A Compton scattering background subtraction method of gamma energy spectrum based on Gaussian function convolution

Abstract

Due to the influence of the Compton effect and the relatively close gamma energy emitted during certain nuclide decays, gamma-ray spectrum analysis often faces challenges, such as a high count of Compton scattering continuum and overlapping peaks, which leading to some errors in energy spectrum analysis and low nuclide identification rates. This study proposes a spectrum analysis technique that uses Gaussian convolution to effectively eliminate background counts induced by Compton scattering. To minimize calculation errors in variance, the variance error is decreased from 2.98% to 0.84% through the utilization of a binary method for adjusting the transformation scale. Simulation results show that the average relative error of peak area calculations is less than 10.78%, and in the range of signal to noise ratio (SNR) greater than 22.5 dB, the differences between the standard peak center position and the peak center position measured by the Gaussian convolution method are less than 0.049%. The measured spectrum experiments were also carried out to confirm that the average relative error of peak area calculation is around 7.63%, and the relative error between the Gaussian convolution method and Gamma Vision peak-seeking result is around 0.18%. These results demonstrate that this method can effectively eliminate the Compton scattering background counts in the gamma spectrum, obtain the peak position and peak area of the full energy peak, and facilitate the accurate identification of the weak peak in the gamma spectrum.