Discharge development in a tokamak with a slowly increasing vortical field in the prebreakdown phase

This letter reports the first results of an experimental study of the initial stage of the discharge in the FT-2 tokamak (major radius of 55 cm, limiter radius of 8 cm, toroidal magnetic field 3.35 kG). A system of programmable control fields makes it possible to change the magnitude and direction of the transverse magnetic field during the discharge at a low inductive coupling with the plasma turn. (AIP)