A plastic scintillator gas detector designed for radioxenon isotopes measurement with a high electron detection efficiency

Four CTBT relevant radioxenon isotopes, namely (131)mXe, (133)mXe, Xe-133 and Xe-135, play a key role for underground nuclear test monitoring. In order to improve the detection sensitivity of radioxenon, a plastic scintillator detector, which was used as the detector as well as the gas sample cell, was developed. Then the performances of the plastic scintillator detector were tested. The hermetic seal was quite good with the leakage rate less than 1x10(-4)Pa.L/s. The energy resolution of 129.4 keV conversion electron associated with (131)mXe was determined to be 27%. A significantly high detection efficiency of-particle was achieved. The detection efficiencies of 346.4 keV -particle for Xe-133 and 129.4 keV conversion electron for (131)mXe are 0.966 +/- 0.029 and 0.988 +/- 0.005 respectively. The memory effect was found to be less than 3%. The plastic scintillator detector provides adequate foundation of beta-gamma(HPGe) coincidence measurement method research of high resolution and high sensitivity.

Automated summary

Four CTBT relevant radioxenon isotopes are crucial for underground nuclear test monitoring. A plastic scintillator detector was developed to enhance the detection sensitivity of radioxenon, with promising results that provide a solid foundation for high resolution and high sensitivity research.