Shockhyphen;Tube Study of the Radiative Processes in Systems Containing Atomic Oxygen and Carbon Monoxide at High Temperature

摘要

Absolute intensity measurements of the radiation emitted in systems containing atomic oxygen and carbon monoxide were made by shock heating gas mixtures containing O2, O3, CO, CO2, and Ar to pressures between 0.5 and 1.5 atm and to temperatures of 2679deg;plusmn;16deg;K and 2943deg;plusmn;26deg;K. The emission intensity was recorded as a function of time simultaneously in selected spectral intervals in the wavelength range between 2500 and 8000 Aring;. The absolute spectral intensity distribution for the radiative combination of O and CO was derived. Contributions to the measured emission intensity at wavelengths below 4500 Aring; by the radiative combination of oxygen atoms and by the radiation resulting from the electronic excitation of O2were evaluated; at wavelengths greater than 7000 Aring; an unexpected rise in the emission intensity was found. The absolute spectral emission intensity for the Osngbnd;CO combination was proportional to the concentration product, (O)(CO), at all wavelengths employed and at 2943deg;K, a rate constant of 3.80times;105cm3moleminus;1middot;secminus;1for the overhyphen;all radiative combination, O+COrarr;CO2+hvwas calculated for the wavelength interval 2500 to 7200 Aring;. The activation energy for the radiative combination of O and CO was found to be 2.5plusmn;0.6 kcal moleminus;1by combining the present results with lowhyphen;temperature, dischargehyphen;flowhyphen;tube data over the common spectral interval between 3200 and 5000 Aring;; also, an activation energy of 31plusmn;12 kcal moleminus;1was determined for the energyhyphen;transfer process CO2*+O2rarr;CO2+O2*, where the starred quantities represent electronically excited molecules.