半导体探测器信号成形中弹道亏损的影响因素探究

Exploration of Factors Influencing Ballistic Deficit in Semiconductor Detector Signal Shaping

摘要: 半导体探测器信号成形过程中，成形网络中电容的充放电会导致信号幅度出现弹道亏损，影响系统的能量分辨率和测量精度。根据探测器输出信号特性与信号成形电路特点，系统探究了弹道亏损的影响因素及内在机制。结果表明，弹道亏损不仅受信号成形电路参数(时间常数、级数)的制约，还与探测器外加电压、几何构型及材料特性密切相关。在实际应用中，可通过增加成形电路RC级的数目、提高探测器的外加电压和载流子迁移率来减小信号在成形网络中的弹道亏损。此外，探测器几何形状也是影响弹道亏损的关键因素，在同等条件下，选用厚度较小的探测器有助于降低信号的弹道亏损。本研究阐明了各因素间的耦合关系及其对弹道亏损的影响，为优化半导体探测器及其读出电子学设计、最小化弹道亏损效应并最终提升探测器系统性能提供了理论依据和实践指导。

Abstract: The charging and discharging of capacitors in the shaping network during the signal shaping process in semiconductor detectors would lead to a ballistic deficit in signal amplitude, which adversely affects the system’s energy resolution and measurement accuracy. This study systematically investigated the influencing factors and underlying mechanisms of ballistic deficit by analyzing the characteristics of the detector output signals and the features of the signal shaping circuits. The results demonstrate that the ballistic deficit is not only constrained by shaping circuit parameters (time constant, number of stages) but also related to the detector’s applied bias voltage, geometric configuration, and material properties. In practical applications, ballistic deficit within the shaping network can be reduced by increasing the number of RC shaping stages, the detector’s applied bias voltage, and the carrier mobility. Furthermore, the detector geometry is also a critical influencing factor. For a given condition, a detector with thin thicknesses is more helpful in reducing the ballistic deficit than a thick one. This research elucidates the coupling relationships among these factors and their impact on ballistic deficit, providing a theoretical foundation and practical guidance for optimizing semiconductor detector and readout electronics design, minimizing the ballistic deficit effect, and ultimately enhancing detector system performance.