基于递推关系式的γ能谱全能峰基底扣减方法

Continuum Subtraction Method under Full-energy Peak in γ Spectrum Based on Recursion Formula

为准确估计γ能谱全能峰下侧的基底计数,提出了基于递推关系式的基底扣减方法。首先利用蒙特卡罗模拟给出了单峰和重峰情况下基底的理论形态,然后对模拟中基底的形成过程进行数学抽象,得到相邻两道基底间的递推关系式。利用此关系式,结合边界条件,求解出最终的基底计算公式。实际应用显示,使用该公式于模拟的γ能谱,计算基底与理论基底吻合较好;使用该公式于实测γ能谱,扣减基底后的全能峰的拟合优度优于传统的线性基底扣减法。新的基底扣减方法在原理上更符合基底的形成机制,实际效果也较传统方法好。

In order to accurately estimate the continuum counts under full-energy peaks in γ spectrum,a continuum subtraction method based on recursion formula was proposed.First,the theoretical continuum shape was provided by Monte-Carlo simulation,then the forming process was mathematically abstracted,and a recursion formula of the continuum counts in adjacent channels was constructed consequently.With this formula and additional boundary conditions,the final continuum subtraction formula was achieved.Application experiments show that the continuum calculated by the new method fits the theoretical shape well for the simulated spectrum,and after subtracting continuum by the new method the full-energy peaks display a better figure of merit than using the traditional linear method for the measured spectrum.The new method agrees with the continuum forming mechanism better in principle,and also performs better.