Improvement of the passive efficiency calibration of the segmented gamma scanner

摘要

The Segmented Gamma Scanner(SGS) technology is specially used for type identification and activity quantitative analysis of radioactive material in sealed containers, which mainly divided into the transmission measurement and the emission measurement. In actual measurement process, it cannot meet the need for rapid analysis because the efficiency calibration time takes up more than 60 % of the whole detect time in the data analysis. Whereas most previous research have focused on theory or specific applications, this research groups aim to different aspects of the SGS technique and direct it at an audience with interests in the need for rapid analysis. The Monte Carlo simulation calculation models were established by the passive efficiency calibration method, and then the detection efficiency database was carried out based on the experimental verification. Lots of work was used to analysis the influence of crosstalk between layers and interpolation step. Furthermore, the database was implanted into the control and analysis system to complete the measurement experiments. The results show the measuring time of single waste drums is about 30 min, and the average relative deviation is less than 10 %, so the problem that the time taken to calibrate the detection efficiency is too long has been solved effectively. The efficiency in the use of SGS technology has been increased.