2021/12/13 by K. Okamoto, Y. Nakano, Okamoto, K. +11
Health Professions · Medicine · Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #Instrumentation and Detectors (physics.ins-det) #Medical Imaging Techniques and Applications #Nuclear Experiment (nucl-ex) #Radiation Detection and Scintillator Technologies #Radioactivity and Radon Measurements
paper · pdf · doi:10.48550/arxiv.2112.06614
openalex publication_date 2021/12/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Radioactive noble gas radon (\mathrm222Rn) is one of the major background sources below the MeV region in rare event search experiments. To precisely measure radon concentration in purified gases, a radon detector with an electrostatic collection method is widely used. In this paper, we discussed the improvements of a radon detector by installing a new PIN-photodiode (28×28 mm) whose surface area is 2.5 times larger than that used previously (18×18 mm). We evaluated the detector's performance by serially connecting two radon detectors equipped with two types of PIN-photodiodes. As a result of the calibrations, we found an improvement of (3.8±2.4)% in the detection efficiencies below 1.0 \mathrmg/m3, while a 10-20% improvement occurred above this level. The intrinsic background of the detector equipped with the large PIN-photodiode was measured as 0.24+0.09-0.05 \mathrmmBq/m3. This background level is consistent with the radon detector with the small PIN-photodiode, although we installed the large one. This improvement is useful for applications in radon emanation measurements from a material, which also emits water from its surface.