Dynamics of Plasma Filling the Gap of a Module of the Plasma Opening Switch of the MOL Facility

The Baikal program aimed at the creation of a superhigh-power generator for experiments in the field of inertial thermonuclear fusion includes the development of a MOL facility for modeling the main principles of the generator structure. It is suggested to use a six-module plasma opening switch (POS) in an external magnetic field as the output power sharpener. The scheme of upgraded plasma guns of the module of the MOL facility's POS and the results of studying the dynamics of filling the POS gap with plasma transversely to an external magnetic field are presented. It is shown that, in the presence of a long (similar to 40 mu s) prepulse in this module, a POS cathode-anode closure with plasma along the force lines of the external magnetic field occurs within a time interval between the first turning-on of the plasma guns and the POS operation, which is hazardous for its operation. To eliminate this threat, it is proposed to increase the POS length to similar to 70 cm. On the basis of the results obtained, a simpler and more reliable solution of the prepulse problem is proposed.