DEPENDENCE OF THE H-MODE PEDESTAL STRUCTURE ON ASPECT RATIO

We report on the progress of a set of experiments between DIII-D, MAST, and NSTX to determine the aspect ratio dependence of the pedestal. The pedestal-top electron collisionality νe ~ 1 was matched in all three devices, as was the pedestal-top normalized ion gyroradius ρi* ~ 0.015. The goal of this set of experiments is to assess the pedestal widths and gradients, as well as the edge stability of each set of discharges. While substantial progress has been made toward this goal, the final answer awaits further analysis. The status of experiments and analysis on each machine is therefore described.