MATSIM Phase-A - Numerical Simulation of the Radiation Exposure of the MATROSHKA Phantom

MATROSHKA is an experiment designed to determine the radiation exposure of an astronaut during an extravehicular activity (EVA) at the International Space Station (ISS). For this purpose, several thousands passive and seven active radiation detectors measured the spatial dose distribution within an anthropomorphic phantom exposed outside the ISS (Figure Phantom).

The numerical modelling of the MATROSHKA phantom is done using the FLUKA Monte Carlo code to simulate the particles’ transport and interaction with matter. The code can simulate with high accuracy the interaction and propagation of different particles in a wide energy range such as photons and electrons from 1 keV to thousands of TeV, hadrons up to 20 TeV and all the corresponding antiparticles, neutrons down to thermal energies, and heavy ions. The code can handle very complex geometries.

A Computer Tomography (Figure CT_scan) of the MATROSHKA phantom can be converted into a 3-dimensional voxel phantom with the help of external software. The same geometry, material, density and distribution of the real phantom has to be used in the Monte Carlo model for the simulation of the radiation distribution inside the phantom (figure numerical_model).

The imparted energy and dose at the surface and in specified locations inside the phantom will be determined for special reference radiation conditions. The information gathered will be used in MATSIM-Phase B, for the validation of the numerical modelling of the dose distribution by measurements in photon and neutron fields.

Further investigations considering the complex radiation field onboard the ISS will allow the simulation of the dose distribution in the phantom under space radiation conditions. MATSIM will provide comprehensive risk assessment of radiation hazard to humans in space due to ionising and high energy particle radiation supporting the next project phase of the MATROSHKA experiment.

This project will therefore provide a detailed knowledge of the radiation environment at the ISS which is needed to assess radiation hazards to humans as well as to electronic devices, sensors and equipment.

Coordinator

ARC Austrian Research Centers GmbH, Radiation Safety and Applications Division
Department Radiation Safety Research - Dr. Peter Beck, Dr. Sofia Rollet

International Partners

• Vienna University of Technology, Atomic Institute of the Austrian Universities Radiology, Radiation Protection and Nuclear Measurement - Univ.- Prof. Norbert Vana, Univ.- Ass. Michael Hajek
• German Aerospace Center,  DLR, Institute of Aerospace Medicine, Department for Radiation Biology - Dr. Günther Reitz, Dr. Thomas Berger

Austrian Research Centers GmbH - ARC
Radiation Safety and Applications Division
Department Radiation Safety Research
A-2444 Seibersdorf

Dr. Peter Beck
E-mail: peter.beck@arcs.ac.at

Dr. Sofia Rollet
E-mail: sofia.rollet@arcs.ac.at