Development of GPU-Accelerated Spin Tracking Algorithms for the nEDM@SNS Experiment*

The neutron electric dipole moment (nEDM) experiment at the Spallation Neutron Source (nEDM@SNS) will utilize polarized ³He and ultra-cold neutrons (UCN) in a pair of measurement cells filled with superfluid ⁴He to place a new limit on the nEDM down to 2-3x10^-28 e·cm. Any deviations in the expected precession frequency of the ³He or UCN need to be understood from simulations to the nanohertz level to support the experimental precision goals. This necessitates large-scale datasets, ∼50 million particles each, to validate theory models within the experimental apparatus. Generating these datasets motivated the development of high-performance parallel integration routines that leverage graphics processing units (GPUs). A discussion of the adaptation of spin-integration to GPUs will be presented along with a quaternion-based spin integration algorithm optimized for the free-precession mode of the nEDM@SNS experiment.