Magnetic measurements of plasma configuration parameters in a tokamak

Abstract

as compared with that in single-antenna operation, for the same net power. On the other hand, the radiation in in-phase operation is enhanced as compared with that in single-antenna operation. As a result of the reduction of the radiation loss by ICRF heating with phase control, the maximum attainable density without disruption is increased compared to that in the Ohmic heating phase. The remarkable differences in metal impurity emission and radiation loss are closely related to the amount of radiated power with parallel wavenumber near k tt = 0. The metal impurities are released by a mechanism closely related to the radiated power near k,, = 0; on the other hand, the light impurities are released by a different mechanism.

Tokamak equilibrium reconstruction using Faraday rotation measurements

“…We only consider the first group here. The methods in this group [1][2][3][4][5][6][7][8] from one another in the numerical algorithms and in the type of measurements used. All methods use magnetic measurements (\jj and B) close to the vessel wall; some methods, in addition, use pressure profiles [3], diamagnetic signals [7], soft X-ray measurements [6] or the value of the safety factor on axis q 0 [ 1 ] for reconstructing the equilibrium.…”

“…The methods in this group [1][2][3][4][5][6][7][8] from one another in the numerical algorithms and in the type of measurements used. All methods use magnetic measurements (\jj and B) close to the vessel wall; some methods, in addition, use pressure profiles [3], diamagnetic signals [7], soft X-ray measurements [6] or the value of the safety factor on axis q 0 [ 1 ] for reconstructing the equilibrium. In several of these studies it has been shown that the use of additional measurements (other than \p and B) allows a more accurate solution to be found, in the sense that the number of source function parameters that can be reliably determined is increased.…”

Surface Morphology of Tl2Ba2Ca2Cu3Oy Thin Films Prepared by Thallium Diffusion Process

“…Although little supported by published results [3][4][5], optimism about this was taken up by stellarator researchers [13][14][15][16][17], among whom attempts to gather evidence in favour of a positive answer still continue [6][7][8]. Earlier such attempts were made with a strong belief in a positive outcome, later with reinsuring reserves (leaving, however, freedom even for mutually exclusive conclusions), but always along the same lines, prescribing different profiles first and then demonstrating that they correspond to different amplitudes of measurable magnetic quantities.…”

“…The formulation of this problem is simple: Is it possible to determine the plasma current distribution and/or the plasma pressure profile from external magnetic measurements? The very statement of the question [1][2][3][4][5] shows the hope for a positive answer that until recently has determined the style of some publications [6][7][8], although the 'conservative' majority gave up this hope a long time ago [9][10][11][12].…”

Toroidal plasma equilibrium with arbitrary current distribution

“…The profiles of toroidal current J v and dP/dY are expected to be very similar (Kuznetsov et al 1986). It seems that in general the current distribution is not a linear function of T. Thus the self-consistent Grad-Shafranov equation is a nonlinear elliptic equation containing an unknown function of X V. For tokamakplasma conditions the solution appears to be unique (Field & Papaloizou 1977) if Dirichlet's boundary condition is assumed.…”