PTC: Full and Drift Particle Orbit Tracing Code for α Particles in Tokamak Plasmas

Abstract

Fusion born α particle confinement is one of the most important issues in burning plasmas, such as ITER and CFETR. However, it is extremely complex due to the nonequilibrium characteristics, and multiple temporal and spatial scales coupling with background plasma. A numerical code using particle orbit tracing method (PTC) has been developed to study energetic particle confinement in tokamak plasmas. Both full orbit and drift orbit solvers are implemented to analyze the Larmor radius effects on α particle confinement. The elastic collisions between alpha particles and thermal plasma are calculated by a Monte Carlo method. A triangle mesh in poloidal section is generated for electromagnetic fields expression. Benchmark between PTC and ORBIT has been accomplished for verification. For CFETR burning plasmas, PTC code is used for α particle source and slowing down process calculation in 2D equilibrium. In future work, 3D field like toroidal field ripples, Alfvén and magnetohydrodynamics instabilities perturbation inducing α particle transport will be analyzed.