The radiation environment observed by Liulin-Photo and R3D-B3 spectrum-dosimeters inside and outside Foton-M3 spacecraft

Abstract

In this study we present the results obtained by the couple of active spectrum-dosimeters Liulin-Photo and R3D-B3 on board the Foton-M3 satellite, which flew in Low Earth Orbit from 14 to 26 September 2007. During the Foton-M3 flight the two dosimeters measured in real-time the deposited energy spectrum by the incident ionizing particles, the particle flux and the absorbed dose behind different shielding. By applying recently developed methods to the dosimeter measurements, an assessment of the ambient equivalent dose H*(10) is also performed, distinguishing the dose contributions of low- and high-LET radiation components and evaluating H*(10) in different sectors along the satellite orbit. The experimental data are compared with the results of simulations performed by using the GEANT4 MC code and the SPENVIS and OMERE space environment tools for the free-space particle spectra modelling. The Foton-M3 mission took place during a continuous period of very low solar activity in the minimum phase of the 23rd solar cycle. The results presented in this study contribute to the assessment of the properties of the Low Earth Orbit radiation environment during a well-defined and stable phase of the solar activity and they will be also useful for all those experiments on board Foton-M3 which were sensible to the effects of the ionizing space radiation.