球载大面积Phoswich能量分辨率研究

Research in the Energy Resolution of Balloon Borne Large Area Phoswich Detectors

对混合型球载硬Ｘ射线天文望远镜（ＨＡＰＩ－４）的ＰｈｏｓｗｉｃｈＮａＩ（Ｔｌ）／ＣｓＩ（Ｎａ）探测器的能量分辨率进行了研究。实测表明，光电倍增管光阴极面响应的非均匀性与入射光谱有关，用蓝色滤光片所测非均匀性小于２０％。采用对晶体窗玻璃进行罩膜处理，改变荧光收集条件，以牺牲幅度换取均匀性对能量分辨率的改善效果是十分明显的，可将Ｐｈｏｓｗｉｃｈ探测器能量分辨率从４５％（６０ｋｅＶ）提高到２４％。此外，对几种光学耦合材料也进行了测量比较。

We have done some researches in the energy resolution of Phoswich (NaI(Tl)/CsI(Na)) detectors, a main instrument of HAPI 4 Balloon borne Hybrid Hard X ray Astronomy Telescope. It shows that the non uniformity of PMT photocathode response depends on the incident spectra. It's obvious to improve the energy resolution from 45% to 24% ( 60 keV) by using special masks at the expense of reducing the signal amplitude.