In-flight validation and routine measurements

Different methods of aircrew dose assessment are under discussion and evaluation by several international research groups. The TEPC (tissue-equivalent proportional counter) has been used very successfully to describe the radiation field during in-flight measurements. Cosmic ray transport calculations of effective dose have been compared with TEPC measurements, with good results. Several active conventional photon and neutron detectors, as well as a passive dosemeter, have been prepared and characterised for in-flight radiation measurements. A novel method, combining measurements with a conventional radiation detector and results of cosmic ray transport calculations is at present under evaluation in the European research project ACREM (Air Crew Radiation Monitor). Superimposed on the regular and more-or-less predictable eleven year cosmic ray intensity variation, events on the sun will occasionally result in high energy particle fluxes that will impact on the tellurian atmosphere and result in unforeseen high additional radiation exposures. Appropriate methods to determine the resulting radiation dose rates will be described.