Space radiation risk modelling
In the coming decades, space exploration will include the return of man on the Moon and the first manned Mars expedition. During these missions, astronauts will be continuously exposed to space radiation, constituted by ions ranging from Hydrogen up to Iron with a broad energy spectrum, making full shielding unfeasible. Additionally, they will occasionally face intense Solar Particle Events. To ensure astronaut safety, it is crucial to model the risk of such radiation exposure.
The Space Radiation Protection subgroup focuses on providing Relative Biological Effectiveness (RBE) estimates for various relevant biological endpoints, e.g. cancer induction. This is accomplished using the Local Effect Model (LEM), which calculates the RBE of charged particles based on the biological response of samples exposed to photon irradiation. While the LEM effectively retrieves single-particle, single-energy RBE data, this is insufficient for space radiation scenarios, where astronauts are subjected to complex radiation fields.
To address this, the Mixed Radiation Calculator (MiRaCal) toolkit was developed. MiRaCal exploits LEM results and integrates them using the formalism proposed by Zaider and Rossi, yielding RBE values for specific biological endpoints across entire mixed radiation fields.
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Publications on the topic
Hufnagl A, Scholz M, Friedrich T. Modeling Radiation-Induced Neoplastic Cell Transformation In Vitro and Tumor Induction In Vivo with the Local Effect Model. Radiation Research 195:427-440 (2021). doi:10.1667/rade-20-00160.1
Durante M, Cucinotta FA. Physical basis of radiation protection in space travel. Reviews of Modern Physics 83:1245-1281 (2011). doi:10.1103/revmodphys.83.1245