多像素光子计数器的能量分辨性能测试

Energy resolution performance testing for mulit-pixel photon counter

随着新型光电转换器件技术的快速发展,多像素光子计数器(Multi Pixel Photon Counter,MPPC)逐渐被应用到核辐射探测等相关领域。本文将MPPC分别与碘化铯(Cs I)、碘化钠(Na I)以及锗酸铋(Bi4Ge3O12,BGO)闪烁晶体进行光学耦合,测量137Cs、60Co两种γ射线放射源的三个特征峰的能谱,测试结果与光电倍增管(Hamamatsu H7195)和闪烁晶体耦合所测得的结果进行了对比。此外,用自制的前置放大器与波形数字采样器(CAEN DT5730)对MPPC的输出信号进行了采集测试。结果表明:MPPC相比于光电倍增管,其能量分辨率稍差,但是具有相当的能量线性。

[Background] With the development of semiconductor photon detector technology, a novel signal readout device named multi pixel photon counter （MPPC） has gradually been developed and applied in radiation detection. [Purpose] This study aims to verify the performance of the MPPC and compare it with photomultiplier tube （PMT） in linearity and energy resolution. [Methods] First of all, scintillation detectors with MPPC coupling with scintillation crystals such as thallium-doped sodium iodide （NaI（T1））, CsI, and Bi4Ge3012 （BGO） crystals was constructed to test three characteristic T-ray energy peaks of 137Cs and 60Co. Then the same tests were done with PMT （Hamamatsu H7195） coupling with these crystals as the parallel experiments. Simultaneously, the output signal of the MPPC was collected by using a waveform digitizer （CAEN DT5730） and a self-made pre-amplifier. [Results] The results show that the MPPC has a slightly worse energy resolution compared to that of PMT, but reserves a similar energy linearity. [Conclusion] This MPPC could be applied in circumstances such as the space detection and medical applications instead of PMT.