ELM-resolved divertor target power load studies were conducted for a wide range of discharge conditions in the JET tokamak. The magnetic configuration of these discharges was optimized for the fast divertor IR camera observing the outboard target. It is found that the ELM size estimated from the diamagnetic energy is not uniquely determining the ELM energy load at the divertor target. ELM mid-plane integral deposited power widths between 7 and 18 mm are observed, the inter-ELM widths lie in the range 2.5–6 mm. This ELM broadening is found to widen with ELM size. The temporal evolution of the ELM shape was characterized by rise and decay times. The ELM rise times are found to be in the range expected for ITER (250 µs), but the ELM decay is usually larger than assumed for the ITER design.
Features of spontaneous and pellet-induced ELMs on the HL-2A tokamak