Knowledge Bank

Optical Microwave Double Resonance (OMDR) experiments were performed on the $BO2$ radical in the gas phase. Single mode argon ion laser radiation at 5145 {\AA} and high power microwaves with 2-3 GHz frequency were used producing double resonance signals from the radical. The laser excites the R(7) rotational line of the (110) $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\Sigma g+\leftarrow (010)2\Sigma \mu -$ vibronic transition from the $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\Pi \mu$ ground state to the $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\Pi g$ excited state. The microwave transitions responsible for the double resonance signals are magnetic dipole transitions among the Zeeman sublevels of the J = 7 1/2 level of the ground state. Two microwave transitions, $(Mj\prime =-4 1/2)\leftarrow (Mj\prime \prime =-51/2)$ and $(Mj\prime =-31/2)\leftarrow (Mj\prime \prime =-41/2)$ are identified. Thorough investigation of the Renner effect was carried out.