Abstract
National Institute of Radiological Sciences (NIRS) has supported the assessment of cosmic radiation exposure of aircraft crew on request from domestic airline companies, according to the guideline settled on by the Radiation Council of the Japanese government. Radiation doses at aviation altitude are estimated by calculation using a particle transport model and are to be verified as to the accuracy of the estimated results by on-site measurements at high altitude. Thus, we have measured cosmic radiations at the summit of Mt. Fuji, the highest mountain in Japan (3,776m in altitude), and compared the results with calculations using a PHITS-based analytical model. Selected advanced neutron monitors coupled with exclusive data loggers were set in a building of the weather observatory for measurements from July 12 to August 25, 2008.
