A new thermography system with high time resolution was put into operation at ASDEX-Upgrade and is routinely used to determine the energy flux onto the lower diverter plates. The measurements allow the power deposition to be chamcterized during dynamic events such as ELMS and disruptions, as well as the asymmetry of the inboardloutboard power load. A power balance is set up even during single discharges and the losses are found to be fairly equal to the power input.

This paper describes experiments with highly shaped JET H-mode plasmas, which were directed to developing regimes where Type I ELMs are replaced by other edge relaxations, while maintaining the pedestal pressure of Type I ELMy H-modes. It was found that Type II ELMs coexisted with Type I, up to densities of the order of the Greenwald limit, where Type III ELMs appear, and the good confinement was lost. Only at the highest edge collisionality was it observed that Type II ELMs completely replace Type I. At high β p and q 95 , 'grassy' ELMs replace Type I completely. The MHD spectra characteristics for grassy ELMs are significantly different from those of Type II ELMs. This paper details the experiments, briefly compares the results to those obtained elsewhere and suggests open lines of investigations for the assessment of the potential of grassy ELM regimes as an ELM mitigation technique.

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