Dosimetry of cosmic radiation in the upper atmosphere based on the measurements at the summit of Mt.Fuji

Cosmic radiation were measured in a facility of the Mt.Fuji Weather Station located at the summit of Mt. Fuji (3,776m in altitude), the highest mountain in Japan, during the summer of 2009, focusing on neutron doses. The 1cm ambient dose equivalent H*(10) of cosmic-ray neutrons at aviation altitude was estimated from the measurements at Mt.Fuji and compared to the data obtained in an civilian aircraft flying under nearly the same conditions of solar modulation and geomagnetic rigidity. According to the results, the simple empirical estimation based on the measurements at Mt. Fuji is expected so far to work effectively for dosimetry of cosmic-ray induced secondary partiles in the upper atmosphere.4th Asia-Pacific Smposium on Radiochemistry \u2709 (APSORC \u2709