Translationally and rotationally resolved excitation of CO2(0002) by collisions with hot hydrogen atoms

摘要

Time domain tunable diode laser absorption spectroscopy has been used to measure rotationally resolved transient absorption line shapes and nascent rotational populations for CO2molecules excited into the (0002) vibrational state by collisions with translationally hot hydrogen atoms. The 0002 rotational population distribution and rotationally resolved linewidths are remarkably similar to those previously obtained for 0001. Within the context of a simple physical model used to interpret the data, the similar rotational distributions and translational recoils for 0001 and 0002 suggest that these two states are excited by similar collision trajectories, wherein asymmetric stretching excitation is optimized when H strikes near the end of the Ondash;Cndash;O molecule. The magnitude of population scattered into 0002 is sim;21 times smaller than that scattered into 0001.