Speakers
Description
Simulation of particle-matter interactions in complex geometries is one of
the main tasks in high energy physics (HEP) research. Geant4 is the most
commonly used tool to accomplish it.
An essential aspect of the task is an accurate and efficient handling
of particle transport and crossing volume boundaries within a
predefined (3D) geometry.
At the core of the Geant4 simulation toolkit, numerical integration
solvers approximate the solution of the underlying differential
equations that characterize the trajectories of particles in an
electromagnetic field with a prescribed accuracy.
A common feature of Geant4 integration algorithms is their
discrete-time nature, where the physics state calculations are
essentially performed by slicing time into (possibly adaptive) steps.
In contrast, a different class of numerical methods replace time
discretization by state variable quantization, resulting in algorithms
of an asynchronous, discrete-event nature. The Quantized State Systems
(QSS) family of methods is a canonical example of this category. One
salient feature of QSS is a simpler, lightweight detection and
handling of discontinuities based on explicit root-finding of
polynomial functions.
In this work we present a performance comparison between a QSS-based standalone
solver and combinations of standard fixed step 4th order Runge-Kutta (RK4) and adaptive step RK4/5 methods in the context of Geant4.
Our results show that QSS performance scales significantly better in
situations with increasing number of volume crossings. Finally, we
shall present the status of our work in progress related to embedding QSS
within the Geant4 framework itself.
| Primary Keyword (Mandatory) | Simulation |
|---|---|
| Secondary Keyword (Optional) | Algorithms |
