Advanced Example ChargeExchangeMC
Responsible Geant4 Collaborator:Alexey Radkov
Cexmc stands for Charge EXchange Monte Carlo. The program was used to simulate real experiments in Petersburg Nuclear Physics Institute (PNPI, Russia).
Cexmc consists of several optional and mandatory modules, optional modules can be enabled or disabled in the makefile by setting dedicated macros. Modules may involve additional dependencies. In the following table the dependencies and related modules are shown.
||Optional||CEXMC_USE_PERSISTENCY||Persistency||Used when (de)serialization of events and run data|
||Optional||CEXMC_USE_PERSISTENCY||Main||Used when parsing command line arguments related to persistency module|
||Optional||CEXMC_USE_CUSTOM_FILTER||Custom filter||Used in custom filter engine|
|cernlib||Optional||CEXMC_USE_GENBOD||Main||User can choose native GENBOD() as phase space generator|
|CERN ROOT||Optional||CEXMC_USE_ROOT||Histogramming||Used for histogramming|
|CERN ROOT with Qt binding||Optional||CEXMC_USE_ROOTQT||Histogramming||Used for live histograms in Qt sessions|
The persistency module is compatible with a pretty old
(compilation was tested under Scientific Linux 4.8 with gcc 3.4.6 and boost version 1.32). Custom filter requires a newer boost as far as it uses modern
boost::spirit library which requires boost version 1.37 and higher.
Presence of CERN ROOT libraries is tested automatically in the makefile, but it is possible to disable or enable the histogramming framework manually using the flag CEXMC_USE_HISTOGRAMING in the makefile.
Compilation of visualization modules and interactive sessions depends on whether standard Geant4 macros like G4VIS_USE, G4UI_USE, G4UI_USE_TCSH and G4UI_USE_QT have been set.
boost is installed in a special path in your system then you may need to properly set environment variables BOOST_INCLUDE_PATH and BOOST_LIBRARY_PATH which denote directories where boost include files and libraries are located.
Simulation run modes
Run modes are set from command-line options. To see available command-line options type in terminal
cexmc -h or just
Here is list of simulation run modes categorized by type of interaction with user:
- Batch mode. The simplest mode without any interaction with user. No command line option is required.
- Interactive mode. The program provides an interactive shell. To run in the interactive mode command line option
-imust be specified.
- Graphical Qt mode. This mode is specified by command line option
List of run modes categorized by task:
- Straight mode (or Monte Carlo mode). The program will read preinit and init macros, then calculate acceptances and (optionally) save data in project files. Project files are saved in a directory defined by environment variable CEXMC_PROJECTS_DIR (or in the current directory if it is not defined), name of the project is specified by option
-w. Preinit and init macros are set by options
-mrespectively. In the straight mode preinit macro must be specified explicitly, as far as desired production model can be instantiated only in preinit phase.
- Replay mode (or Read project mode). In this mode the program will not use common Geant4’s event loop. Instead, it will sequentially read event data from an existing project and pass them into
CexmcEventAction::EndOfEventAction(). The read project is specified by option
-r. This mode is useful when the user wants to recalculate data from an existing project with different conditions (for example with different reconstruction parameters) or apply a custom filter. The results of run can be written again into another project.
- Show results mode (or Output mode). The program will output various data from an existing project (specified by option
-r). Type(s) of data are specified in option
-o. For example, to show results of a run user can specify
-orunin command line. To show events, geometry and run results user can specify