GPU ray tracing acceleration for optical photons in particle detectors - EIC-Opticks

The majority of time spent in the simulation of Cherenkov and other scintillation detectors is spent on optical-photon transport, a task that GPUs are designed to perform. We present EIC-Opticks, a fork of Opticks. We introduced event aggregation to drastically speed up photon transport simulation for low-to-moderate photon yield experiments. During the full Geant4 Monte Carlo simulation of a given detector, optical photon simulation is exported and simulated on GPU using the NVIDIA OptiX framework.

In the test case of the proximity focusing Ring Imaging Cherenkov detector, EIC-Opticks shows an order-of-magnitude speedup over multi-threaded Geant4, and a factor of up to 150 over single-threaded Geant4 CPU simulation. Event aggregation further reduces the per-photon simulation time by 3000. For easy install we provide a Spack package and containers.