Cavity-Enhanced Velocity Modulated Spectroscopy of TaO+

Abstract

Spectroscopy of heavy molecular ions such as TaO+ will reveal their energy level structure and critical molecular constants necessary for the design of future precision measurement experiments with potential to constrain physics beyond the standard model. My research uses cavity-enhanced velocity modulation spectroscopy (CEVMS) to obtain the spectra of molecular ions, wherein a laser is frequency stabilized to an optical cavity that surrounds a discharge tube. Initial application of CEVMS to study N2+ successfully measured the molecular ion’s spectrum and distinguished transitions of neutral and charged species. Next, tantalum (Ta) was placed on the electrodes into the discharge tube to sputter Ta into the discharge and form TaO+. However, data sets showed little to no presence of Ta nor TaO, thus a separate Tantalum cathode DC discharge was designed and added to the discharge tube. Ta was then confirmed in the discharge with a simple spectrometer, and preliminary CEVMS scans have shown promising data of documented Ta transitions. In conclusion, CEVMS has worked with N2+ and is a promising technique in the effort for spectroscopy of TaO+.