混合辐射场用混合CZT/PIPS探测器的物理约束协同优化与数据驱动的层分辨分类
Physics-Constrained Co-Optimization and Data-Driven Layer-Resolved Classification of a Hybrid CZT/PIPS Detector for Mixed Radiation Fields
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中文总结 AI 辅助
该研究针对混合辐射场需求，优化混合CZT/PIPS探测器结构，采用层分辨梯度提升分类器，通过Geant4模拟验证，最终设计满足U95模型的性能准则。
中文摘要 AI 辅助
紧凑型混合辐射仪器必须在保持低质量带电粒子入口的同时，提供足够的高Z深度以满足光子灵敏度需求。我们首先在40×20×10 mm³的设计预算内比较两种探测器头结构：S1将裸CdZnTe（CZT）与钝化注入平面硅（PIPS）分支并排布置，用于估计三种辐射率；S2在PIPS后方添加0.50 mm的CZT，用于估计X/γ、低β、高β和α四种辐射率。我们采用硬约束搜索方法，综合考虑光子衰减与沉积、Hecht电荷收集、带电粒子能量损失、立体角、分辨率预算、时序以及响应矩阵条件等因素。在初始设计包络内存在可行的筛选点，但经全新的输运/电子学评估后，在稳健H*(10)准则下仅得到25.04-25.07 cps/(μSv/h)的计数率，且所有保守电子学功耗均超过2.5% FWHM。因此，我们保留信息更丰富的S2观测结构，仅放宽10 mm的封装深度约束，将裸CZT划分为独立偏置的多个层，并添加低噪声求和通道用于光谱分析，同时采用层分辨梯度提升分类器进行混合场分析。扩展模拟采用Geant4 11.4.1生成的240万条历史数据，覆盖三个深度、五个输运种子和14种粒子/能量场景。最终的40×20×12.570 mm³探测器头包含7.870 mm厚的裸CZT，分为五层，每层偏置电压为180 V。在应用场景U95电子学配置下，其经活时间校正的662 keV灵敏度为32.804 cps/(μSv/h)，独立求和分辨率在第95百分位处为2.303% FWHM，且传播的β/α绝对效率下限分别为35.679%/39.832%。额外的端点输运覆盖20 keV-3 MeV光子、3-7 MeV α粒子以及155 keV-3.5 MeV β谱。该扩展设计因此满足U95模型下的原始探测器性能准则。
英文摘要
Compact mixed-radiation instruments must preserve a low-mass charged-particle entrance while providing enough high-Z depth for photon sensitivity. We first compare two detector heads within a 40 x 20 x 10 mm^3 design budget. S1 places bare CdZnTe (CZT) and passivated implanted planar silicon (PIPS) branches side by side and estimates three rates. S2 adds 0.50 mm of CZT behind PIPS to estimate X/gamma, low-beta, high-beta, and alpha rates. A hard-constraint search combines photon attenuation and deposition, Hecht charge collection, charged-particle energy loss, solid angle, resolution budgeting, timing, and response-matrix conditioning. Feasible screening points exist inside the initial envelope, but a fresh transport/electronics assessment gives only 25.04-25.07 cps/(uSv/h) under the robust H*(10) convention, and every conservative electronics draw exceeds 2.5% FWHM. We therefore retain the more informative S2 observation structure, relax only the 10 mm package-depth constraint, divide the bare CZT into independently biased layers, and add a low-noise sum channel for spectroscopy plus layer-resolved gradient-boosted classification for mixed-field analysis. The extension campaign contains 2.40 million Geant4 11.4.1 histories over three depths, five transport seeds, and 14 particle/energy cases. The final 40 x 20 x 12.570 mm^3 head uses 7.870 mm of bare CZT in five layers at 180 V per layer. Under the application-scenario U95 electronics profile, its live-time-corrected 662 keV sensitivity is 32.804 cps/(uSv/h), its independent-sum resolution is 2.303% FWHM at the 95th percentile, and the propagated beta/alpha absolute-efficiency lower bounds are 35.679%/39.832%. Additional endpoint transport covers 20 keV-3 MeV photons, 3-7 MeV alpha particles, and 155 keV-3.5 MeV beta spectra. The extended design therefore passes the original detector-performance criteria in the U95 model.
