Spectroscopy of the E state of iodine monofluoride and rotational energy transfer of the B state in collisions with He, using two-photon sequential absorption spectroscopy
“The Two Photon Sequential Absorption (TPSA) technique has been used to investigate a state of 0+ symmetry of IF (iodine monofluoride) which has Te= 41292 cm-1, ωe = 248.8 cm-1, and Be = .1292 cm-1. This state has been designated the E state and dissociates to I+(3P2) and F-(1S0) ionic partners. The TPSA technique was also used to study collisions between IF molecules in specific rotational levels of the B state and He atoms. The total depopulation rate of an individual rotational level for vB = 6 of IF(B state) in He was found to be 4x10-10 cm3 molecule-1 s-1. In both experiments, individual rotational-vibrational levels in the B state were initially populated with pulsed dye laser radiation. A second pulsed dye laser was scanned through its dye profile, inducing transitions from the B state to the E state. In the initial investigation of the E state, the total cell pressure was maintained at 1 Torr and no collisionally populated B state levels were encountered. After the E state characteristics were determined, the cell pressure was increased to between 3 Torr and 9 Torr, and collisionally populated B state levels were observed”—Abstract, page ii.
Missouri University of Science and Technology
Networked Digital Library of Theses and Dissertations