Keywords:Fukushima Daiichi Nuclear Power Station accident, airborne radiation measurement , unmanned helicopter, radiocesium, vertical distribution, peak to compton ratio
After the Fukushima Daiichi Nuclear Power Station accident, most of radiocesium was exited in surface soil. However, variation of radiocesium depth was reported because of soil disturbance with wild animals and soil erosion with heavy rain. It is important information about the vertical distribution of radiocesium in soil for effective decontamination works in high-dose areas. In general cases, it is quite troublesome to investigate the vertical distribuiton of radiocesium for collecting and mesuring of soils. In this study, we devloped an anlytical method using an unmanned helicopter for estimating the vertical distribuiton of radiocesium in soil rapidly and easily.