Isotopic mass dependence in the bound–free D–X fluorescence spectrum of Br2

Abstract

The D → X transition is studied for both natural Br2 and 81Br2, using 1576-Å radiation from an F2 laser to excite the fluorescence. The characteristic interference structure at the long-wavelength end of the spectrum is found to be much more sensitive to changes in isotopic mass than to changes in the vibrational and rotational quantum numbers, when all three represent comparable changes in the energy of the excited state. These dependences are consistent with predictions from semiclassical theory.