The effect of plasma shape variation (in particular, variation of the upper
and lower triangularity delta) on edge localized modes (ELMs) and H-mode p
edestal properties in ASDEX Upgrade is reported here. Strongly shaped plasm
as (high delta) show an increased edge pressure gradient and, without exter
nal gas puff, type-I ELMs generally have larger losses and lower frequency
than in plasmas with low delta. With external gas puff; ELM losses at high
delta are reduced and in the same range as found for low delta. The average
ELM power loss is a constant fraction of the total loss power, independent
of triangularity. The width of the steep electron temperature and pressure
gradient zone remains essentially constant at low delta while at high delt
a it shows a variation inconsistent with a poloidal gyroradius scaling. The
edge pressure gradient and the pedestal pressure scales strongly with plas
ma current and triangularity. In type-I ELM H-modes, the pedestal pressure
is directly related to the global stored plasma energy, independent of plas
ma shape.