지도장소적병폐설계화인원방호.
Objective Levels and distribution of radiation dose in a cyclotron room were investigated to guide protection of personnel against radiation onsite and provide technical basis for the shielding design of workplaces with radioactive drugs.Methods A cyclotron HM-20S and the room in a hospital where it was installed were investigated.Several LiF (Mg, Cu, and P) thermoluminescence dosimeters, CR39 neutron dosimeters, a neutron dose equivalent rate meter NH-1B, and a dose survey meter 451 B were used to measure the neutron and gamma radiation dose rates in the cyclotron room.Radiation dose levels outside the room were also validated.Results When irradiation conditions were 20 MeV of proton energy and 100 μA of beam current, the maximum neutron dose rate from the southern surface of the self-shielding body of the equipment was 63 times higher than that from northern surface of the self-shielding body.Additionally, the maximum gamma-ray dose rate of the southern surface was 6.0 times higher than that of the northern surface.Neutron and gamma-ray dose rates measured on the inner surface of the southern wall were 11 and 5.3 times higher than those measured on the inner surface of the northern wall, respectively.In addition, mean values of neutron and gamma-ray radiation dose rates from the inner surface of the eastern wall were 21 and 45 μSv/h, correspondingly, whereas those from the western side were 34 and 69 μSv/h, respectively.Conclusion Levels and distribution of radiation dose in a cyclotron room are closely related to several factors, such as beam direction and target position.Radiation dose values measured onsite can be used to facilitate the shielding design of workplaces and provide radiation safety for personnel.