Cross-talk elimination in determination of gross α and gross β activities using a low-background α/β gas-flow proportional counter / 中国辐射卫生

ABSTRACT

Objective To explore cross-talk elimination method in the determination of gross α and gross β activities using a low-background α/β gas-flow proportional counter. Methods A CLB-104 low-background α/β gas-flow proportional counter was used in this study. First, the α threshold was increased to eliminate the cross-talk counting caused by β particles in the α channel. Then, the α-β anticoincidence threshold was reduced to eliminate the cross-talk counting induced by low-energy α particles in the β channel, and β counts were corrected to eliminate the counts induced by internal convention electrons in the β channel. Finally, gross α and gross β activities of non-saline water samples with different activity levels were determined and compared with gross α and gross β activities of the same samples determined on a BH1227 low-background α/β solid scintillation counter, in order to verify effectiveness of the cross-talk elimination method. Results By eliminating the cross-talk counts of β particles in the α channel and the cross-talk counts of α particles in the β channel, and deducting the counts of internal convention electrons in the β channel, the gross α and gross β activities of the same samples determined by CLB-104 were consistent with the values determined by BH1227. Conclusion Cross-talk counts induced by low-energy α particles or β particles can be eliminated by threshold adjustment, and the counts caused by internal convention electrons in the β channel can be eliminated by correction.