Abstract. This paper describes experimental analysis of different phases of ECRH H-mode discharges on COMPASS-D, from L-H transition trigger to steady state. Comprehensive high-resolution measurements of the transport barrier region have enabled significant progress to be made in assessing H-mode trigger mechanisms, as well as clarifying the evolution of the local electric field and its shear. Stationary ELMy H-modes are achieved at high with good confinement, and dimensionless scaling over a range of is presented.
IAEA 2001