The simulation in this repository uses the DD4HEP framework in the EIC software container. You will need to download and enter this software container (Singularity and CVMFS need to be installed) to run the simulation:
curl --location https://get.epic-eic.org | bash
./eic-shell
The standard ZDC_Sampling type in the 'epic' repository doesn't support the
polyhedra shape, so we construct our Polyhedra_ZDC_Sampling type detector.
To use it, one needs to compile it first:
cmake -B build -S . -DCMAKE_INSTALL_PREFIX=install
cd build
make install
To make the new detector type available, add the newly built library to LD_LIBRARY_PATH:
source setup.sh
To run the simulation, simply do:
./run.sh
This will run 1000 events, with a single electron generated per event. The generated electron has an energy of 10 GeV, moves along the z-axis, and has its origin at (x,y,z) = (0,0,0). The default geometry is 'prototype.xml', to produce hits, one should make sure that the prototype is along the z-axis. The DD4HEP output is digitized using the Juggler software.
The simulation will produce a '.edm4hep.root' file, which contains all simulation information. What is interesting to us is only hit related information, specifically: cellID, energy and position. They are extracted by the make_tree.py script.
To run a more complicated simulation, one needs to provide their own steeringFile and compactFile. The steeringFile defines the beam profile and the compactFile defines the prototype geometry and position. Try
./run.sh -h
for more available options.
We are now using the JANA based eicrecon for reconstruction. To do that, one needs to compile the CALI plugin, which is not a standard eicrecon plugin yet. To compile it:
- compile and install eicrecon, and make it the default executable
cmake -S CALI -B CALI/build -DCMAKE_INSTALL_PREFIX=plugins
cd CALI/build
make install
- now, we can use the CALI plugin
eicrecon -Pplugins=CALI -Ppodio:output_include_collection=CALIRawHits,CALIRecHits input.edm4hep.root
As an example, to draw the total digitized energy deposit in the sensitive area per event, do the following:
root -l prototype_reco_e-_2_GeV.edm4hep.root
events->Draw("Sum$(HCALHitsReco.energy)")
The detector geometry is defined in this file. The prototype consists of 7 layers of hexagal cells and 13 layers of square cells. Each cell is surrounded by 3D-printed plastic frame. There are 4 blocks per layer, and 7 hexagal (4 square) cells per block.
The world volume is air. The prototype position is adjustable, by changing the x0/y0/z0 values.
To view the prototype, one can use the dd_web_display toolkit:
dd_web_display prototype.xml
Another method is to convert the xml file into gdml file, and then show it with ROOT
geoConverter -compact2gdml -input prototype.xml -output prototype.gdml # run this command with eic-shell
Root commands to show the prototype:
TGeoManager::Import("prototype.gdml") // root or GDML file
gGeoManager->SetVisLevel(10) // Increase it to get more detailed geometry
gGeoManager->GetTopVolume()->Draw("ogl")