@misc{oai:repo.qst.go.jp:00070711,
 author = {Omori, Yasutaka and Miroslaw, JANIK and Sorimachi, Atsuyuki and Ishikawa, Tetsuo and Tokonami, Shinji and 大森 康孝 and ミロソラフ ヤニック and 反町 篤行 and 石川 徹夫 and 床次 眞司},
 month = {Mar},
 note = {Among the sources, naturally-originated radon isotopes (radon and thoron) are considered to be a significant factor to human exposure. For investigating their contributions, there are two considerations in the measurement of the concentrations: (1) the discrimination of radon and thoron and (2) the long-term measurement in widespread area.
Based on the above concepts, the National Institute of Radiological Sciences developed a passive-type radon-thoron discriminative detector, commercially called Raduet, and has provided worldwide in many indoor survey. The detector consists of diffusion chambers with different ventilation rate where CR-39 chips are deployed. This characteristic allows to determine radon and thoron concentration discriminatively. On the other hand, inside air is not easily replaced with outside fresh air in the chamber with low ventilation rate compared to the other one, so that one needs a special care against the possibility that the remained air after the exposure disturbs the estimation of radon and thoron concentration. This effect should also be considered in a calibration experiment to assure the performance of the radon-thoron discriminative detector as well as in a survey in high-background area.
In this presentation, ventilation rate of the diffusion chambers is derived and, based on the result, temporal variations of radon and thoron concentrations in each chamber are simulated. In addition, the contribution of the remained air after the exposure to the estimation of radon and thoron concentration is discussed., International Symposium on Natural Radiation Exposures and Low Dose Radiation Epidemiological Studies},
 title = {Ventilation property of a passive-type radon-thoron discriminative detector},
 year = {2012}
}