SENSITIVITY ANALYSIS TO EVALUATE THE TRANSPORT PROPERTIES OF CdZnTe DETECTORS USING ALPHA PARTICLES AND LOW-ENERGY GAMMA-RAYS
SENSITIVITY ANALYSIS TO EVALUATE THE TRANSPORT PROPERTIES OF CdZnTe DETECTORS USING ALPHA PARTICLES AND LOW-ENERGY GAMMA-RAYS
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DOI：
10.5516/net.2011.43.6.567
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发表时间：
2011-12
影响因子：
2.7
通讯作者：
Kyung-O Kim;Woo Sang Ahn;Tae-Je Kwon;S. Kim;Jong Kyung Kim;J. Ha
中科院分区：
文献类型：
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作者：
Kyung-O Kim;Woo Sang Ahn;Tae-Je Kwon;S. Kim;Jong Kyung Kim;J. Ha
利用241Am源发射的两种不同的辐射(α粒子和伽马射线)，对用于评价镉锌Te探测器输运特性的方法进行了灵敏度分析。用Hecht方程拟合峰位置作为偏置电压的函数，得到了平面CZT探测器(5×5×2㎣)中电子-空穴对的迁移率-寿命产物。为了验证这些由α粒子和低能伽马射线产生的产物的准确性，通过结合特定位置的沉积能量和电荷收集效率，模拟了考虑探测器输运特性的能谱。研究发现，放大器组件的成形时间对(μτ)产物的测定有显著影响；α粒子法随着成形时间的增加而稳定，与使用伽马射线法时相比，对这种变化的敏感性较低。对于用α粒子方法估算的具有输运性质的能谱，峰位和尾部与测量结果略有不同，而从低能伽马射线得到的能谱与实验结果吻合较好。从这些结果证实，在寻求获得载流子的输运性质时，低能伽马射线比α粒子更有用，因为使用伽马射线的方法受CZT探测器表面条件的影响较小。此外，本研究所采用的蒙特卡罗模拟与Hecht模型相结合的分析系统，有望高度适用于CZT探测器特性的研究。
A sensitivity analysis of the methods used to evaluate the transport properties of a CdZnTe detector was performed using two different radiations (α particle and gamma-ray) emitted from an 241 Am source. The mobility-lifetime products of the electron-hole pair in a planar CZT detector (5×5×2 ㎣) were determined by fitting the peak position as a function of biased voltage data to the Hecht equation. To verify the accuracy of these products derived from α particles and low-energy gamma-rays, an energy spectrum considering the transport property of the CZT detector was simulated through a combination of the deposited energy and the charge collection efficiency at a specific position. It was found that the shaping time of the amplifier module significantly affects the determination of the (μτ) products; the α particle method was stabilized with an increase in the shaping time and was less sensitive to this change compared to when the gamma-ray method was used. In the case of the simulated energy spectrum with transport properties evaluated by the α particle method, the peak position and tail were slightly different from the measured result, whereas the energy spectrum derived from the low-energy gamma-ray was in good agreement with the experimental results. From these results, it was confirmed that low-energy gamma-rays are more useful when seeking to obtain the transport properties of carriers than α particles because the methods that use gamma-rays are less influenced by the surface condition of the CZT detector. Furthermore, the analysis system employed in this study, which was configured by a combination of Monte Carlo simulation and the Hecht model, is expected to be highly applicable to the study of the characteristics of CZT detectors.