Observation of floating potential asymmetry in the edge plasma of the SINP tokamak

Edge plasma properties in a tokamak is an interesting subject of study from the view point of confinement and stability of tokamak plasma. The edge plasma of SINP-tokamak has been investigated using specially designed Langmuir probes. We have observed a poloidal asymmetry of floating potentials, particularly the top-bottom floating potential differences are quite noticeable, which in turn produces a vertical electric field (E_v). This E_v remains throughout the discharge but changes its direction at certain point of time which seems to depend on applied vertical magnetic field (B_v).