Influence Of Plasma Rotation On Q=1 MHD Instability

In tokamak, the neutral beam injection usually causes plasma rotation and shear flow. The shear flow has a significant effect on two kinds of magnetohydrodynamic instability, tearing mode instability and Kelvin-Helmholtz instability. In this paper, the influences of q profile and poloidal rotation profile on the q= 1 tearing and the Kelvin-Helmholtz instabilities have been investigated numerically by using a magnetohydrodynamic model in cylindrical geometry.Chapter One is introduction. In this chapter, we briefly introduce the ITER project, tokamak devices and its magnetic field configuration. And we summarize the types of the MHD instability and the research methods as well.Chapter Two is the tearing mode instability and the Kelvin-Helmholtz instability theories. In this chapter we also deduce the equations about poloidal magnetic flux y/and the stream function?.Chapter Three is the main research content of this paper. First, the scal ings about growth rate ? and resistance are studied. We found that the rate of m/n=1/1 mode is ?1/1?SHp-1/2 and that the rate of m/n= 2/2 is ?2/2?SHp-3/5?SHp-1/2 (tearing mode domain), then ?2/2?SHp0 (K-H mode domain).About q profile, we find that the larger the core safety factor (q0?1) is, the easier suppression of the tearing mode is, but the larger the core safety factor (q0?1) is, the easier inspiration of the K-H mode is. We also find the smaller the magnetic shear is, the easier suppression of the tearing mode is, and easier excitation of the K-H mode is. As for the rotation profile, we found that when the shear layer position is on the rational surface, the tearing mode is more likely to be suppressed, but when the shear layer position is inside the rational surface the K-H mode is more likely to be excited. In addition, the smaller the shear layer width is, the easier suppression of the tearing mode is, and the easier excitation of the K-H mode is.