Plasma position control in SST1 tokamak

For long duration steady state operation of SST1, it would be very crucial to maintain the plasma radial and vertical positions accurately. For design ing the position controller in SST1 we have adopted the simple linear RZIP control model. While the vertical position instability is slowed down by a set of passive stabilizers placed erased to the plasma edge, a pair of in-v essel active feedback coils can adequately control vertical position pertur bations of up to I cm. The shifts in radial position arising due to minor d isruptions would be controlled by a separate pair of poloidal field (PF) co ils also pieced inside the vessel, however the controller would ignore fast but insignificant changes in radius arising due to edge localised modes. T he parameters of both vertical and radial position control coils and their power supplies are determined based on the RZIP simulations.