High confinement mode

High-confinement mode or H-mode is an operating mode possible in toroidal magnetic confinement fusion devices - mostly tokamaks but also in stellarators. In this mode the plasma is more stable and better confined.

It was discovered by Fritz Wagner in 1982 during neutral beam heating of the plasma at ASDEX. It has since been reproduced in all major toroidal confinement devices and is planned in the operation of ITER. Its self-consistent theoretical description is a topic of current research.