@article{oai:repo.qst.go.jp:00043330,
 author = {Ichitsubo, Hirokazu and Tokonami, Shinji and Miyamoto, Katsuhiro and Yamada, Yuji and 一坪 宏和 and 床次 眞司 and 宮本 勝宏 and 山田 裕司},
 journal = {High Levels of Natural Radiation and Radon Areas : Radiation Dose and Health Effects : Proceedings of the 5th International Conference on High Levels of Natural Radiation and Radon Areas, held in Munich,Germany on September 4 to 7, 2000 vol.II :Poster Presentation(BfS Schriften 24-2002)},
 month = {Jul},
 note = {Radiation detectors (of the circular type) are utilized for the detection of radioactive particles deposited, e.g., (i) on each cascade impactor stage, in the measurement of radioactive aerosol particle size distribution and (ii) on air filters for the measurement of concentrations of radioactive aerosols (e.g. radon progeny) in the environment. The counting efficiency of the detector is related to both the geometric size of the detector, and the deposited area of radioactive aerosol particles. Although the detector size, for example, represents a constant factor unless the detector is exchanged, the area of deposition on the impactor stage or a filter is not of constant dimensions. When a cascade type impactor is used, the area of deposited aerosol particles is different for each impactor stage. In this report, we discuss the effects of both the geometric size of the detector, and the size of the area of deposition, on geometric counting efficiency. We also discuss the effective detection area of a radiation detector. The geometric counting efficiency decreases distinctly with increasing distance between the detector and the sample containing the deposited particles, when the area of deposited aerosol particles is equal in size to the detector. This result means that the effective diameter of the detector can be estimated by measuring the distinctive counting efficiency curve. We found that the actual working detection area (effective detection area) of radiation detectors available on the market could be calibrated by measuring the curve. If accurate measurement of size distribution is required using a particular kind of cascade impactor, detected radiation levels at each impactor stage should be corrected, including the parameters relating to the influence of the effective detection area of the detector, and for the actual area of deposition for the sample on each impactor stage.},
 pages = {39--42},
 title = {EVALUATION OF THE EFFECTIVE DETECTION AREA OF RADIATION DETECTORS},
 year = {2002}
}