Particle confinement improvement during 2.45 GHz lower-hybrid current-drive experiments

Abstract
Particle confinement behavior during 2.45 GHz lower‐hybrid current drive has been investigated on the Versator II tokamak [Phys. Fluids 2 9, 1985 (1986)]. It is found that during combined Ohmic and rf current drive the global particle confinement time τp increases by up to a factor of 2 compared to purely Ohmically driven discharges, as observed in earlier 800 MHz experiments at lower densities n̄e ≤6×1012 cm3. In the present experiments, τp increases have been observed at densities up to n̄e =2×1013 cm3.