BGO量能器大动态范围读出的线性标定系统的设计和实现

The Design and Realization of Linear Calibration System of a Large Dynamic Range Readout Unit for a BGO Calorimeter

暗物质空间探测器是中国科学院紫金山天文台空间实验室提出的,其目的是为了探测暗物质粒子湮灭可能产生的高能电子和伽玛粒子.BGO量能器是暗物质粒子探测卫星主要载荷之一,高能粒子的能量主要沉积在BGO量能器中.为了使探测器覆盖5 GeV^10T'eV的探测范围,要求每个BGO探测单元具有约1.5×10~5的动态范围.为了对这一大动态范围的探测单元进行测试,提出一种比较简易的线性测试方法,并在实验室构建一个相应的测试系统,对BGO量能器探测单元读出系统的线性进行测试.测试结果表明BGO量能器探测单元读出的非线性度好于2.7%.

The DArk Matter Particle Explorer （DAMPE） is proposed by Purple Moun- tain Observatory, Chinese Academy of Sciences. This project expects to find the evidence of the existence of dark matter particle in the universe via the detection of high-energy elec- tron and gamma-ray. A major component of the payload is a BGO （Bismuth Germanate Oxide） calorimeter, which is used to detect the particles in the energy range from 5 GeV to 10 TeV. According to a physical simulation, the dynamic range of each BGO detection unit is about 1.5x105. In order to test the linearity of BGO detection readout unit, we implement a simple linearity calibration system covering such a large dynamic range. The experimental result shows that the nonlinearity of the entire dynamic range is less than 2.7%.