Design and Tests of a Detector for 222Rn in Soil-gas Measurements based on 222Rn Absorbing Scintillating Polymers

• Main Authors: Mitev, Krasimir K., Tsankov, Ludmil T., Mitev, Mityo G., Dutsov, Chavdar C., Georgiev, Strahil B., Kolev, Srebrin T., Markov, Nikolay M., Todorov, Todor Hr
• Format: Conference Proceeding
• Language: English
• Subjects: Detectors; Energy resolution; Optical detectors; Plastics; Scintillators; Soil measurements
• ISSN: 2577-0829
• DOI: 10.1109/NSSMIC.2017.8532818

This work presents the development and first tests of a detector for continuous ^{222}Rn in soil-gas measurements. It is based on scintillation spectrometry of ^{222}Rn absorbed in scintillating polymers-plastic scintillator foils or plastic scintillation microspheres. The detector consists of an optical chamber optically coupled to a hermetic volume which contains small sized spectrometric components: a photomultiplier tube, high voltage supply, multi-channel analyzer and an outside board with chip-controlled sensors for pressure, temperature,humidity and an accelerometer. The detector is compact,portable and is designed for ^{222}Rn in soil-gas in boreholes. Pilot laboratory studies of the performance of the detector are presented. They include: pulse-height spectrum characterization and energy resolution study with ^{239}Pu source; counting efficiency study and study of the pulse-height spectrum of a plastic scintillator with ^{222}Rn absorbed in it. The performance of the detector in the laboratory tests indicates that the approach to build a portable scintillation counter for ^{222}Rn in soil-gas measurements in boreholes is feasible.