Microsecond plasma opening switches in externally applied magnetic field

The plasma opening switch (POS) is a key element producing nanosecond high-voltage pulses in many pulsed power systems using inductive energy storage. For POS experiments with microsecond conduction times described in the paper, an erosion regime is considered to be critical at the opening and power delivery phases. The technique to enhance the magnetic insulation of the POS gap and to increase the switching voltage using externally applied magnetic field is discussed. Examples of use of the applied field for microsecond sub-MA POS to achieve switching voltages up to 3 MV are reported. Further development of POS schemes at megaampere currents is discussed. A design of the new six-section POS is proposed for the 3.7 MA facility prototyping the 1/24 of the future concept of the multimegajoule Baikal generator.