Time Profile of Cosmic Radiation Exposure During the EXPOSE-E Mission: The R3DE Instrument

The aim of this paper is to present the time profile of cosmic radiation exposure obtained by the Radiation Risk Radiometer-Dosimeter during the EXPOSE-E mission in the European Technology Exposure Facility on the International Space Station's Columbus module. Another aim is to make the obtained results available to other EXPOSE-E teams for use in their data analysis. Radiation Risk Radiometer-Dosimeter is a low-mass and small-dimension automatic device that measures solar radiation in four channels and cosmic ionizing radiation as well. The main results of the present study include the following: (1) three different radiation sources were detected and quantified-galactic cosmic rays (GCR), energetic protons from the South Atlantic Anomaly (SAA) region of the inner radiation belt, and energetic electrons from the outer radiation belt (ORB); (2) the highest daily averaged absorbed dose rate of 426 mu Gy d(-1) came from SAA protons; (3) GCR delivered a much smaller daily absorbed dose rate of 91.1 mu Gy d(-1), and the ORB source delivered only 8.6 mu Gy d(-1). The analysis of the UV and temperature data is a subject of another article (Schuster et al., 2012).