F. Wissmann

Validation of modelling the radiation exposure due to solar particle events at aircraft altitudes

Dose assessment procedures for cosmic radiation exposure of aircraft crew have been introduced in most European countries in accordance with the corresponding European directive and national regulations. However, the radiation exposure due to solar particle events is still a matter of scientific research. Here we describe the European research project CONRAD, WP6, Subgroup-B, about the current status of available solar storm measurements and existing models for dose estimation at flight altitudes during solar particle events leading to ground level enhancement (GLE). Three models for the numerical dose estimation during GLEs are discussed. Some of the models agree with limited experimental data reasonably well. Analysis of GLEs during geomagnetically disturbed conditions is still complex and time consuming. Currently available solar particle event models can disagree with each other by an order of magnitude. Further research and verification by on-board measurements is still needed.

Validation of Modelling the Radiation Exposure due to Solar Particle Events in Aircraft Altitudes. CONRAD Work package 6: Sub-Group (B) progress report

Dose assessment procedures for cosmic radiation exposure of aircraft crew have been introduced in most European countries in accordance with the corresponding European directive and national regulations. However, the radiation exposure due to solar particle events is still a matter of scientific research. Here we describe the European research project CONRAD, WP6, Subgroup-B, about the current status of available solar storm measurements and existing models for dose estimation at flight altitudes during solar particle events leading to ground level enhancement (GLE). Three models for the numerical dose estimation during GLEs are discussed. Some of the models agree with limited experimental data reasonably well. Analysis of GLEs during geomagnetically disturbed conditions is still complex and time consuming. Currently available solar particle event models can disagree with each other by an order of magnitude. Further research and verification by on-board measurements is still needed.

Dosimetry of secondary cosmic radiation up to an altitude of 30 km

Dosimetric measurements in the field of secondary cosmic radiation were extensively made during the last years. Since the majority of these measurements were performed on-board passenger aircraft at altitudes between 10 and 12 km, measurements at higher altitudes are desirable for the verification of the legal dose assessment procedures for aircrew. A simple solution is to use a high-altitude balloon that reaches altitudes as high as 30 km. In this work, it is shown that the dose rate profile up to 30 km can be measured with acceptable uncertainties using a Si-detector.

Cosmic radiation and aircrew exposure

The radiation field at flight altitudes is generated by the interaction of the primary cosmic radiation from space with atoms of the atmosphere. The cosmic particle flux is significantly higher on board aircraft than at the ground level and its intensity depends on latitude, altitude, solar activity and solar eruptions. Owing to the complexity of the field of secondary cosmic radiation—in fact this field consists of a variety of different particles including neutrons, protons, electrons, positrons, photons, positive and negative muons, etc., with kinetic energies exceeding the GeV range—there is no dosemeter system available so far that is able to cover the dose contributions of these particles separately.