Propagation of high power microwave pulses in the air

The dynamic behavior of the propagation of high-power microwave pulses depends on the intensity, frequency, and width of the pulse and the physical processes occurring during the interaction of the pulse with the air. An attempt has been made experimentally to single out these processes. The experiment was conducted in a large Plexiglas chamber filled with dry air at various pressures. A microwave pulse was fed into the cube by an S-band microwave horn placed at one side of the chamber. A second S-band horn placed at the opposite side of the chamber was used to receive the transmitted pulse. The microwave power was generated by a magnetron tube driven by a soft tube modulator. The magnetron produces a 1-MW peak output power at 3.2 GHz. The Paschen breakdown condition was determined. Two mechanisms responsible for two different degrees of tail erosion were identified. A self-consistent theoretical model is being developed to describe the experimental results.