Tokamak plasma self-organization and the possibility to have the peaked density profile in ITER

Abstract

The self-organization of a tokamak plasma is a fundamental turbulent plasma phenomenon, which leads to the formation of a self-consistent pressure profile. This phenomenon has been investigated in several tokamaks with different methods of heating. It is shown that the normalized pressure profile has a universal shape for a wide class of tokamaks and regimes, if the normalized radius ρ = r/(I p R/κB)1/2 is used. The consequences of this phenomenon for low aspect ratio tokamaks, the optimal deposition of additional heating, fast velocity of heat/cold pulse propagation and the possibility of obtaining a peaked density profile in ITER are discussed.

Tokamak plasma self-organization—synergetics of magnetic trap plasmas

“…There are three main fundamental phenomena defining the confinement of tokamak plasmas [14][15][16]:…”

“…In these regions higher values of ∇p are permitted. Let as recall the main features of the self-consistent pressure profile [14,15].…”

Explanation of Experimentally Observed Phenomena in Hot Tokamak Plasmas from the Nonequilibrium Thermodynamics Position

“…However, even when there is no radial distorting heat flux (i.e., when the plasma free energy has a minimum), there still is a significant level of turbulence and, therefore, a significant value of energy transport. Normalized pressure profiles in different tokamaks [7] and self-consistent profile pc [8] calculated from thermodynamic approach vs normalized radius ρ = r/(IR/B) 1/2 . The total heat flux Γ determined by the heating power deposited into the plasma can be represented as the sum of two fluxes: [7] and self-consistent profile p c [8] calculated from thermodynamic approach vs normalized radius ρ = r/(IR/B) 1/2 .…”

“…Normalized pressure profiles in different tokamaks [7] and self-consistent profile pc [8] calculated from thermodynamic approach vs normalized radius ρ = r/(IR/B) 1/2 . The total heat flux Γ determined by the heating power deposited into the plasma can be represented as the sum of two fluxes: [7] and self-consistent profile p c [8] calculated from thermodynamic approach vs normalized radius ρ = r/(IR/B) 1/2 . The total heat flux Γ determined by the heating power deposited into the plasma can be represented as the sum of two fluxes:…”

“…We offer another approach to explain the abovementioned experimental data, which is based on the idea of plasma self-organization. It is well known that tokamak plasma is turbulent and self-organized [3][4][5][6][7]. It was shown experimentally that the normalized pressure profile p N (ρ) is independent of any parameters.…”