In a levitated magnetic dipole confinement device, the magnetic field excited by the Tilt-Slide-Rotate (TSR) or the Resonant Line Field (RLF) coils can disrupt the topology of the background magnetic field, thereby affecting particle confinement. Due to the magnetic field generated by the TSR coil disrupting the structure of the closed magnetic field lines of the background dipole field, alpha particles injected close to the TSR coil side experience rapid loss.

This study aims to investigate the effect of magnetic disturbances generated by TSR coils and RLF coils on the confinement of alpha particles generated by DD-³He catalyzed nuclear reactions in a background magnetic dipole field.

Firstly, a collision loss model based on the parameters of the China Astro-Torus No.1 (CAT-1) device was established. Secondly, an interchange mode stable background magnetic field was obtained by the Dipole Equilibrium Grad-Shafranov Solver (DEGS). Thirdly, the magnetic field disturbance was generated by the TSR coil and calculated using a line segment approximation method. And the poloidal magnetic field disturbance produced by the RLF effect was generated by adding a toroidal magnetic field with the same direction or two opposite directions in the background magnetic dipole field. Finally, the orbits of alpha particles in a magnetic field were simulated using the particle testing method.

Simulation results of the magnetic field with a low poloidal mode number by superimposing a toroidal magnetic field on the background magnetic dipole field show that the mode n=0 poloidal disturbance magnetic field maintains a higher confinement particle fraction than that of n=1 mode within 10 μs, and after the flight time of alpha particles exceeds 10 μs, the confined particle fraction in the n=0 mode rapidly decreases.

The magnetic field disturbances can cause rapid loss of alpha particles along an open magnetic field line, reducing the loss during high-energy alpha particle relaxation by controlling the operating current of the TSR coil and the RLF effect.