Knowledge Bank

Using the technique of velocity modulated laser absorption spectroscopy and a color center laser, the $\nu 1$ fundamental band of $HCO+$has been measured. This method involves modulating the drift velocity of the ion in an AC discharge ($-$2.5 KHz) and detecting the Doppler shifted absorptions with lock-in techniques. $HCO+$ was detected with a $H2/CO$ ratio of 10/1 and a total pressure of $\sim$1 torr. A least squares fit of the 25 lines that were observed yielded values for $\nu 0(3088.727cm-1)$, and for $B\prime$, $D\prime \prime$, $B\prime$, and $D\prime$ that are in excellent agreement with results from microwave spectroscopy. $\mathrm{<mrow\; data-mjx-texclass="ORD">\ast </mrow>}$Supported by NSF Grant # CHE8207307