Ionization-Induced Self-Channeling of an Ultrahigh-Power Subnanosecond Microwave Beam in a Neutral Gas.

Ionization-induced self-channeling of a ≤500  MW, 9.6 GHz, <1  ns microwave beam injected into air at ∼4.5×10^{3}  Pa or He at ∼10^{3}  Pa is experimentally demonstrated for the first time.