musrSim simulation
Contents
This is the C++ source code for the musrSim simulation software which is intended to be a general tool for designing and simulating µSR spectrometers with high accuracy. To compile and run musrSim, the user must have a recent Geant4 (tested with v11.0.3 and v11.2.0) and ROOT installed (tested with v6-22-06 and v6-30-02, but the version should not be critical).
- The code is specifically tuned to simulate muon spin spectrometers.
- The code is maintained by the Laboratory for Muon Spin Spectroscopy at PSI.
Supported platforms
- Linux and any other decent OS that can run ROOT and Geant4.
Installation
Compile and install Geant4, we recommend the use of the following cmake flags
cmake -DCMAKE_INSTALL_PREFIX=/path/to/G4installation /path/to/G4source -DGEANT4_USE_QT=ON -DGEANT4_INSTALL_DATA=ON -DGEANT4_USE_OPENGL_X11=ON
We also recommend that you use view3dscene as a VRML viewer.
Following the installation of Geant4, initialise the Geant4 runtime environment before configuring or running musrSim. For a standard Geant4 installation this is normally done by sourcing the script installed with Geant4:
. /path/to/G4installation/bin/geant4.sh
The Geant4 data-set environment variables required by your installation must be valid after this step. If they are not, correct the Geant4 installation/environment rather than hard-coding musrSim-specific paths.
Clone the musrSim repository
git clone https://gitea.psi.ch/LMU/musrsim
then (see below for RedHat or other old systems)
cd musrsim
mkdir build
cd build
cmake ../
make -j8
make install
This will install the musrSim binary in /usr/local/bin, but it can be moved to any other directory in your PATH.
Running the tests
Tests are built by default. After configuring and building, run them with:
ctest --test-dir build --output-on-failure
Set -DBUILD_TESTING=OFF during CMake configuration to omit the test executables.
The regression suite currently covers steering-file parsing, process and volume
ID mappings, the muonium charge-state yield model over its documented energy
range, and the unpolarized muonium decay spectrum, isotropy, and energy
conservation. Tests carrying the physics label can be run separately with:
ctest --test-dir build --output-on-failure -L physics
To compare a modified build with an older build using identical event seeds and
the LEM run-4000 setup, build the musrRootOutputCompare target and run:
tests/compare_lem_versions.sh /path/to/baseline/musrSim /path/to/candidate/musrSim 500
The harness writes both simulations to temporary directories and compares the
logical ROOT contents exactly. Set MUSRSIM_ROOT_COMPARATOR when the comparator
is not available under tests/ beside the candidate executable.
Running the simulations
Prepare a file, filename.mac, with your beamline and spectrometer design following the instructions in the musrSim manual. Create a folder data and then run the simulation
musrSim filename.mac
Contact
Thomas Prokscha thomas.prokscha@psi.ch
Zaher Salman zaher.salman@psi.ch