TEMPERATURE-DEPENDENCE OF COLLISION BROADENING AND SHIFT IN THE NO A[-X (0,0) BAND IN THE PRESENCE OF ARGON AND NITROGEN

A rapid-tuning intracavity-doubled cw dye laser was used to resolve absorption lineshapes in the NO A <-- X (0,0) band at 226 nm. Lineshapes acquired both in room-temperature cells and in a shock tube were fit to Voigt profiles to measure the collision broadening and shift for various colliders. The room-temperature (295 K) broadening coefficients were determined to be 0. 503 cm-1atm-1 for argon broadener and 0.583 cm-1atm-1 for nitrogen broadener. The corresponding room-temperature (295 K) shift coefficients were found to be -0.159 and -0.180 cm-1atm-1, respectively. No dependence on rotational quantum number was observed for either width or shift. The room-temperature self-broadening and shift coefficients were found to be 0.551 and -0.171 cm-1atm-1, based on measurements on a single J" line. By performing shock-tube measurements to 2800 K, the temperature exponents for the broadening and shift coefficients were determined to be -0.65 and -0.58 for argon collider and -0.75 and -0.56 for nitrogen collider, respectively. In all profiles, evidence of collision-induced lineshape asymmetries were observed.