GORAD (Geant4 Open-source Radiation Analysis and Design) Advanced Example

First release : September 2020 with Geant4 version 10.7
Author : Makoto Asai (SLAC National Accelerator Laboratory)

GORAD

Introduction

Gorad (Geant4 Open-source Radiation Analysis and Design) is developed as a turn-key application for radiation analysis and spacecraft design built on top of Geant4. Simulation geometry should be provided in the form of GDML.

Gorad is controlled by UI commands, and it works both in interactive mode with Qt window and in batch mode with an input macro file.

The current Gorad requires Geant4 version 10.7 (release of December 2020). It does not work with earlier version of Geant4. Geant4 has to be installed with multithreading mode and GDML interface enabled. Qt is also recommended for the use of Gorad in interactive mode. Geant4 GDML interface requires Xerces-C++ version 3 or higher. Xerces-C++ has to be compiled with the same compiler Geant4 is compiled. Please refer to the Geant4 installation guide for enabling these options.

Building and running Gorad

To compile and run Gorad, all the Geant4 environment variables have to be properly set. Use the shell script in the Geant4 installation directory.

Compilation of Gorad requires cmake and make same as the compilation of Geant4 itself.

$ source $G4INSTALL/bin/geant4.(c)sh
$ cmake .
$ make -f Makefile

To run Gorad in interactive mode,

$ ./gorad

and then, in the keyboard input field, type

/control/execute _macroFile_

The user may also use any UI commands shown in the left side menu of the Qt window.

To run Gorad in batch mode,

$ ./gorad _macroFIle_

Sample macro file

Associated macro file "run.mac" can be used for both interactive mode and batch mode. It uses a simple cone-shaped geometry (simpleCone.gdml) and King Solar Proton Fluence model (https://doi.org/10.2514/3.62088).

It employs both primary particle generation biasing and geometry importance biasing. This sample macro file defines a probe filled by water located at the center of the world volume with dose and flux scorers.

If this sample macro file is used in interactive mode, it also sets up visualization (through vis.mac). After executing this sample macro, the user can start an event loop with /run/beamOn command.

If this sample macro file is used in batch mode, it defines 4 histograms. After the event loop, These histograms are dumped to corresponding files and also plotted to a Postscript file. Scores of the dose and flux scorers are also dumped into an output file. In batch mode, this macro executes one million events.

Gorad manual and additional GDML file

Detail description of the sample macro file and available alternative commands are described in the full manual GoradManual_v10.7.pdf.

Additional sample GDML file of partial and simplified Orion Spacecraft is available here (~22MB). This is a sample input and it is not mandatory to execute Gorad.

Acknowledgements

Development of Gorad is funded by NASA Johnson Space Center (JSC) under the contract NNJ15HK11B.