The main features of self-consistent pressure profile formation

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 the T-10 tokamak in different experiments, excluding profiles with pronounced transport barriers. It will be shown that the normalized pressure profile can be expressed by the equation pN(r) = p(r, t)/p(0, t), over a wide range of plasma densities. It will also be shown that pN(r) is independent of the heating power and the deposition profile of electron cyclotron resonance heating. Experiments show that pN(r) depends only on the value of q at the plasma edge. During rapid current ramp-ups it has been demonstrated that the conservation of pN(r) is established during a time tc < 0.1τE, with τE the energy confinement time. It can be concluded that the self-consistent pressure profile pN(r) in tokamaks is linked to the equilibrium of a turbulent plasma.