In a current rising phase of a shell-less toroidal device NOVA, it is observed that the current channel of the plasma is spreaded abruptly over the limiter. The time tcr required for this phenomenon to take place is proportional to the toroidal magnetic field. The characteristics of this motion of the current channel and related phenomena are studied. Finally a possible picture of the plasma in a current rising phase is described.
Microwave fusion reactors in superconducting cavities are discussed in some detail. It is emphasized that, although the break-even cannot be met at this moment, the experimental investigations of the plasmas in superconducting cavities will disclose many unknown phenomena, which are quite essential in the nuclear fusion research and the plasma physics.