Laser Induced Fluorescence Spectroscopy of molecular bromine: Observations of Emission to High Vibrational Levels in the Ground (X) State

by Postell, David Jonathan

The Laser Induced Fluorescence spectrum of the B - X system of molecular bromine was recorded using a Red and Near Infrared sensitive PMT coupled to a scanning monochromator. A 543 nm HeNe laser was used to excite three resonances. Assignment of those resonances was made. A line narrowed Nd:YAG laser was used to excite eight fluorescence progressions, six from the (79,81) bromine isotopomer and one each from the (79,79) bromine and (81,81) bromine isotopomers. Analysis of the visible bands helped determine the resonances excited by the Nd:YAG laser. Fluorescence in the near infrared region, 9500 - 14000 angstroms, was recorded involving the v = 28 - 44 vibrational levels in the ground state. This data set, together with the data from previous work from Bernath and coworkers [J. Mol. Spectrosc. 200, 104-119 (2000)], was used to derive a set of Dunham coefficients to describe the ground state. In addition, an RKR curve was constructed for levels in the X state v = 0 - 44. Thus, we have extended observation to levels three quarters of the way to the dissociation limit.