Gas breakdown in the T-7 tokamak

Study of the initial stage of the discharge of the T-7 tokamak shows that when the magnetic field in the discharge chamber has a comparatively small transverse component (B/sub perpendicular/approx.10/sup -3/B/sub parallel/) the gas breakdown occurs in two stages. First, while the discharge current is low, the breakdown occurs along a helical magnetic line of force between upper and lower parts of a limiter in one cross section in the chamber. In the second stage, when the field of the current exceeds the transverse magnetic field, and a rotational transform arises, a toroidal electrodeless discharge occurs.