Kink Instabilities of a Toroidal Screw Pinch

Magnetic diagnostics: General principles and the problem of reconstruction of plasma current and pressure profiles in toroidal systems

“…We should also note that in quasi-helical systems, irrespective of their particular realization, the spectrum of the magnetic field contains only a few harmonics [48][49][50][51][52][53][54][55][56], and the amplitudes of only two or three of these are changed appreciably with growing β. Hence, also in this case, little information could be potentially extracted from magnetic measurements.…”

Numerical computation of high-beta toroidal diffuse equilibria

“…This letter presents a method of numerical computation for obtaining diffuse equilibrium configurations of the high-beta toroidal plasma with a free boundary. Sample equilibria for various types of the high-beta tokamak [11], the screw pinch with force-free fields [12][13][14], the reversed-field pinch [15,16], the belt pinch [17][18][19][20], and the doubletheta pinch [21,22] are discussed in the next section. The stability problem is not treated here.…”

“…For simplicity, selecting fj(i//) and gj(i/O to be linear functions of t//, we apply the method to some typical types of high-beta tori. In Refs [11,14], a simple surface current model, i.e. the sharp-boundary model, is used for both the high-beta tokamak and the screw pinch, and the screw pinch is distinguished from the high-beta tokamak by the existence of a force-free current outside the main plasma [14].…”

“…In Refs [11,14], a simple surface current model, i.e. the sharp-boundary model, is used for both the high-beta tokamak and the screw pinch, and the screw pinch is distinguished from the high-beta tokamak by the existence of a force-free current outside the main plasma [14]. Similarly we distinguish here the high-beta diffuse equilibria with a force-free current outside the main plasma in the circular cross-sectional wall from those with a vacuum magnetic field outside the plasma.…”