Knowledge Bank

Rotational fine structure transitions have been observed for the $OH+$ and $OD+$ molecular ions V=O in the $X3\Sigma -$ ground state by far-infrared laser magnetic resonance spectroscopy. The ions were generated in an intracavity discharge using 1 torr of helium and 30 mT of $H2O/D2O$. Measurements of N=1+O, N=2+1 and N=3+2 have been made up to 17 kG for both species, with resolution of the $OH+$ hyperfine structures. The data is being analyzed using a modified Tinkham-Strandberg Hamiltonian for $\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}\Sigma$ states. Results of this analysis will be used to accurately predict astrophysically accessible rotational transitions. This work was supported by the Director, Office of Basic Research, U.S. Department of Energy.