Electromagnetic model for finite element analyses of plasma disruption events used in the design phase of the COMPASS-U tokamak

• Published in: Fusion engineering and design 2021-06, Vol.167 (C), p.112369, Article 112369
• Main Authors: Hromadka, Jakub, Havlicek, Josef, Patel, Nisarg, Yanovskiy, Vadim, Patocka, Karel, Prevratil, Jan, Imrisek, Martin, Jaulmes, Fabien, Brooks, Arthur, Titus, Peter, Balner, Vojtech, Sestak, David, Panek, Radomir
• Format: Article
• Language: English
• Subjects: ANSYS; Assembly; COMPASS-U; Current quench; Disruption; Eddy currents; Electromagnetic forces; Electromagnetic model; Finite element analysis; Finite element method; Halo current; Passive stabilizing plates; Plasma disruptions; Plates; Thermal quench; Tokamak devices; Vacuum vessel; Vertical displacement event; Vertical forces; Vessels
• ISSN: 0920-3796; 1873-7196
• DOI: 10.1016/j.fusengdes.2021.112369

•Electromagnetic model of plasma disruption events in the COMPASS-U tokamak.•Methodology of selection the most demanding disruption sequences on the VV assembly.•The model predicts up to 1.3 MA of toroidal current induced in the VV.•Vertical force on the VV assembly is expected up to 4.1 MN during disruptions. Large electromagnetic forces acting on the vacuum vessel and passive stabilizing plates of the COMPASS-U tokamak (R = 0.894 m, a = 0.27 m, BT ≤ 5 T, IP ≤ 2 MA) due to disruption events are expected during its operation. An electromagnetic model based on the finite element method was developed using ANSYS software to determine the maximal possible forces on the vacuum vessel assembly that might occur. The effects of current quench, thermal quench, vertical displacement events and halo currents are all incorporated in the model. The toroidal eddy currents, the poloidal eddy currents (caused by thermal and current quench) and the poloidal halo current are taken into account. The model predicts that the induced toroidal current can reach the value up to 1.33 MA in the vacuum vessel shell and the value up to 0.52 MA in the passive stabilizing plates. Vertical force up to 4.1 MN acting on the entire vacuum vessel assembly can be expected and force up to 2 MN acting on the stabilizing plates, in particular. The results of the presented electromagnetic model are part of the load specification for the mechanical design of the vacuum vessel assembly of the COMPASS-U tokamak.