Effects of type-I edge-localized modes on transport in ASDEX upgrade
Particle and energy losses due to type-I edge-localized modes (ELMs) and the effect of H-mode pedestal parameters on global confinement are studied for H-Mode discharges in ASDEX Upgrade. ELM frequency as well as particle and heat losses during ELMs are strongly affected by gas puffing, impurity injection, variation of plasma current and heating power. However the average power loss due to ELMs P-ELM = f(ELM)Delta W shows much less variation, and cannot account for the variations of stored energy encountered, e.g. in a plasma current scan. A good correlation between pedestal pressure and stored energy is found for type-I ELMy discharges.