美国ORTEC公司的正电子寿命系统采用快—快符合电路组装,和快—慢符合电路相比,具有结构简单,可使用较强的源,测谱时间短等优点。我们购置的一台ORTEC正电子寿命系统,自去年年底在上海复旦大学验收以后,较长一段时间内都在由厂方确定的工作状态下进行工作。虽然该仪器自动化性能较高,使用方便,也有较好的时间分辨率(表1中*);但是在计数率方面不理想,用10μCi的~(60)Co源测仪器的时间分辨率和用50μCi的~(22)Na点源测材料的寿命谱,测量时间都较长(表1中*,表2中RT_1)没有发挥快—快符合的优点。为此,我们又对仪器的工作状态进行了一些调试,尤其对甄别器的能窗作了多种设置,从中选出一种既能 ORTEC’s positron lifetime system uses fast-fast circuit assembly, fast and slow circuit compared with the simple structure, the source can be used more strong, short time spectrum measurement. We purchased an ORTEC positron lifetime system, which has been in working condition determined by the manufacturer for a long period of time since the end of last year was accepted by Shanghai Fudan University. Although this instrument has high automation and easy to use, it also has better time resolution (* in Table 1); however, it is not ideal in terms of counting rate. The time resolution of a 60Co source with 10μCi The lifetime spectrum of the 50μCi ~ (22) Na point source material did not exhibit the fast-fast coincidence with the longer measurement time (Table 1 *, RT_1 in Table 2). For this reason, we have carried on some debugging to the working condition of the instrument, especially made a variety of settings on the energy window of the discriminator,