A novel high-performance computing algorithm, developed in response to the next generation of computational challenges associated with burning plasma regimes in ITER-scale tokamak devices, has been tested and is described herein. The Lorentz-orbit code for use in stellarators and tokamaks (LOCUST) is designed for computationally scalable modelling of fast-ion dynamics, in the presence of detailed first wall geometries and fine 3D magnetic field structures. It achieves this through multiple levels of single instruction, multiple thread parallelism and by leveraging general-purpose graphics processing units. This enables LOCUST to rapidly track the full-orbit trajectories of kinetic Monte Carlo markers to deliver high-resolution fast-ion distribution functions and plasma-facing component power loads. LOCUST has been tested against the prominent NUBEAM and ASCOT fast-ion codes. All codes were compared for collisional plasmas in both high and low-aspect ratio toroidal geometries, with full-orbit and guiding-centre tracking. LOCUST produces statistically consistent results in line with acceptable theoretical and Monte Carlo uncertainties. Synthetic fast-ion D-α diagnostics produced by LOCUST are also compared to experiment using FIDASIM and show good agreement.

一种新的高性能计算算法是为了应对与 ITER 规模托卡马克装置中燃烧等离子体制度相关的下一代计算挑战而开发的，已在本文中进行了测试和描述。用于仿星器和托卡马克 ( LOCUST )的洛伦兹轨道代码旨在在存在详细的第一壁几何形状和精细的 3D 磁场结构的情况下，对快离子动力学进行计算可扩展建模。它通过多级单指令、多线程并行和利用通用图形处理单元来实现这一点。这使LOCUST快速跟踪动态蒙特卡罗标记的全轨道轨迹，以提供高分辨率的快速离子分布函数和面向等离子体的组件功率负载。LOCUST已经针对突出的NUBEAM和ASCOT快离子代码进行了测试。对具有全轨道和引导中心跟踪的高深宽比和低深宽比环形几何形状的碰撞等离子体的所有代码进行了比较。LOCUST产生符合可接受的理论和蒙特卡罗不确定性的统计上一致的结果。LOCUST产生的合成快离子 D- α诊断也与使用FIDASIM 的实验进行了比较，并显示出良好的一致性。