The reaction of tungsten with CO2 and D2O at high temperatures and low pressures

The reactions of tungsten with CO2 and D2O at high temperatures and low pressures (T>2000 K, 10-5<P<10-2 Torr) has been studied using mass spectrometry. Under these conditions both reactants produce the same volatile oxide products which result in significant transport of tungsten compared to sublimation. The quasi-equilibrium model of gas surface reactions provides a good qualitative description of the rates of product formation. The fit is quantitatively satisfactory if the JANAF thermochemical values for the products are adjusted within their reported error. A comparison is made between these reactions and the reaction of oxygen with tungsten under similar conditions. (Auth.)