The Determination of the Ground State and Electronic Structure of TaH Using Laser Excitation Spectroscopy and Dispersed Fluorescence

We have recorded several electronic transitions of gaseous tantalum hydride, originating from the ground electronic state as well as several low-lying excited states, at Doppler limited resolution in the visible region. The molecules were made in a hollow cathode discharge source by the reaction of sputtered tantalum with hydrogen gas in the presence of argon. The true ground state for this molecule was determined by a combination of resolved fluorescence and laser excitation analysis. The vibrational and rotational structure of the ground state and low-lying electronic states was also determined by this method. The high resolution of the laser excitation spectrum allowed the classification of several excited electronic states and the determination of their rotational constants