Study of non-linear energy response of POLAR plastic scintillators to electrons
Study of non-linear energy response of POLAR plastic scintillators to electrons
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DOI：
10.1016/j.nima.2015.06.031
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发表时间：
2015-10
影响因子：
1.4
通讯作者：
Xiao-Fei Zhang;Hualin Xiao;Boxiang Yu;S. Orsi;Bobing Wu;Wei Hu;Xuan Zhang
中科院分区：
文献类型：
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作者：
Xiao-Fei Zhang;Hualin Xiao;Boxiang Yu;S. Orsi;Bobing Wu;Wei Hu;Xuan Zhang
POLAR实验是一个中欧联合项目，旨在精确测量伽马射线偏振，并优化用于探测能量范围为50-500 keV的伽马射线暴（GRB）的瞬发发射。POLAR是一种新型的紧凑型星载康普顿偏振计，由1600个低Z塑料闪烁体棒（EJ-248 M）组成，由25个平板多阳极光电倍增管读出。本文首先介绍了EJ-248 M塑料闪烁体对电子的非线性能量响应的实验研究和详细的数据分析。其次，通过最小二乘法拟合得到EJ-248 M塑料闪烁体的Birks常数kB= 0.143mm/MeV。最后利用Geant 4仿真研究了非线性能量响应对POLAR性能的影响，发现非线性能量响应会导致统计量显著下降，导致偏振测量的不确定度较大。本文提出了研究塑料陶瓷对电子的非线性能量响应的一般方法。
The POLAR experiment is a joint Chinese-European project conceived for a precise measurement of gamma ray polarization and optimized for the detection of the prompt emission of Gamma-Ray Bursts (GRBs) in the energy range 50–500 keV. POLAR is a novel compact space-borne Compton polarimeter consisting of 1600 low-Z plastic scintillator bars (EJ-248M), read out by 25 flat-panel multi-anode photomultiplier tubes. In the paper, we first present a dedicated experiment to study the non-linear energy response of EJ-248M plastic scintillator bars to electrons and the detailed data analysis. Second we obtained the Birks’ constant of EJ-248M plastic scintillator as kB= 0.143 mm/MeV by least squares fitting. Finally we used Geant4 simulation to study the influence of non-linear energy response on the performance of POLAR, through which it was found that non-linear energy response will lead to a significant decrease in statistics and result in larger uncertainty in polarization measurement. The paper presents a general solution to the study of non-linear energy response of plastic scintillators to electrons.