Linear Dielectric Response Theory Study Of Interactions Between Charged Particles And Magnetized Two-Component Plasma

The interactions between charged particles and plasma have been a great interesting topic due to its considerable importance for the study of material surface modification, inertial confinement fusion (ICF) driven by heavy-ion beams, and magnetic confinement fusion (MCF) heated by neutral beam injection (NBI). Especially, while NBI as application to heating, current drive and rotation drive was successfully proved in tokamaks, it has become a further concern. In this thesis, the interactions between energetic particles and magnetized two-component plasma have been investigated based on NBI.Taking into account the dynamic polarization effects of both plasma ions and electrons, the linearized Vlasov-Poisson equations are solved by the methods of unperturbed trajectory integral and space-time Fourier transform, and the dielectric function is obtained in magnetized two-component plasma. Wake effects and energy loss are investigated for a proton moving in magnetized two-component hydrogen plasma for cases with and without finite Larmor radius (FLR) effects. Special attention is paid to the polarization of plasma ions in the low particle velocity region and strong magnetic field, and the influence of FLR effects on wake effects and stopping power.Numerical results show that, the stopping power has two peaks named ion stopping and electron stopping near their own thermal velocities, due to the collective excitations of plasma ions and electrons respectively. For low velocity u/vTe<1, the dynamic polarization effects of plasma ion are obvious with strong magnetic field, and the ion stopping contributes mainly to the energy losses of the incident particle. For high velocity u/vTe>1, the electron stopping is dominate to in the present of weak magnetic field. Magnetic field enhances the stopping power definitely, but not for the electron stopping with strong magnetic effects. Besides, both electron stopping and ion stopping increase with plasma density increasing, but show strong decreases only on their own temperature.Meanwhile, influences of the projectile velocity, magnetic field and plasma parameters on induced potential are investigated furthermore. The results suggest that, as the incident velocity gets closer to the stopping peak position, the oscillation amplitude of the induced potential is greater. Both magnetic field and plasma density enhanced wake effects evidently. The electron temperature lessens the induced potential with high incident velocity, but increases it with low incident velocity, while the ion temperature shows contrary results. At last, influences of FLR effects of charged particles on wake effects and stopping power are studied. With FLR effects, on one hand, the wake effects and stopping power are weaker than predicted without. On the other hand, the stopping power is always enhanced with the increasing magnetic field, and the electron stopping is smaller than the ion one, in both strong and weak magnetic field. Furthermore, the maximum peaks of wake fields shift to the positions of Larmor radius of the test particle x=a, while locate at x=0 for the case without FLR effects. Finally, we also find that the FLR effects make the electron stopping peak shifting to a high velocity region when electron temperature increases and to a low velocity region with ion temperature increasing.