Edge effects in a small pixel CdTe for X-ray imaging
Edge effects in a small pixel CdTe for X-ray imaging
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DOI：
10.1088/1748-0221/8/10/p10018
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发表时间：
2013-10-01
影响因子：
1.3
通讯作者：
Sawhney, K. J. S.
中科院分区：
文献类型：
--
作者：
Duarte, D. D.;Bell, S. J.;Sawhney, K. J. S.
在许多当代X射线成像应用中，需要能够在高于30 keV的能量下以高检测效率操作的大面积检测器。高Z化合物半导体（如CdTe）的特性使其非常适合这些应用。STFC Rutherford Appleton实验室开发了一种小像素CdTe探测器，像素为80 x 80，间距为250 m。从历史上看，这些探测器包括一个200微米宽的保护带周围的像素化阳极，以减少晶体边缘的缺陷的影响。最新版本的探测器ASIC能够进行四边对接，允许平铺N x N平板阵列。为了将模块之间的死空间限制在一个像素的宽度，已经开发了无边缘检测器几何结构，其中检测器的有效体积延伸到晶体的物理边缘。用密封辐射源测试了与HEXITEC ASIC凸块键合的无边缘CdTe探测器的光谱性能，并与在美国Diamond Light Source进行的单色X射线微束映射测量进行了比较。K.在59.54 keV的体积和边缘像素的平均能量分辨率分别为1.23 keV和1.58 keV。87%的边缘像素呈现出完全的光谱性能，这表明无边缘CdTe探测器是生产用于X射线成像的大型面板辐射探测器的有前途的技术。
Large area detectors capable of operating with high detection efficiency at energies above 30 keV are required in many contemporary X-ray imaging applications. The properties of high Z compound semiconductors, such as CdTe, make them ideally suitable to these applications. The STFC Rutherford Appleton Laboratory has developed a small pixel CdTe detector with 80 x 80 pixels on a 250 m m pitch. Historically, these detectors have included a 200 m m wide guard band around the pixelated anode to reduce the effect of defects in the crystal edge. The latest version of the detector ASIC is capable of four-side butting that allows the tiling of N x N flat panel arrays. To limit the dead space between modules to the width of one pixel, edgeless detector geometries have been developed where the active volume of the detector extends to the physical edge of the crystal. The spectroscopic performance of an edgeless CdTe detector bump bonded to the HEXITEC ASIC was tested with sealed radiation sources and compared with a monochromatic X-ray micro-beam mapping measurements made at the Diamond Light Source, U. K. The average energy resolution at 59.54 keV of bulk and edge pixels was 1.23 keV and 1.58 keV, respectively. 87% of the edge pixels present fully spectroscopic performance demonstrating that edgeless CdTe detectors are a promising technology for the production of large panel radiation detectors for X-ray imaging.