Status of the DESIRE project: Geant4 physics validation studies and first results from Columbus/ISS radiation Simulations

Abstract

The Dose Estimation by Simulation of the ISS Radiation Environment (DESIRE) project aims to accurately calculate radiation fluxes and doses to astronauts inside the European Columbus module of the International Space Station using Geant4. Since Geant4 has not been previously used for this type of application it needs to be validated. This will be followed by a detailed evaluation of the incident radiation fields on ISS and culminate with the geometry modeling and full-scale flux and dose simulations for Columbus. Geant4 validation studies and comparisons to other tools are presented. These concern the angle and energy distributions of particles leaving irradiated targets and of energy depositions in the targets. Comparisons are made between simulations using different Geant4 physics models, experimental data, and other particle transport programs. Geant4 using the "Binary Cascade" model for inelastic nucleon reactions performs very well in these comparisons, but some issues with other models remain to be resolved if they are to be used for space radiation shielding applications. Results of Geant4 simulations of the transport of some relevant radiation field components through the hull of a simplified model of Columbus are also presented.

Geant4 Applications in Space

“…Geant4 [1,2] is widely and commonly used for various current and future science missions including XMM-Newton [3], GLAST [4], LISA and LISA Pathfinder [5], RHESSI [6], ACE [7], JWST [8], INTEGRAL [9], Bepi Colombo [10], Messenger [11], Herschel [12], Cassini and Huygens [13], Astro-E2 [14], ConeXpress [15], SELENE [16], SWIFT [17] and modules of ISS (International Space Station) including Columbus [18], AMS [19] and MAXI [20]. In the following sections, I will overview how Geant4 is used for some of these missions.…”

“…Full geometry model of ISS (International Space Station) and particularly detailed apparatus structure of European Columbus module are built to accurately calculate radiation fluxes and doses to astronauts inside the Columbus module [18]. Incident radiation includes trapped protons, galactic cosmic rays, solar particle events and Earth albedo neutrons.…”

Using the human eye to image space radiation or the history and status of the light flash phenomena

“…How can we improve space-craft design to keep doses as low as possible? The DESIRE project [29,30] attempts to help find the answers to some of these general questions about radiation doses in space by simulations with Geant4 [31]. In particular, a very detailed computer model of ESA's ISS Columbus module has been developed and dose rates have been calculated under various conditions.…”

Dose calculations at high altitudes and in deep space with GEANT4 using BIC and JQMD models for nucleus–nucleus reactions

“…The code chosen and supported by ESA for such studies is the Monte Carlo software package GEANT4 [4], which has been used in Europe and the US for studies of space radiation effects. It has, e.g., recently been used for studies of the Columbus/ISS radiation environment [5]- [10] within the ESA-sponsored project 'Dose Estimation by Simulation of the ISS Radiation Environment' (DESIRE) [11]. A longterm goal of the DESIRE activity has been to develop a European software package that can be used to predict the radiation risks for human space flights, both in LEO as well as to the Moon and Mars.…”