Fig. 1. Schematic diagram of the CAT-1 device^[6]

Fig. 2. Trajectory of alpha particles in the equilibrium background magnetic field with maximum plasma specific pressure of βmax=10 (a), βmax=1 (b) (color online)

Fig. 3. Diagrams of the Poincaré sections of the resonant line field with n=0 (a) and n=1 (b) in the normalized r^-z^ plane of the cylindrical coordinates

Fig. 4. Trajectories in Cartesian (upper) and cylindrical (bottom) coordinates of alpha particles under different operating modes of the TSR coil (color online)

Fig. 5. The curves of the fraction of constrained particles versus flight time and flight distance under different operating modes of the TSR coil (color online)

Fig. 6. The trajectories in Cartesian (upper) and cylindrical (bottom) coordinates of alpha particle under the low-mode poloidal perturbation magnetic field (color online)

Fig. 7. The curves of the constrained particle fraction versus flight time and flight distance in the presence of a low poloidal mode number perturbation magnetic field (color online)