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The flux-conserving tokamak model suggested that rapid heating would yield equilibria with high relative energy density {(3 = 2p/B 2 ) while nonetheless allowing control over q> the so-called safety factor for instability within the ideal magnetohydrodynamic plasma model. In this study, we show that this is adequate to provide stability to /3 values of 10%, if there is a superconducting metal shell in the vicinity of the plasma.

Articles you may be interested inOverview of equilibrium reconstruction on DIII-D using new measurements from an expanded motional Stark effect diagnostica) Rev. Sci. Instrum. 79, 10F518 (2008); Equilibrium reconstructions of reversed-shear discharges based on motional Stark effect measurements Rev. Sci. Instrum. 68, 392 (1997); 10.1063/1.1147837Equilibrium qprofile determination and stability analysis from magnetic field pitch angle measurements using motional Stark effect polarimetry Rev.The motional Stark effect (MSE) diagnostic has been used to obtain accurate measurements of the internal magnetic pitch angle tan-1(Bz/B r ) in finite-pressure tokamaks. The MSE data, together with external magnetic probe data, are used to reconstruct self-consistently the equilibrium safety factor (q) profile and, hence, the plasma current density, in the Tokamak Fusion Test Reactor (TFTR) [Plasma Phys. Controlled Nucl. Fusion Res. 1, 51 (1986)] and the Princeton Beta Experiment-Modified (PBX-M) tokamak [Phys. Fluids B 2, 1271]. An efficient computational scheme, based on an inverse coordinate representation of the magnetic field, has been developed to solve the coupled nonlinear equations describing both the magneto hydrodynamic (MHD) equilibrium and the q profile, which best match all the experimental data.

A simple model for drift-thermal instability-induced turbulence is derived and studied both analytically and numerically. Both nonlocal, nonlinear analytical calculations and three-dimensional computations are used. Potential and temperature fluctuation levels and radial correlation lengths are calculated and compared to numerical results. The saturation mechanism and the role of a fluctuation-generated shear flow are elucidated. The numerical calculations are used to obtain spectra and correlation lengths. A detailed comparison of analytical and numerical results is given.

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