The Pedestal

The steep-gradient edge region of an H-mode plasma that sets overall performance.

The H-mode pedestal is a narrow edge region of steep pressure gradient sitting atop the confinement. Its height strongly influences total performance, and its stability is tied to ELMs.

The H-mode pedestal is a narrow edge region of steep pressure gradient whose height, through profile stiffness, strongly sets the whole plasma's performance. Its stability is tied to peeling-ballooning modes and ELMs, which is why edge configuration choices like negative triangularity matter so much.