Observation of poloidal current flowed to the vessel after failure of vertical position feedback control in EAST Tokamak

Plasmas with vertically elongated cross-sections tend to be unstable to an axis-symmetric instability. This paper studies the magnetohydrodynamic equilibria in elongated plasmas after failure of vertical feedback control by using magnetic data for EAST device. Vertical forces on the vessel due to the induced polodial and toroidal currents are evaluated. The maximum force of the Fzpol in vertical displacement events for EAST designed parameters is given.