A prototype high-purity germanium detector system with fast photon-counting circuitry for medical imaging.
A prototype high-purity germanium detector system with fast photon-counting circuitry for medical imaging.
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DOI：
10.1118/1.596606
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发表时间：
1991-09
期刊：
影响因子：
3.8
通讯作者：
Bruce H. Hasegawa;Benno Stebler;Brian K. Rutt;Alberto Martinez;Eric L. Gingold;Craig S. Barker;Kenneth G. Faulkner;Christopher E. Cann;D. P. Boyd
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文献类型：
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作者：
Bruce H. Hasegawa;Benno Stebler;Brian K. Rutt;Alberto Martinez;Eric L. Gingold;Craig S. Barker;Kenneth G. Faulkner;Christopher E. Cann;D. P. Boyd
一种用于x射线医学成像的数据采集系统采用分段的高纯锗(HPGe)探测器阵列，具有2 mm宽和6 mm厚的元件。探测器包含在液氮低温恒温器内，旨在将热量损失降至最低。选择前置放大电路的50 ns脉冲成形时间作为与探测器的50 ns电荷收集时间兼容的最短时间常数。这为检测系统提供了最快的计数速率能力和对微音学的免疫力，具有中等的能量分辨率性能。对前置放大器电子学的理论分析表明，其噪声性能主要受其输入电容的限制，并且与高达约100nA的探测器泄漏电流无关。该系统实验证明，对于来自241Am的60keV伽马射线光子，计数率超过每元素每秒100万次，能量分辨率为7keV结果表明，采用适合于双能量成像的HPGe探测器系统以及同时提供X射线传输和放射性核素发射成像的系统的数据采集系统的性能。
A data-acquisition system designed for x-ray medical imaging utilizes a segmented high-purity germanium (HPGe) detector array with 2-mm wide and 6-mm thick elements. The detectors are contained within a liquid-nitrogen cryostat designed to minimize heat losses. The 50-ns pulse-shaping time of the preamplifier electronics is selected as the shortest time constant compatible with the 50-ns charge collection time of the detector. This provides the detection system with the fastest count-rate capabilities and immunity from microphonics, with moderate energy resolution performance. A theoretical analysis of the preamplifier electronics shows that its noise performance is limited primarily by its input capacitance, and is independent of detector leakage current up to approximately 100 nA. The system experimentally demonstrates count rates exceeding 1 million counts per second per element with an energy resolution of 7 keV for the 60-keV gamma ray photon from 241Am. The results demonstrate the performance of a data acquisition system utilizing HPGe detector systems which would be suitable for dual-energy imaging as well as systems offering simultaneous x-ray transmission and radionuclide emission imaging.