Abstract
Negative ions are computed to be formed on a time scale and in quantities such that they may be a cause of plasma instability observed in low pressure electrical discharge convection CO2 lasers. In a typical CO2−N2−He−H2O laser mixture the principal ions are CO −3 , CO −4 and H− with the total negative ion densityn − given by 0.1n e <n −<n e , wheren e is the electron density: but if the gases are re-cycled or if there is an air leak NO −2 and NO −3 are formed in significant amounts andn − can become greater thann e in a time considerably less than the gas dwell time in the electrical excitation discharge. CO is effective in reducingn − in a system without re-cycling, but is ineffective in a re-cycled system with the oxides of nitrogen present.
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A. L. S. Smith: unpublished
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Shields, H., Smith, A.L.S. Negative ion effects in CO2 convection laser discharges. Appl. Phys. 16, 111–118 (1978). https://doi.org/10.1007/BF00931431
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DOI: https://doi.org/10.1007/BF00931431