Review and Cross-comparison of Matroshka Phantom Measurements in Different Compartments of the International Space Station

Full text: Astronauts working and living in space are exposed to considerably higher doses and different qualities of ionizing radiation than people on ground. Matroshka, a European Space Agency experiment under coordination of the German Aerospace Centre, is the most comprehensive effort so far in radiation protection dosimetry in space using an anthropomorphic upper torso phantom known from radiotherapy treatment planning to map the dose distribution throughout a simulated human body on board the International Space Station (ISS). Absorbed dose and dose equivalent measured by nuclear track detectors and miniature thermoluminescence dosimeters embedded in a regular grid and at the site of vital organs are combined with detailed numerical models to allow for estimation of effective dose. Monte Carlo simulations using the transport codes FLUKA and GEANT4 that provide calculations of particle fluence and dose for various radiation environment conditions further support the experiment and improve cancer risk projections for future long-term space exploration beyond the Earths magnetosphere. The paper presents a review and cross-comparison of data acquired during four missions between January 2004 and March 2011, in which the phantom has been installed in different compartments of the Russian and Japanese segments of the ISS: outside and inside Zvezda, inside Pirs and inside Kibo. (author)