The Italian National Survey of Aircrew Exposure: II. On-board Measurements and Results

Abstract

The Italian survey of aircrew exposure has been carried out with different advanced dosimetric systems, as described in part I of this paper. The key strategy of the survey was to obtain on-board comparison of measurements for both passive and real-time detectors flown together with passengers. The survey has been carried out in the period of solar minimum (1995-1997), in which the exposure to galactic cosmic rays reaches its maximum value. Even though carrying out the survey in the period of solar minimum was entirely coincidental, this circumstance has been used to good advantage to obtain a comprehensive set of data of the galactic cosmic radiation with little or no disturbance by the solar activity modulation. This comprehensive set of data covers flight routes between -20 degrees and 75 degrees geographic latitude at different civil aviation altitudes. The survey obtained with different advanced dosimetric systems has been supplemented by a large variety of data gathered with passive stacks on different short-range and long-range flights at supersonic and subsonic altitudes. Some of the most important conclusions which can be drawn from the survey are: (i) aircrew of civil aviation receive annual doses within the range of 1 mSv to 6 mSv; (ii) data from different periods of solar minimum agree well, since the discrepancies encountered seem mainly due to the different dosimetric systems used; (iii) repeated measurements on the same route are highly consistent.

The CERN-EU High-energy Reference Field (CERF) Facility for Dosimetry at Commercial Flight Altitudes and in Space

“…A diverse array of both passive and active instruments, to cover all radiation components of the field at aviation altitudes, was employed in the Italian national survey of aircrew exposure (10) . The detectors used were: the LINUS; the ANPA stack, a passive multidetector stack including bubble detectors (for low-energy neutrons), bismuth-fission track detectors (for high-energy neutrons), cellulose nitrate (LR-115 from Kodak) and polycarbonate films for high-Z particles, and various TLDs (including the hypersensitive Chinese lithium fluoride GR-200) for the low-LET component; the DIAS stack consisting of 20 sheets of CR-39 used to determine the fluence and type of charged particles as well as their LET; TEPC; PADC (CR-39); a highpressure ionisation chamber Reuter-Stokes type RSS-112 (based on a spherical stainless steel ionisation chamber filled with ultra-pure argon gas under high pressure).…”

“…A wide range of active instruments and passive devices has been employed in several measurement campaigns, mainly on-board commercial flights but also on some dedicated flights (see, for example, refs. (3,4,(7)(8)(9)(10)(11)(12)(13) ).…”