Stable Confinement of High-Beta Collisionless Toroidal Plasmas

Abstract

High-$\beta$, collisionless, toroidal multipole equilibria with parameters $n=5\mathrm{}\times {10}^{13}$ ${\mathrm{cm}}^{-3\mathrm{}}$, $T_i=200\mathrm{}$ eV, $T_e=25\mathrm{}$ eV, and bridge $\beta =8\mathrm{}$% have been obtained in the University of California at Los Angeles dodecapole. The equilibrium is characterized by perturbed vacuum magnetic fields, flat internal pressure profile with sharp edge, and a steep hoop bridge profile 2 ion-gyroradii wide centered on the separatrix. The transition from diffuse profiles at low $\beta <1\mathrm{}$% to sharp profiles at high $\beta >~5$% is observed. A stable equilibrium is observed in excess of 400 Alfvén times.