口袋式伽马能谱仪研制

Development of pocket energy spectrometer

摘要:

便携式伽马能谱仪在野外探矿、环境辐射监测和科学实验等领域被广泛应用. 为了进一步缩小便携式能谱仪的体积，提高其能谱性能，从而扩展其应用领域，本文基于最新的闪烁晶体材料、半导体光电转换器件和高性能微处理器，开展了新一代便携式伽马能谱仪研究. 在探测器设计方面，采用GAGG:Ce晶体耦合SiPM阵列成功设计并制作了高效率、高能量分辨率的紧凑型能谱探头；在数据采集电路方面，采用高性能ARM处理器及其自带ADC外设替代FPGA+ADC的传统电路架构，并设计专用的信号处理ARM程序，实现了在线能谱测量，并极大的减小了电路尺寸和系统功耗. 综上所述，本文基于GAGG:Ce晶体耦合SiPM并搭配ARM处理器，成功研制了一款低成本、小体积、低功耗、高性能的口袋式能谱测量仪. 整个能谱仪的体积仅为80 mm×40 mm×40 mm，重量为200 g；经过实验测试，能谱仪的工作功率为481 mW，能自带电池工作26小时；能谱响应线性拟合优度为0.996，能量分辨率为5.2 %（@662 keV).

关键词:伽马能谱仪; GAGG; SiPM; ARM

Abstract:

Portable gamma spectrometer is widely used in many fields, such as field prospecting, environmental radiation monitoring and scientific experiments. In order to further reduce the volume of portable energy spectrometer and improve its energy spectrum performance, so as to extend its application field. Based on the latest scintillation crystal materials, semiconductor photoelectric converters and high performance microprocessors, we have developed a new generation of portable gamma spectrometer. In terms of detector design, GAGG: Ce crystal coupled SIPM array is used to successfully design and manufacture a compact energy spectrum probe with high efficiency and high energy resolution; in terms of data acquisition circuit, high performance ARM processor and its own ADC peripheral are used to replace the traditional circuit architecture of FPGA + ADC, and a special signal processing ARM program is designed to realize online energy spectrum measurement, which greatly reduce the circuit Size and system power consumption. To sum up, based on GAGG: Ce crystal coupled SIPM and ARM processor, a pocket type energy spectrometer with low cost, small volume, low power consumption and high performance has been successfully developed. The volume of the whole spectrometer is only 80 mm × 40 mm × 40 mm, and the weight is 200 g. The tested power of the spectrometer is 481mW, and it can work for 26 hours with its own power supply. The linear goodness of fit of the spectral response is 0.996, and the energy resolution is 5.2% (@ 662 keV).

Key words:Gamma spectrometer; GAGG; SiPM; ARM