Particle confinement during lower-hybrid current drive in the Versator 2 Tokamak

Increases in average density were observed during lower hybrid current drive (LACD) on the Versator II Tokamak and in other LHCD experiments where inductive and lower hybrid current drive are combined. Results of an extensive study of this density increase are presented showing that the increase is the result of an improvement in particle confinement time, tau/sub p/, compared to ohmic discharges with comparable parameters. The improved confinement appears when the Parail-Pogutse relaxation mode is stabilized during LHCD.