Distortion of Fast α-Particle Two-Dimensional Velocity Distribution Function due to the Transition of Particle Orbit by Nuclear Elastic Scattering in Magnetic Field Confinement

Abstract

The effect of nuclear elastic scattering (NES) on energetic alpha-particles two-dimensional (2D) velocity distribution function in a magnetic fusion device is examined by particle orbit simulation. Energetic alpha-particles exhibit an anisotropic 2D velocity distribution function, because the alpha particle loss reduces the amount of particles moving in a particular direction, and an alpha particle orbit depends on the initial direction of particle. When NES changes the direction of fast alpha particle motion, its orbit can be changed. It is shown that NES causes particle orbit transitions and changes the energetic alpha particles 2D velocity distribution function. We discuss the manner in which the distribution function is changed and how it affects the confinement of fast alpha particles.