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

The extrapolation from to-day tokamaks to ITER dimension hitherto remain to be very far. We can't do such extrapolation with the help of scaling built without deep understanding of the physical processes. The main process in the turbulent plasma is its self-organization. Transport coefficients may be changed in plasma in a wide range by changing of the instabilities level. This permit plasma to build the most stable under given external impacts energy distribution profile, i.e., plasma pressure self-consistent profile. This process cannot be realized only in the regions, where the turbulent transport value is not enough for the p(r) regulation. The enhanced grad p appears here. We call these regions 'transport barriers'. The plasma pressure self-consistent profile and transport barriers are two main factors, which determine the plasma pressure profile. At T-10 tokamak the phenomenon of plasma pressure self-consistent profile was investigated and it was shown that normalized plasma pressure does not depend on any plasma parameters if we normalize the minor radius to the radius r_c = (IR/kB)^1/2, ρ r/rc, k is plasma elongation coefficient, I plasma current, R major radius and B magnetic field strength. In this case p(ρ)/p(0) practically the same for T-10 and JET if in given shot there was not pronounced ITB. The process of p(ρ) restoration very fast and links to plasma minor radius equilibrium. Now we can predict the self-consistent pressure profile for ITER, which can be changed by ITB formation only. As we expect in ITER the peaked power deposition profile, and so the peaked temperature profile, we can conclude that density profile will be flat even in the low-collisionality case. (author)