Cosmic Radiation Protection Dosimetry Using an Electronic Personal Dosemeter (Siemens EPD) on Selected International Flights

The effectiveness of an Electronic Personal Dosemeter (Siemens EPD) for cosmic-radiation dosimetry at aviation altitudes was examined on eight international flights between March and September, 1998. The EPD values (Hepd) of the dose equivalent from penetrating radiation, Hp(10), were assumed to be almost the same as the electron absorbed doses during those flights. Based on the compositions of cosmic radiation in the atmosphere and the 1977 ICRP recommendation, an empirical equation to conservatively estimate the personal dose equivalent (Hp77) at a depth of 5 cm was derived as Hp77 = 3.1 x Hepd. The personal dose equivalent (Hp90) based on the 1990 ICRP recommendation was given by Hp90 = 4.6 x Hepd; the conservative feature of Hp90 was confirmed in a comparison with the calculated effective doses by means of the CARI-6 code. It is thus expected that the EPD will be effectively used for radiation protection dosimetry on selected international flights.