Diode laser probing of CO2 and CO vibrational excitation produced by collisions with high energy electrons from 193 nm excimer laser photolysis of iodine

Time domain diode laser absorption spectroscopy has been used to measure vibrational, rotational, and translational excitation of CO2 and CO following excimer laser photolysis of iodine in a low pressure mixture of CO2 and I2 or CO and I2. Nascent rotational population distributions have been measured in a number of low-lying CO2 vibrational levels, including 0001, 1000, 0200, 0220, and 0002 as well as the v=1 level of CO. In addition, measurements of CO2 translational excitation have been obtained for the majority of the rovibrational states probed. Significant vibrational excitation of CO2 has been observed with almost no increase in rotational and translational energy of the molecule. These results are consistent with the production of vibrationally excited CO2 via collisions with hot electrons which arise from multiphoton ionization of I2. Direct detection of the electrons has been accomplished using a time-resolved magnetic induction technique