Calculation of Most Efficient Volume of Detection by Using the Differential Volume Method in the EXVol Code

To calculate the full energy (FE) absorption peak efficiency for arbitrary volume sample, we developed and verified the EXVol (Efficiency calculator for eXtended Voluminous source) code which is based on effective solid angle method. Correction techniques for factors that interfere with γ-ray spectrum analysis are required for reliable nuclear characterization and radioactivity determination. And in the measurement of voluminous source of various forms and media, it is necessary to calibrate the effects of the self-attenuation and coincidence summing of the γ-ray depending on the volume and density of the sample. In this study, the performance of the EXVol code was extended to obtain the detection efficiency distribution at a specific position in the volume sample. And we obtained γ-ray detection efficiency and determined the most efficient volume contributing to detection efficiency of the large voluminous Si ingot source. As a result of the study, γ-ray detection efficiency and radiation distribution were obtained in the large volume and high density medium source.