Abstract
A new plasma confinement method is proposed to sustain high temperature core plasma in surface magnetic field. Magnetic field is zero in core plasma region (complete β =1plasma). The bootstrap current driven by the pressure of plasma generates the magnetic field in an outside area of the plasma column. The magnetic field plays the role as the surface magnetic field to confine plasma. In addition, in an outside area of external coils, the magnetic field cancel the magnetic field produced by the external coils. It is possible, therefore, to be decreased the total energy of the system by the confinement of high beta plasma. Then, bootstrap transition to the complete β=1 plasma confinement configuration is possible if plasma is heated by sufficient power level. The possibility is confirmed by the energy computation of the magnetic field under the cylindrical coil group model. In addition, it was shown numerically by the one dimensional transport calculation, that the threshold power (lower bound) exist in the heating input to plasma for the bootstrap transition to the complete β=1 plasma confinement configuration. Moreover, detailed structure of the complete β =1 plasma confinement configuration is shown by the equilibrium calculation of an axisymmetric configuration. It is proposed that the LHD magnetic field configuration be suitable for complete β =1plasma confinement.
