Selective detection using pulse time interval analysis for correlated events in Rn-progeny with a microsecond lifetime

Sanada, Yukihisa   ; Kobayashi, Hirohide ; Furuta, Sadaaki; Nemoto, Kazuhiko*; Kawai, Keiichi*; Hashimoto, Tetsuo*

The purpose of this study is to develop new measurement methods of radon progenies that discharged alpha-ray focused on pulse time interval. It is calculated that a delayed coincidence method, time-interval-analysis (TIA), has been applied to decay events on the microsecond time-scale (164microsecond). The measurement system with silicon detectors was produced and examined a basic performance of the system by using Th electrodeposited sources. This system was designed that it have shorter dead times. The results were as follows. (1) The theory of measurement Po using TIA methods was established. (2) Development of the system that measured Po. (3) Suggested that methods to examine a basic performance by using Th electrodeposited sources. It is scheduled to examine the method of subtracting the progenies of the thorium series, and to reflect this system in an actual work of radiation control in the future.