Radiation field of cosmic rays measured at aviation altitudes by CR-39 detectors

The radiation field of cosmic rays at aircraft altitudes is composed of primary galactic cosmic rays, solar energetic particles and their secondaries (charged particles and neutrons) produced in the Earth's atmosphere by nuclear interactions. Concerns regarding the effects of the cosmic radiation field at aircraft altitudes on aircrew and frequent travelers have resulted in a wide interest in detailed measurements. Nuclear track detectors have been used to investigate the radiation field for a complete solar cycle. LET (linear energy transfer) spectra (particle fluence, absorbed dose and dose equivalent) and charge spectra for HZE particles were obtained for both subsonic and supersonic flights. Comparisons between experimental results and the predictions of theoretical models have been made and show good agreement.