Detection efficiency of a high-pressure gas scintillation proportional chamber.
Detection efficiency of a high-pressure gas scintillation proportional chamber.
复制标题
高压气体闪烁比例室的检测效率。
DOI：
10.1118/1.596098
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
R. Lanza
中科院分区：
文献类型：
--
作者：
F. Fahey;R. Zimmerman;P. Judy;R. Lanza
通过测量和蒙特卡罗模拟，研究了用于医学成像的高压气体闪烁比例室（GSPC）在30- 150kev能量范围内的检测效率。测量是在含有4 atm纯氙的GSPC上进行的，该纯氙是从由7个紫外敏感光电倍增管组成的六边形阵列中通过1.27厘米厚的熔融硅窗分离出来的。实验测量了光峰效率、荧光逃逸效率和能量收集效率。在不同的光子能量和不同的时间分辨率值下也得到了结果。测量结果与蒙特卡罗模拟结果进行了比较，蒙特卡罗模拟是专门为研究低能光子（低于150 keV）与充气探测器的成像而设计的。模拟计算了光峰效率、荧光逸出效率、光峰-荧光逸出峰比、量子相互作用效率、能量收集效率和局部能量收集效率。GSPC相对于3-in的光峰效率。测得（7.62 cm）厚的碘化钠晶体在60 keV下为0.284 +/- 0.001，在140 keV下为0.057 +/- 0.001。在入射到探测器上的60 kev光子中，70% +/- 4%在探测器中相互作用，28% +/- 1%在光峰中。在60 keV时，最大能量收集效率为65%，其中46%沉积在初始光子相互作用的0.2 cm内。从这项研究中获得的信息正在用于设计一种优化的探测器，用于专门的核医学研究。
The detection efficiency of a high-pressure, gas scintillation proportional chamber (GSPC), designed for medical imaging in the 30-150 keV energy range, has been investigated through measurement and Monte Carlo simulation. Measurements were conducted on a GSPC containing 4 atm of pure xenon separated from a hexagonal array of seven ultraviolet-sensitive photomultiplier tubes by 1.27-cm-thick fused-silica windows. Experimental measurements of the photopeak efficiency, fluorescence escape efficiency, and the energy collection efficiency were obtained. Results were also obtained for different photon energies and different values of temporal resolution. The measurements were compared with the results obtained from a Monte Carlo simulation designed specifically for investigating the imaging of low-energy photons (below 150 keV) with a gas-filled detector. The simulation was used to estimate photopeak efficiency, fluorescence escape efficiency, photopeak-to-fluorescence escape peak ratio, quantum interaction efficiency, energy collection efficiency, and local energy collection efficiency. The photopeak efficiency of the GSPC relative to that of a 3-in. (7.62-cm)-thick sodium iodide crystal was measured to be 0.284 +/- 0.001 at 60 keV and 0.057 +/- 0.001 at 140 keV. Of the 60-keV photons incident upon the detector, 70% +/- 4% interacted in the detector, with 28% +/- 1% being in the photopeak, as estimated both by experimentation and through the simulation. The maximum energy collection efficiency was found to be 65% at 60 keV, with 46% being deposited within 0.2 cm of the initial photon interaction. The information gained from this study is being used to design an optimized detector for use in specialized nuclear medicine studies.