CATAPULT: A CUDA-Accelerated Timestepper for Alpha Particles Using Local Tricubics

TL;DR

This paper presents CATAPULT, a GPU-accelerated timestepper for alpha particles in stellarator simulations, offering significant speed improvements and supporting complex magnetic field scenarios.

Contribution

The paper introduces a novel CUDA-based timestepper that accelerates Monte Carlo alpha particle simulations in stellarators, integrated into the firm3d Python package.

Findings

GPU implementation is significantly faster than CPU versions.

Successfully handles equilibrium magnetic fields and Shear Alfven Waves.

Validated on multiple stellarator examples for accuracy and speed.

Abstract

We introduce a CUDA-Accelerated Timestepper for Alpha Particles Using Local Tricubics (CATAPULT) for use in Monte Carlo calculations of alpha particle confinement in stellarators. Our GPU implementation is significantly faster than existing parallelized CPU implementations, and handles both equilibrium magnetic fields and Shear Alfven Waves. We test our implementation on several example stellarators to exhibit both the speed and correctness of our code. The source code is included in the firm3d Python package.