随着科学技术的发展和人民生活水平的提高,一系列先进的医疗设备不断出现并被很快地投入医学临床使用之中,其中最有代表性的就是放射性医学诊断与治疗设备。这些放射性诊疗设备的广泛使用,使得人们接受放射诊疗的频率与人数均有明显的增加。密封放射源是目前使用最广泛的γ射线源之一,一般是人工放射性核素。该类密封放射源具有如下特点:1)具有较强的穿透能力;2)具有相对较长的半衰期,可避免频繁地更换和补充源,保 With the development of science and technology and the improvement of people’s living standard, a series of advanced medical equipment emerge and are rapidly put into medical clinical use. Among them, the most representative is the radiological medical diagnosis and treatment equipment. The widespread use of these radiological diagnostic equipment has led to a significant increase in the frequency and number of people receiving radiotherapy. Sealed radioactive sources are currently one of the most widely used sources of gamma rays, usually artificial radionuclides. Such sealed radioactive sources have the following characteristics: 1) has a strong penetrating ability; 2) has a relatively long half-life, to avoid frequent replacement and replenishment of the source