基于虚拟点探测器的虚拟点源效率刻度技术

Virtual point source efficiency calibration technology based on virtual point detector

主要针对尺寸为75 mm×25 mm的241 Am标准体源HPGe探测器探测效率展开研究,通过LabSOCS软件模拟及蒙卡计算研究发现,使用同一种结构类型的探测器测量特定形状的体源,其虚拟点探测器位置与虚拟点源位置满足线性、二次函数、指数等关系。针对确定的探测器,通过点源在对称轴线上不同高度位置实验就可以标定出虚拟点探测器位置,再结合它们的线性函数进一步计算出虚拟点源位置,最后将点源放置于虚拟点位置刻度即可得到体源的探测效率。因此,该技术方法首次提出通过虚拟点探测器位置找到了虚拟点源的位置,是一种全新的刻度方法,已达到实际应用的程度,可以大面积推广应用该技术成果。

The detection efficiency ofφ75mm×25mm of 241Am standard samples were studied by using laboratory HPGe detection.When we used detectors with the same type of structure to measure a given volume source,the linearity function between the virtual point source and the virtual point detector was established by using LabSOCS software and Monte Carlo method.For a detector,the position of virtual point detector can be fixed by a point source placed at different height,and then,the position of virtual point source can be fixed by using their linearity function.The real calibration process will be carried out by placing a point source at its virtual position,namely,the volume source is replaced with the point source.Inconclusion,the position of virtual point source can be obtained through the virtual point detector.This is a completely new technology method,which will be widely applied in radioactive measurement.