Newest π simulations
This section will deal with the simulation of all flavour neutrino interactions within the SND@LHC software environment.
This recipe will require at a first step a .gsimple root file containing informations about incoming neutrinos from FLUKA simulations (FLUKA to gsimple part to be written) and a geometry file in GDML format converted from .root file.
Convert .root geometry file to .gdml file
The first step is to convert the geometry file containing all of the volumes involved in the simulation to the gdml format. This can be achieved in python with this script or alternatively in C++ with:
TFile * f = new TFile("<geofile>.root")
TGeoManager * geo = (TGeoManager*) f->Get("FAIRGeom")
geo->Export("<geofile>.gdml")Create .ghep file with GENIE
Once the .gdml geometry file has been obtained, GENIE can be used in order to generate the a .ghep file which will be needed by sndsw in order to propagate neutrino interactions. So one can run the following command from GENIE:
gevgen_fnal -f "${GSIMPLE_FLUX},,-12,12,-14,14,-16,16"
-g $GEOFILE
-t ${TARGET}
-L "cm" -D "g_cm3"
-n $NEVENTS # or alternatively -e $INTLUMI
-o ${OUTFILE}
--tune ${TUNE}
--cross-sections ${SPLINESFILE}.xml
--message-thresholds $GENIE/config/Messenger_laconic.xml
--seed ${SEED}In particular this will issue a .ghep file including ${NEVENTS} within the ${TARGET} volume using the ${SPLINEFILE} with the ${TUNE} specified
A more detailed description of the arguments accepted by gevgen_fnal can be found here:
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