Method to Enhance Detection Sensitivities of ¹³¹Xe^m and ¹³³Xe^m Measured by HPGe γ Spectrometer

Owing to their inert chemical properties, large fission yields, and abilities to easily vent into the atmosphere, detection of radioactive xenon isotopes (¹³¹Xe^m, ¹³³Xe^m, ¹³³Xe and ¹³⁵Xe) is one of the most effective technology of underground test monitoring. Due to the lower γ ray emission probability and energy overlapping of X ray, the detection sensitivities of ¹³¹Xe^m and ¹³³Xe^m are lower measured by using HPGe γ spectrometer. To enhance the detection sensitivities of ¹³¹Xe^m and ¹³³Xe^m, an X and γ ray interactive analysis method was developed. The distribution of the net peak counts in γ spectrum was deduced through Bayesian approach. The likelihood function of ¹³¹Xe^m and ¹³³Xe^m activities was established by using the distribution of net peak counts of X and γ ray. The activities of ¹³¹Xe^m and ¹³³Xe^m were estimated by maximum likelihood method. The detection sensitivities of ¹³¹Xe^m and ¹³³Xe^m are enhanced comparing with analyzing their γ ray.