Preliminary Calculation of Electromagnetic Loads on Vacuum Vessel of HL-2M

For a robust design of vacuum vessel of HL-2M, the electromagnetic (EM) loads have to be understood clearly. In this paper, some crucial transient events, such as plasma major disruptions (MDs), vertical displacement events (VDEs), fast discharge of toroidal field (TF) coils, have been investigated to evaluate the eddy currents and EM forces on vacuum vessel and in-vessel components. The results show that the eddy currents depend strongly on the current decay time, and the maximum toroidal eddy current flowing in the whole vessel can reach up to 2.4 MA during MDs that is close to the plasma current. Large symmetric radial forces and a net vertical force on vessel shells could be caused by these transient events. Combination of eddy currents in in-vessel components and toroidal field could twist the copper plates and other internal parts, however, if these plates are supported and connected carefully, the twist moments will not have a big e®ect on the vessel shells and vessel support.