Magnetic surfaces of toroidal stellarator with longitudinal current in plasma

The article deals with influence of toroidality and longitudinal current on the shape of magnetic surfaces of a three-turn stellarator. The plasma pressure effects are taken into account. It is shown that with an increase in longitudinal current in plasma under regime of similar rotations of the lines of force of longitudinal current and the external winding (the case of twisting) or with a rise in gas-kinetik pressure there occurs missing of the paraxial separatrices. The conditions for the missing of resonance rosettes inside a magnetic stellarator configuration are derived with the presence of current-carrying plasma taking into account its pressure. Whith an increase in longitudinal current and gas-kinetic pressure (the case of untwisting) the toridality effects lead to an essential rearrangement of the magnetic surfaces. The latter may by responsible for the anomalous quick loss of plasma in the threeturn stellarator which is observed in a number of experiments