Ionization-induced chirping and compression of a high-power microwave pulse. I. Experiments with a subnanosecond, 600-MW, 9.6-GHz microwave pulse propagating in a gas-filled waveguide
Phys. Rev. E 114, 045208 – Published 20 October, 2026
DOI: https://doi.org/10.1103/fvx4-3b4p
Abstract
We present results of experiments in which a subnanosecond high-power microwave pulse (-MW peak power, 9.6 GHz, <1 ns) traverses a neutral He-filled waveguide (<2.6 kPa) in the presence and absence of an axial external magnetic field. The pulse ionizes the gas along its track forming a temporally and spatially dependent plasma density within its time frame. This plasma, when it becomes sufficiently dense, affects the pulse so that it becomes positively chirped, with higher frequency at its tail than at its front. This chirped pulse exits the gas-filled region and while it propagates through the vacuum waveguide, it compresses due to the waveguide dispersion. The highest power of compressed pulses obtained is GW with a pulse width of ns. The results indicate that the presence of an axial magnetic field has a favorable influence on the level of compression. To the best of our knowledge, this is the first time ionization-induced chirping and compression is observed experimentally when a microwave pulse propagates in a neutral gas-filled waveguide.
