radius below the cut-off value for the fundamental circular waveguide mode (TE 11). The
discharge tube is surrounded with a multicusp magnetic field constructed with permanent
magnets which provide a minimum-B configuration. Short pulse (0.05-1.0 µs) microwaves of
3 GHz and 60-100 kW peak power with a repetition frequency of 10-500 Hz are launched
into the narrow tube with the propagation vector perpendicular to the cusped magnetic field …