Knowledge Bank

The $K=0\to 1$ absorption doublet of $CO+$ has been detected in a glow discharge in carbon monoxide or helium-carbon monoxide. The measured frequencies are 117 692.55 MHz for $J=1/2\to 1/2$ and 118 101.99 MHz for $J=l/2\to 3/2$. The original observation used source modulation, an unlocked klystron, and a discharge tube which was cooled to near liquid nitrogen temperature. More recently, we have detected the signal with field spinning Zeeman modulation, a phase locked klystron, and a discharge tube at room temperature. Measurements of the low field Zeeman splittings are consistent with theory to within experimental error.