Investigation of inter-ELM pedestal profiles in ASDEX Upgrade

Integrated data analysis and equilibrium reconstruction on a millisecond time base are used to gain edge profiles with high spatial and temporal resolution. The measured radial electric field profiles for a series of discharges with different gas fuelling levels show their minimum at the position of maximal ratio of pressure gradient and density (∇ p / n ). The analysis of electron density and temperature profiles in between edge localized modes (ELMs) reveals a characteristic sequence of phases, starting with a fast recovery phase, a quiet pressure build-up phase and a strongly fluctuating phase before the next ELM breaks out. These phases are described in terms of profile development, the behaviour of maximal gradients as well as their positions.