Influence of bootstrap current on confinement and MHD instabilities in tokamak plasmas

Summary form only given. Based on the principle of profile consistency and the /spl etasub 1/-mode induced anomalous transport model of G.S. Lee and P.H. Diamond (1986), the energy confinement and MHD (magnetohydrodynamic) instabilities in tokamak plasmas were investigated with the bootstrap current taken into account. To determine consistently the poloidal field, which is dependent on both ohmic heating and bootstrap current, an integral equation for the bootstrap current, was obtained under the condition of current feedback control; an equation describing the central plasma temperature was also derived. It is shown that bootstrap current has a significant effect on the plasma confinement. If the bootstrap current is 15-30% of the total current, the global energy confinement time increases by 20-45% and the maximum of related energy store is almost as much as twice the value without bootstrap current.