Catalysis in sealed CO2 lasers

Abstract

The degree of dissociation of CO2 in a sealed CO2-N2-He laser is limited by catalysis of reactions re-forming CO2, either by a platinum cathode or with outgassed hydrogen. The degree of dissociation measured in a laser is in quantitative agreement with that calculated for the reactions occurring in the discharge plasma if 5% of the hydrogen is in the atomic form. The hydrogen partial pressure is controllable by a palladium diffusion tube.

Radiation field induced perturbations in CO2laser plasmas. I. Current and pressure fluctuations

“…Thus for instance changes in the amplitude of dp/p might be expected as f approaches 200 Hz, but such a frequency is at the limit of performance of the micromanometer. However, in initially pure C02, which of course will be a CO2-CO-02 mixture because of CO2 dissociation in the electrical discharge (Smith and Browne 1974), ~0 0 1 -10 ms so dp/p should decrease over the modulation frequency range 20-100 Hz ( ~~5 0 -1 0 ms). Figure 3 shows the pressure fluctuation dp/p and the current fluctuation diji in 10 Torr of CO2 with a 10 mA discharge in the cell and with the incident beam intensity I= 11 W chopped with 7 varying from 2-100 ms. With this absorbing gas the current fluctuation was positive as expected and the pressure fluctuation as measured was positive, and thus assumed to be negative in the irradiated active volume (again as expected).…”

Spectroscopic Study of CO2 Decomposition in Sealed-off CO2 Lasers

“…The efficiency of the CO 2 regeneration can be enhanced by using a catalyst [23] and by the presence of impurities or gas-phase additives [e.g. 10,21,[23][24][25].…”

“…Several authors [e.g. 15,16,21,23] have found that the CO 2 equilibrium conversion into CO increases with decreasing pressure and increasing discharge current. A detailed theoretical study of different CO 2 laser mixtures by Cenian et al [17,22] made clear that the pressure dependence of the CO 2 conversion is linked to the pressure dependence of the reduced electrical field strength.…”

Study of the influence of the discharge tube material on the dc glow discharge in CO2 laser mixture

“…in [5,6]. The main goal of this work is to study a possible influence of the discharge tube material on the plasma composition.…”