Abstract Radon-222 is a naturally-occurring radioactive gas, and the measurement of this isotope and its progeny is of interest from the viewpoint of protection against internal exposure. The author has developed a new alpha/beta-imaging detector combined with a waveform digitizer capable of imaging alpha- and beta-particle locations simultaneously. A 0.9-mm-thick stilbene plate was optically coupled to a position-sensitive photomultiplier tube (PSPMT), and the analog signals from the PSPMT were transferred in parallel to the waveform digitizer. For 5.5-MeV alpha particles, the detection efficiency was 97.2% for 2pi steradians, and the energy resolution of the 5.5 MeV alpha peak was 21.6 ± 0.18% full width at half maximum (FWHM). The imaging detector was able to discriminate between alpha and beta particles via the pulse-shape-discrimination (PSD) technique, as well as being capable of alpha- and beta-particle imaging. The imaging detector was used for 222Rn-progeny measurements. When measuring the 222Rn progeny, both 214Bi and 214Po are imaged simultaneously, and a correlation is found between the positions of 214Bi and 214Po. The developed detector will be useful as a222Rn detector and in alpha-continuous-air monitoring for nuclear facilities.

中文翻译：

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使用薄二苯乙烯板开发用于氡 222 子代测量的 α 和 β 成像探测器

摘要 Radon-222 是一种天然存在的放射性气体，从防止内照射的角度来看，对这种同位素及其后代的测量很有意义。作者开发了一种新的 alpha/beta 成像检测器，结合了能够同时对 alpha 和 beta 粒子位置进行成像的波形数字化仪。0.9 毫米厚的二苯乙烯板与位置敏感光电倍增管 (PSPMT) 光耦合，来自 PSPMT 的模拟信号并行传输到波形数字化仪。对于 5.5-MeV α 粒子，2pi 球面度的检测效率为 97.2%，5.5 MeV α 峰的能量分辨率为 21.6 ± 0.18% 半峰全宽 (FWHM)。成像探测器能够通过脉冲形状辨别 (PSD) 技术区分 α 和 β 粒子，并且能够对 α 和 β 粒子成像。成像检测器用于 222Rn 后代测量。在测量 222Rn 后代时，214Bi 和 214Po 同时成像，发现 214Bi 和 214Po 的位置之间存在相关性。开发的探测器将用作 222Rn 探测器和核设施的 alpha 连续空气监测。