GRAS (Geant4 Radiation Analysis for Space)

GRAS is a Geant4-based tool enabling common radiation analyses types (TID, TNID, fluence, SEE, path length, charge deposit, dose equivalent, equivalent dose, radiation detection response, imaging sensor background,...) in generic 3D geometry models.

GRAS draws from the strength of Geant4 in particle-matter interaction physics modelling and geometry description, and augments it with ease of use in defining typical use cases for radiation analyses, from dosimetry to single event effects and detector response.

Both traditional Forward (Direct) Monte Carlo and Reverse (Adjoint) MC are available as options.

Input instructions are provided to GRAS via text files (macros) in Geant4 UI text format. Generic geometry models are input in GDML (or GMSH) format, which can also be used as exchange formats for complex CAD models. Simpler models can also be created with macro commands only, with the built-in MULASSIS or GEMAT modules. Output is provided to text files in CSV format, and optionally to ROOT files.

The main GRAS SW design requirements are flexibility and modularity of the application. Thanks to flexibility GRAS can be used for obtaining a variety of simulation output types for generic (GDML or C++) 3D geometry models, avoiding the creation of a new tailored C++ Geant4-based application for every new project. Thanks to a modular design, the GRAS analysis type capabilities can be easily extended by advanced users.

If you are willing to contribute to the development of the tool with suggestions, user requirements, bug fixes or some new code, you can contact us through the ESSR site.