Fast plasma dilution in ITER with pure deuterium shattered pellet injection

Abstract

JOREK 3D non-linear magnetohydrodynamic (MHD) simulations of pure deuterium shattered pellet injection in ITER are presented. Considering a 15 MA L-mode plasma with a thermal energy content of 36 MJ from the non-activated phase of ITER operation, it is shown that such a scheme could allow diluting the plasma by more than a factor 10 without immediately triggering large MHD activity, provided the background impurity density is low enough. This appears as a promising strategy to reduce the risk of hot tail runaway electron (RE) generation and possibly to avoid RE beams altogether in ITER, motivating further studies in this direction.