Engineering analysis of JET operation

Abstract

Since 1994 the JET experiment has been operated with a divertor, with currents up to 6MA. Disruptions are generally accompanied by vertical plasma displacements giving rise to vertical forces at the torus. Vertical force swings up to 5MN were recorded at vessel supports. The forces are toroidally non-uniform, with peaking factors up to 1.8. Global sideways displacements of the torus, up to about 5 mm, were also recorded in a number of disruptions. They are interpreted as consequence of a large amplitude m=1, n=1 kink mode. Disruptions led to damage of some components inside and also outside the vessel, such as internal saddle coils, and beryllium evaporator heads.