Computation of Two-fluid Flowing Equilibrium of Helicity-injected Spherical Torus Plasma

摘要

A two-fluid flowing equilibrium of a helicity-injected spherical torus (HI-ST) plasma in the more realistic region including a flux conserver and a coaxial helicity source is numerically determined by using the combination of the finite difference and the boundary element methods. It is found from the numerical results that magnetic configurations change from the high-q HI-ST (safety factor q > 1) with paramagnetic toroidal field and low-β (volume average β value, < β > ≈ 2 %) through the helicity-injected spheromak and reversed-field pinch to the ultra low-q HI-ST (0 < q < 1) with diamagnetic toroidal field and high-β ( < β > ≈ 18%) as the external toroidal field at the inner edge regions decreases and reverses the sign. The effects of the ion flow on the MHD equilibrium configurations are discussed.