musrSim simulation

Contents

This is the C++ source code for the musrSim simulation software which is intended to be a general tool to design and simulate µSR spectrometer with very 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 Gean4, set the correct environment variables. This can be done easily by editing /path/to/G4installation/bin/geant4.sh to uncomment the lines defining Geant4 data location:

export G4NEUTRONHPDATA=$GEANT4_DATA_DIR/G4NDL4.7
export G4LEDATA=$GEANT4_DATA_DIR/G4EMLOW8.5
export G4LEVELGAMMADATA=$GEANT4_DATA_DIR/PhotonEvaporation5.7
export G4RADIOACTIVEDATA=$GEANT4_DATA_DIR/RadioactiveDecay5.6
export G4PARTICLEXSDATA=$GEANT4_DATA_DIR/G4PARTICLEXS4.0
export G4PIIDATA=$GEANT4_DATA_DIR/G4PII1.3
export G4REALSURFACEDATA=$GEANT4_DATA_DIR/RealSurface2.2
export G4SAIDXSDATA=$GEANT4_DATA_DIR/G4SAIDDATA2.0
export G4ABLADATA=$GEANT4_DATA_DIR/G4ABLA3.3
export G4INCLDATA=$GEANT4_DATA_DIR/G4INCL1.2
export G4ENSDFSTATEDATA=$GEANT4_DATA_DIR/G4ENSDFSTATE2.3

Then run the following to setup the correct variables

. /path/to/G4installation/bin/geant4.sh

You will probably need to do that everytime you want to run the simulation or add the line above to your .bashrc.

Clone the musrSim repository

git clone https://zaher-salman@bitbucket.org/zaher-salman/musrsim.git

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 simulations

Prepare a file, finlename.mac, with your beamline and spectrometer design following the instruction in the musrSim manual. Create a folder data and then run the simulation

musrSim filename.mac

RedHat and old systems

For compilation on RedHat systems:

• Make sure that the gcc-toolset-13 package is installed

• Use the follwoing compilation command: scl enable gcc-toolset-13 'make -j8'

• Use CMakeLists_rhel8.txt: cp CMakeLists_rhel8.txt CMakeLists.txt

• If you have Root 6.30 use FindROOT_6.30.cmake: cp FindROOT_6.30.cmake FindROOT.cmake

Contact

Zaher Salman zaher.salman@psi.ch