COLLISION BROADENING OF CO2 TRANSITIONS IN THE REGION OF 4.3-MU-M - EFFECTS OF BROADENING GAS (HE, AR AND N-2), ROVIBRATIONAL STATES AND TEMPERATURE

The collision-broadening parameters, b(L)(0) for a number of lines in the Delta v(3), = 1 transitions from the (00(0)0), (01(1)0), (02(0)0) and (02(2)0) vibrational states of (CO2)-C-12-O-16 and the (00(0)0) state of (OCO)-O-18-C-12-O-16 have been measured at room temperature (300 K) and with N-2, Ar and He as the broadening gases, using a tunable IR diode laser. The values of b(L)(0) decrease with increase in the rotational quantum numbers associated with the transition but there is no significant difference in the broadening of lines from different vibrational bands. Measurements of b(L)(0), were also carried out at 160 K on lines in the (00(0)1,00(0)0) band. With the changes in b(L)(0) (units of cm(-1) atm(-1)) expressed in the form b(L)(0)(T) = b(L)(0)(T = 298 K) (298/T)(n), n = 0.69 +/- 0.17 for He, 0.88 +/- 0.18 for Ar, and 0.85 +/- 0.09 for N-2.