HGCal Tile

GEANT4-based simulation of CE-H HGCal scintillator tile.

Installing

The program can be can be installed in two methods. One is a standalone package meant to be used for event display and debugging. The other is to be compiled under CMSSW for for batch running and plotting.

For standalone installation (on hepcms.umd.edu or any Linux machine). The source command is only needed if you do not already have Geant4/ROOT installed on your system.

git clone https://github.com/yimuchen/HGCal-Dimple-Tile.git HGCalTileSim
cd     HGCalTileSim
source ./g4env.sh # If you do not have Geant4 already installed
cmake -DCMAKE_C_COMPILER=$(which gcc) -DCMAKE_CXX_COMPILER=$(which g++) .
cmake --build .

For the CMSSW installation, run the commented command if you want to use the inbuilt plotting scripts.

source /cvmfs/cms.cern.ch/cmsset_default.sh
export SCRAM_ARCH=slc6_amd64_gcc700
cmsrel CMSSW_10_3_1_patch1
cd CMSSW_10_3_1_patch1/src
cmsenv

git clone https://github.com/yimuchen/HGCal-Dimple-Tile.git HGCalTileSim
git clone https://github.com/yimuchen/UserUtils.git UserUtils
scram b

Single event running

For the interactive running, run the command following commands

./bin/LYSim
#$CMSSW_BASE/bin/${SCRAM_ARCH}/LYSim_Session  # In CMSSW

You should be greeted with the Geant4 prompt and a detector viewing window. You can alter detector parameters from using the many /LYSim commands

/LYSim/SetDimpleIndent 1.5 mm
/LYSim/SetPhotonMult 0.01

and run a number of event via the command:

/run/beamOn 10 # 10 Events

You can then browse the events in the viewing window. After you have closed the program, you can also see the saved results in the Interactive_Session.root file.

For debugging, run the command:

./bin/LYSim DEBUG
#$CMSSW_BASE/bin/${SCRAM_ARCH}/LYSim_Session DEBUG  # In CMSSW

In this setup, the particle source is a single optical photon source that one can set the position and direction:

/LYSim/Debug/SetParticlePosition 0 0 -1 mm
/LYSim/Debug/SetParticleDirection 0 5 10

Bulk running

In the CMSSW, one has can run the program $CMSSW_BASE/bin/${SCRAM_ARCH}/LYSim_SquareTrigger with multiple options:

>> $CMSSW_BASE/bin/slc6_amd64_gcc700/LYSim_SquareTrigger --help
  -h [ --help ]                     print help options and exit program

Running a run with a certain geometry:
  -x [ --beamx ] arg (=0)               x center of beam [mm]
  -y [ --beamy ] arg (=0)               y center of beam [mm]
  -w [ --beamwidth ] arg (=0)           width of beam [mm]
  -r [ --dimplerad ] arg (=3)           Dimple radius [mm]
  -d [ --dimpleind ] arg (=1.5)         Dimple indent [mm]
  -W [ --sipmwidth ] arg (=1.3999999999999999)
                                        SiPM active width [mm]
  -R [ --sipmrim ] arg (=0.40000000000000002)
                                        SiPM Rim width [mm]
  -S [ --sipmstand ] arg (=0.29999999999999999)
                                        SiPM Stand height [mm]
  -a [ --absmult ] arg (=1)             Multple of inbuilt absorption length
  -m [ --wrapreflect ] arg (=0.98499999999999999)
                                        Wrap reflectivity
  -N [ --NEvents ] arg (=1)             Number of events to run
  -o [ --output ] arg (=test.root)      output file

This will generate a root file of a single configuration with many number of events (it takes about 2-4seconds for each event so estimate your runtime accordingly). For example:

$CMSSW_BASE/bin/slc6_amd64_gcc700/LYSim_SquareTrigger --beamx 2.0 --beamwidth 1.5 --NEvents 1000 --output mytest.root

will generate the file mytest.root with the muon beam hitting the tile at x=2.0 mm, y=0.0 mm, with a uniform square distribution with half-width of 1.5 mm, and will run a total of 100 events (~30 min runtime). The user is free to write your own scripts for generating the required scripts for running under condor. For a list of parameters, see the help commands.

Generating Condor scripts

The command:

python3 condor/SubmitJobs.py <options>

Will generated of bunch of .jdl files in the condor/results/condor directory for condor job submission. There is a program option corresponding to each of the geometric program options for LYSim_SquareTrigger, except this time, each program option inputs takes in an array. All combinations of all geometric options will be have its corresponding jdl file generated. The JDL files themselves are essentially running a single instance of LYSim_SquareTrigger.

Generating the Light-yield v.s. beam x graph

The command

$CMSSW_BASE/bin/$SCRAM_ARCH/LYSim_MakeLYvXGraph --inputfiles *.root --output graph.root

will take all the bunch of output file generated using the LYSim_SquareTrigger command, and use them to generate a Light yield verses beam x value graph, with different geometric configuration automatically listed in the Graph name. For details on the graph name, see the file Plot/src/LYvX_Common.cc.

Plotting the Light-yield v.s. graph

The command

$CMSSW_BASE/bin/$SCRAM_ARCH/LYSim_PlotLYvXGraph --inputfiles graph.root <geometric parameters>

takes the output of the MakeLYvXGraph command, and plots the graphs into a standard CMS plots format. One of the geometric parameters can be a list to put more than one geometric comparison in the same plot for comparison.