Relative nuclear abundances, LET and dose rates atvarious locations and configurations in ISS from the ALTCRISS experiment
Fuglesang, Christer ; Larsson, Oscar ; Lund-Jensen, Bengt ; et al. ; - ASI Sponsor
Dec - 2013

Event Title : 64th International Astronautical Congress; Beijing, China, 23-27 September 2013
Published in: 64th International Astronautical Congress: Radiation Fields, Effects and Risks in Human Space Missions, 2013
Publisher: IAC, 13-A1.4.5
type: Conference Proceedings

Over the years many devices, using different technologies and various locations, have been used - and are still in use - on the International Space Station, ISS, to measure and map the radiation and cosmic particle flux which astronauts as well as sensitive electronics are exposed to. This presentation presents recent analyses and results from the SilEye-3/Alteino detector during the ESA-sponsored project ALTCRISS. Comparisons are made with data from other experiments, such as ALTEA and PADLES. Alteino is a Si-strip detector, developed from the two SilEye detectors that were operated on Mir, in particular for studies of the Light Flash phenomena. Alteino was used at several locations, and orientations, in the Russian segment of ISS from late 2005 through 2007. Many of the data sets were obtained with a shielding of 5 g/cm2 polyethylene in front of the detector. Data on nuclei from C to Fe in the energy range above ≃ 60 MeV/n show an increase in relative abundance for odd Z inside ISS compared to the outside, due to fragmentation in the hull. Fluxes and relative abundances vary with location and shielding, where the material of the station itself plays a major role. The difference in flux can be as much as 50%. LET spectra - which are not restricted to single particle events - show similar tendencies, though when converted to equivalent dose rates the effect of the polyethylene is somewhat pronounced. Comparison with ALTEA data shows slightly higher dose rates for Alteino in the Russian segment, which can be expected due to that ALTEA operated in the US lab Destiny with more station material around it. As expected, the response of CR39 in terms of equivalent dose rate is higher than Alteino, due to the smaller acceptance energy range of the latter.

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