Energy Confinement in Self-Organized Tokamak Plasma (without Transport Barriers)

Analysis of the highest energy confinement in tokamaks based on thermodynamic approach

“…When the input power is inconsistent with the self-consistent pressure profile, it results in a deviation of the pressure profile from the self-consistent profile and accordingly in the increase in the free energy F. The free energy increase results in the increase in the disturbed flux Γ 1 and of the coefficient κ = θ•(χ 0 + χ 1 ). The resulting flux Γ 1 aims to bring the pressure profile closer to the self-consistent pressure profile [4,16,17].…”

“…To calculate the thermal diffusivity coefficient κ 0 in SEC regime a series of the experiments was carried out and analyzed in the T-10 tokamak. Let us briefly describe the main results of experiments with the impurity gas puffing [3,4]. The dependence of the stored plasma energy at different powers of the additional ECR heating on radiation losses with different injected impurities, helium (He) and neon (Ne), was studied.…”

“…It was shown in [3,4] that, in fact, τ E depends on radiation losses at the plasma periphery rather than on the plasma density. As the working gas puffing increases, the flux of resonant charge-exchange neutrals on the wall raises that result to the * Author to whom any correspondence should be addressed.…”

“…It was shown in [3,4,16,17] that the experimentally observed self-consistent pressure profiles in a tokamak can be described within the framework of the nonequilibrium thermodynamics approach. This approach is successfully used to describe complex nonequilibrium systems in other fields of science, when the desired stable states correspond to the minimum free energy and represent the solution of the equation δF = δ(−θ•S + E) = 0, where S and E are entropy and energy respectively, and θ is some effective turbulent temperature.…”

“…In this paper, for calculation the thermal diffusivity coefficient, the plasma energy confinement in the SEC regime is analyzed for the T-10 tokamak. Experiments with the impurity gas puffing were considered, in which the improved energy confinement was achieved [3,4]. To describe the energy balance, the equation of the Smoluchowski type was used.…”