Modelling of dense and cold divertor plasma in D-III☆

Abstract With single-null poloidal divertor discharges in D-III, very dense and cold ( n e ⩾ 1× 10 14 cm −3 , T e ∼ 4 eV ) divertor plasmas were observed. A numerical code has been developed to understand the mechanisms of the high density divertor. The divertor plasma code solves the equation of continuity, momentum and energy. The particle, momentum and energy source/sink terms are calculated by a neutral code which is solved consistently with the plasma parameters. The radiative cooling by oxygen and particle shielding/recycling at the main plasma scrape-off is also taken into account. The code calculation provides a good fit to the experimentally observed electron temperature, density, particle flux and radiative cooling power.