A transimpedance amplifier (TIA) is an essential electronic circuit in prompt gamma detection. To improve the performance and reliability of the electronics, we designed a TIA using GaN high electron mobility transistor (HEMT) as it is more radiation-hardened when compared to its silicon counterpart and it has lower noise. Our circuit is designed using GaN HEMT from efficient power conversion (EPC) and has a 3-dB frequency of 21 MHz and 45 dB $\Omega $ of transimpedance gain. Its total output rms noise voltage is 3.1 mV. Its functionality is verified using a Lu-176 radiation source, and experimental result shows that the current generated from the H12700 position-sensitive photomultiplier tube (PSPMT) detector when the gamma radiation hits the scintillator crystal is successfully converted into voltage with the gain in agreement with our simulation result. Comparison of this GaN-based TIA with the reported silicon-based TIA shows superior performances for particle therapy imaging. The circuit is also tested under 100-MeV proton radiation with a fluence of $1.6\times 10^{11}$ cm $^{-2}$ and flux of $1.14\times 10^{8}$ cm $^{-2}\,\,\text{s}^{-1}$ , and negligible variations in the linearity and gain in the postradiation measurements are observed.

中文翻译：

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氮化镓技术在粒子治疗成像中的应用

跨阻放大器 (TIA) 是即时伽马检测中必不可少的电子电路。为了提高电子器件的性能和可靠性，我们设计了一种使用 GaN 高电子迁移率晶体管 (HEMT) 的 TIA，因为与硅对应物相比，它具有更强的抗辐射能力，并且噪声更低。我们的电路是使用来自高效功率转换 (EPC) 的 GaN HEMT 设计的，并且具有 21 MHz 和 45 dB 的 3-dB 频率 $\欧米茄 $ 的跨阻增益。其总输出均方根噪声电压为 3.1 mV。使用Lu-176辐射源对其功能进行了验证，实验结果表明，当伽马辐射撞击闪烁体晶体时，H12700位置敏感光电倍增管（PSPMT）探测器产生的电流成功转换为电压，增益一致与我们的模拟结果。这种基于 GaN 的 TIA 与报道的基于硅的 TIA 的比较显示了粒子治疗成像的优越性能。该电路还在 100-MeV 质子辐射下进行了测试，能量密度为 $1.6\乘以 10^{11}$ 厘米 $^{-2}$ 和流量 $1.14\乘以 10^{8}$ 厘米 $^{-2}\,\,\text{s}^{-1}$ ，并且观察到辐射后测量中线性度和增益的变化可以忽略不计。