Economical generation regime of a supersonic continuous-wave chemical DF laser

We have performed experimental and computer-aided theoretical studies of the effect of the dilution degree psi(2) of a secondary fuel (deuterium) by an inert gas (helium) on the output characteristics of a supersonic cw chemical DF laser with a flat nuzzle array, constructed in accordance with the nozzle-nozzle reagent mixing scheme. It is shown that an increase in the dilution degree in the range of 0 <= psi(2) <= 20 leads to a monotonous increase in the lasing zone length (a decrease in the radiation load on the resonator mirrors) and a drop in the laser specific energy output. With an increase in the optical path length (a decrease in the threshold gain), the sensitivity of the laser energy characteristics to the dilution degree decreases. Consequently, for a high-power DF laser (with a long nozzle array) with partial replacement of expensive deuterium with cheaper helium, a potential possibility for the implementation of an economical generation regime with acceptable specific energy output is achieved. The conditions for the implementation of this regime are identified.