Propagation of long, high-power microwave pulses through the air

The passage of long, high-power microwave pulses in the atmosphere was studied using a one-dimensional computer code. The objective of this study was to obtain a time history of the electron conductivity and peak density, as well as the peak plasma density. The results are summarized as follows: (1) the threshold level depends on pulse frequency and length; (2) electron avalanche occurs only when the pulse intensity exceeds the threshold level for air break-down, and this results in tail erosion; (3) for higher pulse intensities, it requires less time to initiate electron avalanche, which results in transmitting smaller portions of the pulse; (4) the general characteristics of the electron density, conductivity, and plasma frequency are quite similar for both cases; and (5) as the pulse amplitude rises, the electron conductivity and density and the plasma frequency also rise.