Environmental Monitoring and Assessment Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India.
Homi Bhabha National Institute, Trombay, Mumbai 400094, India.
Radiat Prot Dosimetry. 2024 Nov 18;200(19):1879-1891. doi: 10.1093/rpd/ncae196.
The energy response of gross gamma dose rate monitors needs to be flat in order to prevent overestimation of dose at low gamma energies. In this paper, a discriminator threshold modulation based electronic energy compensation algorithm has been proposed for SiPM-scintillator based gamma detectors. Theoretical simulation studies were carried out in order to optimize the parameters of the periodic ramp voltage used for modulation of the discriminator threshold of a SiPM-GGAG:Ce,B based gamma dose rate monitor. A customized threshold modulation circuit and signal processing electronics were developed for this gamma detector. For experimentally optimizing the parameters, the energy response studies of the detector, with and without the discriminator threshold modulation, were carried out. With the optimized parameters for a periodic ramp threshold, the count rates for 241Am (60 keV) and 60Co (1173 and 1332 keV) were observed to be within ±30% of the count rate obtained for 137Cs (662 keV). Using the electronic energy compensation techniques presented in this paper, a flat energy response of the SiPM-scintillator gamma detector for the energy range of 60 keV to 1.5 MeV could be achieved.
为了防止在低伽马能量下对剂量的高估，总伽马剂量率监测器的能量响应需要平坦。在本文中，提出了一种基于 SiPM-闪烁体的伽马探测器的基于甄别器阈值调制的电子能量补偿算法。为了优化用于调制 SiPM-GGAG:Ce,B 伽马剂量率监测器的甄别器阈值的周期性斜坡电压的参数，进行了理论模拟研究。为这个伽马探测器开发了定制的阈值调制电路和信号处理电子设备。为了在实验中优化参数，对探测器进行了能量响应研究，包括有无甄别器阈值调制两种情况。对于优化的周期性斜坡阈值参数，观察到 241Am（60keV）和 60Co（1173 和 1332keV）的计数率与 137Cs（662keV）的计数率相差在±30%以内。使用本文提出的电子能量补偿技术，可以实现 SiPM-闪烁体伽马探测器在 60keV 至 1.5MeV 的能量范围内的平坦能量响应。
