Energy response of GECAM gamma-ray detector based on LaBr3:Ce and SiPM array
Energy response of GECAM gamma-ray detector based on LaBr3:Ce and SiPM array
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DOI：
10.1016/j.nima.2018.12.032
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发表时间：
2019-03-21
影响因子：
1.4
通讯作者：
Zhang, Fan
中科院分区：
文献类型：
--
作者：
Zhang, Dali;Li, Xinqiao;Zhang, Fan
引力波高能电磁对应全天监测（GECAM）是一项新的任务，由两颗小卫星组成，用于监测与引力波（GW）事件同时发生的伽马射线暴（GRBs），视场为100%全天。每颗GECAM卫星使用25个紧凑的新型伽玛射线探测器（grd）在6kv - 5mev中探测和定位grb。每个GRD模块由LaBr3:Ce闪烁体、SiPM阵列和前置放大器组成。通过前置放大器的高增益和低增益通道，实现了大动态范围的GRD。用5.9 ~ 1332.5 keV的辐射源对GRD原型的能量响应进行了评价。在662 keV时，Cs-137脉冲高度光谱的能量分辨率为5.3%，满足GECAM的要求（662 keV时< 8%）。评估能量到信道的转换，并进行非线性校正以减少残差（< 1.5%）。此外，基于geant4的模拟飞行背景和测量的GRD LaBr3:Ce固有活度用于评估飞行校准能力。这些结果证明了GRD的设计。
The Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) , composed of two small satellites, is a new mission to monitor the Gamma-Ray Bursts (GRBs) coincident with Gravitational Wave (GW) events with a FOV of 100% all-sky. Each GECAM satellite detects and localizes GRBs using 25 compact and novel Gamma-Ray Detectors (GRDs) in 6 keV-5 MeV. Each GRD module is comprised of LaBr3:Ce scintillator, SiPM array and preamplifier. A large dynamic range of GRD is achieved by the high gain and low gain channels of the preamplifier. The energy response of GRD prototype was evaluated using radioactive sources in the range of 5.9-1332.5 keV. A energy resolution of 5.3% at 662 keV was determined from the Cs-137 pulse height spectra, which meets the GECAM requirement (< 8% at 662 keV). Energy to channel conversion was evaluated and a nonlinearity correction was performed to reduce the residuals (< 1.5%). Also, a Geant4-based simulated in-flight background and a measured GRD LaBr3:Ce intrinsic activity were used to evaluate the capability of in-flight calibration. These results demonstrate the design of GRD.