VCoRTEx (Virtual Cosmic Ray Tracker Experiment, or Virtual CoRTEx) is a simulation engine, built on top of Geant4, for the Pitt-CoRTEx muon detector. It serves multiple purposes:
-
To accurately model the generation and transport of photons inside the scintillator bars to the SiPMs
-
To interface with other software systems running on the detector (triggering, track fitting, data logging, etc.), for development and testing
-
To serve as an educational tool that provides insight into the Pitt-CoRTEx detector's inner workings
This project was developed as part of the Pitt-CoRTEx research group under Dr. Pranava Teja Surukuchi and Dr. Tae Min Hong, and as a final project for PHYS 1378 Introduction to Nuclear and Particle Physics (Spring 2026) at the University of Pittsburgh.
VCoRTEx is built using CMake and requires both Geant4 and ROOT. After installing these dependencies, proceed with the build
mkdir build && cd build
cmake .. -DCMAKE_PREFIX_PATH=/path/to/geant4-install -DCMAKE_INSTALL_PREFIX=/path/to/vortex-install
make -jN
make installwhere N is the number of system threads.
VCoRTEx can be ran in interactive mode, by not specifying a macro file
./vcortex_sim cor in batch mode
./vcortex_sim c batch.macWhere c is the configuration number (c=0 for full detector stack, c=1 for a single bar)
The VCoRTEx Geant4 application write photon hits to vcortex_output.root in the following format, with one TTree per run.
| Item | Description | Usage |
|---|---|---|
| x_mm | x position on SiPM face (mm) | N/A |
| y_mm | y position on SiPM face (mm) | N/A |
| energy_eV | photon energy (eV) | SiPM sim |
| time_ns | time after event start (ns) | N/A |
| detID | SiPM number (copy #) | SiPM sim |
| eventID | event number (particle #) | SiPM sim |
Some examples python scripts are included for simulation of SiPM response, and track fitting (WIP)
The NVIDIA OptiX/Opticks optical photon transport detailed in the proposal and presentation slides is not included in this repository due to build complexity. The simulation defaults to standard multithreaded Geant4 optical physics. Contact the author for details on the full implementation.