EFFECTS OF TYPE-I EDGE-LOCALIZED MODES ON TRANSPORT IN ASDEX UPGRADE

Particle and energy losses due to type-I edge-localized modes (ELMs) a nd 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 p uffing, impurity injection, variation of plasma current and heating po wer. 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 st ored energy encountered, e.g. in a plasma current scan. A good correla tion between pedestal pressure and stored energy is found for type-I E LMy discharges.