ELECTRON KINETICS IN A DISCHARGE PLASMA PRODUCED BY A FOCUSED MICROWAVE BEAM IN FREE-SPACE

A study is made of the electron kinetics in a discharge plasma produce d by a high-power beam of electromagnetic radiation in the centimeter- wave region under conditions approaching free space, when the dimensio ns of the chamber are much greater than the wavelength of the microwav e radiation. Two regimes of discharge production are investigated: the regime of short microsecond pulses at a repetition rate of 200 Hz, an d a single millisecond pulse regime. It is shown that at threshold val ues of the microwave energy flux density the electron density in the i nitial stages of discharge formation reaches the critical value, and t hat the average energy of the electrons is of the order of 1.5-3 eV. ( C) 1997 American Institute of Physics.