Conductivity and transport in neon deuterium discharges in the PLT tokamak

Introduction of large amounts of neon into Ohmically heated deuterium discharges in the PLT tokamakl results in higher central electron temperature (Te(0) ≅ 3 keV) and values of electron energy containment time that are larger than in regular discharges at the same electron density (τEe = 44 ms at e = 2 × 1019 m−3). For steady-state discharges with high effective Z (∼ 5–8) the conductance is larger than that predicted by neoclassical theory by as much as a factor of two. Transport rates of hydrogen-like and helium-like ions can be fairly well approximated by assuming a diffusion constant of between 0.4 and 1 m2·s−1. Within experimental uncertainties the diffusion of hydrogen-like neon is the same for co- and counter-directed high-power neutral beams.