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叙述了高阻硅和化合物半导体探测器的研制和它在核医学中的应用;着重分析了高阻硅探测器和GaAs探测器为满足在核医学中的应用以及探测器在制备中所必须解决的几个关键技术。对高阻硅探测器来说,必须提高对能量为28.5keV的~(125)IX射线的计数率(探测效率),为此采用了圆锥型台面结构,这一方面可以适当增加探测器样品的厚度,另一方面在相同工作电压下可提高探测器对电荷的收集电场。对GaAs探测器来说,必须提高探测器的电荷收集性能,为此采用了样品的减薄技术和制备欧姆接触的热处理技术。使GaAs探测器在加上适中的反向偏压后,可得到一全耗尽的探测器,并可得到较低的正向导通电压和一较薄的弱场区。解决了这几个技术关键后,探测器对28.5keV的~(125)IX射线的能谱响应和计数特性均有了明显的提高,在相同测试条件和本底计数的情况下,探测效率提高了三到五倍。
Describes the development of high-resistivity silicon and compound semiconductor detectors and its application in nuclear medicine. It focuses on analyzing the applications of high-resistance silicon detectors and GaAs detectors in nuclear medicine and the probe must be solved in the preparation Several key technologies. For high-resistivity silicon detectors, it is necessary to increase the counting rate (detection efficiency) of ~ (125) IX radiation with an energy of 28.5 keV. For this purpose, a conical mesa structure is used, which can appropriately increase the Thickness, on the other hand, increases the detector’s electric field for charge collection at the same operating voltage. For GaAs detectors, the detector’s charge-collection properties must be increased, using thinning techniques for the samples and heat-treatment techniques for making ohmic contacts. The GaAs detector plus a moderate reverse bias, you can get a fully depleted detector, and can get a lower forward voltage and a thinner weak field. Solve these technical key, the detector of 28.5keV ~ (125) IX spectrum of the spectral response and counting characteristics have been significantly improved in the same test conditions and the case of the background count, the detection efficiency Three to five times.