• Energy Research
• Czech Academy of Sciences close

Aircrew exposure represents one of the recent subjects of occupational individual dosimetry. Since 1991 many new results have been found; there is however a need to gather further data on this exposure and its variation with geomagnetic position, solar activity and flight route parameters. Since 2001, many individual and six long-term monitoring programmes have been conducted onboard aircraft of Czech Airlines (CSA). In these programmes, a Si-diode spectrometer was fixed in an aircraft. Together with it, passive dosemeters thermoluminescent detector, track-etch based neutron dosemeter linear energy transfer and spectrometer) were exposed. More than 700 regular commercial flights were monitored in this manner. CSA supplied us also with full navigation data, which allowed us to calculate the exposure levels using EPCARD 3.2 and CARI6 codes. Direct experimental readings obtained with the detectors mentioned above were interpreted on the basis of calibrations in on-Earth reference fields and compared with calculated data. A satisfactory correlation between all sets of data was observed.

Owing to their professional activity, flight crews may receive a dose of some millisieverts within a year; airline passengers may also be concerned. The effective dose is to be estimated using various experimental and calculation tools. The European project DOSMAX (Dosimetry of Aircrew Exposure during Solar Maximum) was initiated in 2000 extending to 2004 to complete studies over the current solar cycle during the solar maximum phase. To compare various dosemeters in real conditions simultaneously in the same radiation field, an intercomparison was organised aboard a Paris-Tokyo round-trip flight. Both passive and active detectors were used. Good agreement was observed for instruments determining the different components of the radiation field; the mean ambient dose equivalent for the round trip was 129 +/- 10 microSv. The agreement of values obtained for the total dose obtained by measurements and by calculations is very satisfying.