Theoretical and experimental performance of a high‐power cw electron‐beam‐sustained electric laser

摘要

Computer‐code predictions of small signal gain, optical quality (medium refraction), and output power are presented for cw CO2 electric lasers. The fluid mechanics, plasma dynamics, and kinetic rate equations have been solved simultaneously for two cavity configurations: flow parallel and flow transverse to the electric field. We consider both recombination‐ and attachment‐dominated discharges. Experiments were carried out to test some of the theoretical predictions using an electron‐beam‐sustained electric‐discharge flowing carbon dioxide subsonic cw laser in which the gas flow is parallel to the electric field. Input power, electron density, electric field, and other experimental parameters were measured. Small signal gains and interferometric gas density measurements show a significant fraction of the input energy to be ’’hung up’’ in the vibrational excited states in agreement with theory. As a result, meaningful medium homogeneity (optical quality) measurements must be obtained under lasing conditions and cannot be extrapolated from zero‐flux results.