Digital logarithmic airborne gamma ray spectrometer

作者:Zeng Guo-Qiang*; Zhang Qing-Xian; Li Chen; Tan Cheng-Jun; Ge Liang-Quan; Gu Yi; Cheng Feng
来源:Chinese Physics C, 2014, 38(7): 076001.
DOI:10.1088/1674-1137/38/7/076001

摘要

A new digital logarithmic airborne gamma ray spectrometer is designed in this study. The spectrometer adopts a high-speed and high-accuracy logarithmic amplifier (LOG114) to amplify the pulse signal logarithmically and to improve the utilization of the ADC dynamic range because the low-energy pulse signal has a larger gain than the high-energy pulse signal. After energy calibration, the spectrometer can clearly distinguish photopeaks at 239, 352, 583 and 609 keV in the low-energy spectral sections. The photopeak energy resolution of Cs-137 improves to 6.75% from the original 7.8%. Furthermore, the energy resolution of three photopeaks, namely, K, U, and Th, is maintained, and the overall stability of the energy spectrum is increased through potassium peak spectrum stabilization. Thus, it is possible to effectively measure energy from 20 keV to 10 MeV.