Scalings and Plasma Profile Parameterisation of ASDEX High Density Ohmic Discharges

Abstract

High density ($.3<\bar{n}/10^{20}{\mathrm{m}}^{-3}<.8$), low $q_a$ ($1.9<q_a<3.4$), Ohmic discharges from the ASDEX experiment is analysed statistically. Bulk parameter scalings and parameterised temperature and density profile shapes are presented. The total plasma kinetic energy, assuming $T_i=T_e$, scales as ${\bar{n}}^{.54\pm .01}{I_p}^{.90\pm .04}$ and is almost independent of $B_t$. The electron temperature profile peaking factor scales as $T_0^{3/2}/<T^{3/2}>=.94(\pm .04){q_a}^{1.07\pm .04}$ in close agreement with the assumption of classical resistive equilibrium. In the inner half of the plasma, the inverse fall-off length for both temperature and density has a strong dependence on $q_a$, with the temperature dependence being more pronounced. Outside the half radius, the $q_a$ dependence disappears but the density profile broadens near the edge with increasing plasma current.