Speaker
Mr
Benjamin RUARD
(Artenum)
Description
The increasing complexity of future commercial missions and space environments of new scientific missions impact more aggressively and deeply the design of next generation space systems, payloads as well as the platforms. The use of COTS components and the mass optimization require a finer modeling of the impact of space environment on spacecraft, especially regarding radiation and internal charging effects. We are reaching now the limits of models like the sector shielding (ray-tracing) analysis and 3D realistic descriptions are needed for good results. New ESA missions will across complex space environments where the limit between canonical physical domains is not strict anymore and a multi-physics approach is required.
For radiation and internal charging effects, thanks to a long-term R&D effort sustained at ESA/TEC-EPS and inside the community, a set of Monte-Carlo based simulation models are now available and fully operational. GRAS is a 3D Monte-Carlo based radiation effects analysis tool based on GEANT-4 that sees its scientific applications growing-up. But, up-to-now, the lack of a user-friendly interface, especially regarding the CAD modeling, has limited its use in an industrial context. Also initiated by ESA and maintained by the SPINE community, SPIS is an open-source software dedicated to the modeling of spacecraft-plasma interactions. Based on a 3D PIC model, widely used, SPIS became the de-facto European standard in charging analysis. Via several ESA projects (ElShield, CIRSOS, 3DMICS, ... ) and an internal R&D done at ONERA, SPIS has been recently extended to internal charging effects, down-stream to radiations analysis.
However, the driving of such multi-steps modeling chain as a whole remained complex and arid, especially by the lack of adapted and unified open source pre-processing tools. Moreover, the integration of such simulation tools with other engineering systems, like B-Rep based CAD applications used in the industry, was still very challenging.
A strong internal R&D effort has been performed at Artenum to address these issues by the development ab-initio of a self-consistent set of new and dedicated software and user interfaces to set-up and control GEANT-4 based models.
EDGE, for ExtendeD Gdml Editor, is a CAD tool able to create, edit and visualize geometries in GDML format, used as input of GRAS. Embedding a 3D view and offering a rich GUI, EDGE not only allows creating, editing and importing geometrical systems, but also offers the possibility to graphically create material properties and assign them to the geometry. Using the CAD capabilities of the Keridwen IME, EDGE also builds a link with industrial CAD tools with the possibility to import STEP-AP 203/214 files, convert GDML models into an equivalent geometric model for radiation analysis and export them to Gmsh (.geo) format used by SPIS and/or various mesh formats.
This is completed by a dedicated WYSIWYG user interface, or Radiation Manager, allowing to fully set-up a GEANT-4 simulation kernel, like GRAS, including the loading of the geometry, the material attribution, the setting of particles sources and the simulation settings through a standard .g4mac script and the various geometrical support for scoring and data exchanges.
Integrated as a new OSGi bundle in the SPIS-IC IME, the Radiation Manager directly transfers computed data (e.g. deposited dose and charge) to the SPIS kernel for internal charging analysis.
To evaluate the relevance of the proposed approach, first tests have been perform on a basic and non space-validated but still realistic, in terms of complexity, electronic system with an ARM based computer board (i.e. simple Raspberry Pi card). In this test, the card has been initially imported from a pre-existing STEP-AP geometry file, converted by a surface tessellation and simplified with EDGE in order to build-up a model compliant with GRAS. Various simulations have been performed with GRAS, using the Radiation Manager, and considering different shielding configurations.
These first results have fully confirmed the relevance of the global approach and the possibility to model realistic and quite complex devices, starting from an industrial input CAD file. They also confirm that the EDGE, Radiation Manager, GRAS and SPIS-IC chain is operational and might be used in an industrial context. However, these first tests have also outlined several constraints on the used tessellation method for the stability and the relevance of GEANT4 simulations. These different results will be presented and discussed.
Primary author
Mr
Benjamin RUARD
(Artenum)
Co-authors
Dr
Amandine Champlain
(Artenum)
Mr
Arnaud Trouche
(Artenum)
Dr
Didier Falguere
(ONERA)
Mr
Julien Forest
(Artenum)
Dr
Pierre Sarrailh
(ONERA - The French Aerospace Lab)
