On Greenwald density limit in H-mode

摘要

The experimental Greenwald density limit in tokamak H-mode is explained from the requirements that in the edge transport barrier the radial pressure gradient does not exceed the ballooning stability threshold and the plasma collisionality corresponds to the transition from the plateau regime of neoclassical transport to the Pfirsch-Schluter one, where the edge temperature and plasma energy content decrease dramatically with increasing density.