Measurements of heavy-ion anisotropy and dose rates in the Russian section of the International Space Station with the Sileye-3/Alteino detector

Abstract

In this work we present data on linear energy transfer (LET), dose and dose equivalent rates from different locations of the Russian part of the International Space Station (ISS) measured by the Sileye-3/Alteino detector. Data were taken as part of the ESA ALTCRISS project from late 2005 through 2007. The LET rate data shows a heavy-ion (LET>50 keV/μm) anisotropy. From the heavy-ion LET rate in the Zvezda service module we find ISS ŷ (Starboard) and ẑ (Nadir) to be about 10–15 times higher than in xˆ(Forward). The situation is similar for dose and dose equivalent rates, ranging from 25–40 μGy d⁻¹ in xˆ to about 75 μGy d⁻¹ in ẑ, whereas for the dose equivalent the rate peaks in ŷ with around 470 μSv d⁻¹. The heavy-ion anisotropy confirms what has been reported by the ALTEA collaboration. Measurements using two sets of passive detectors, DLR-TLDs and PADLES (TLD+CR-39), have also been performed in conjunction with Alteino measurements, both shielded and unshielded. The passive detectors register a dose rate about 3–5 times as high as Alteino, 260–280 μGy d⁻¹ for PADLES and 200–260 μGy d⁻¹ for DLR-TLDs. For the dose equivalent PADLES measurements ranges from 560–740 μSv d⁻¹.