Knowledge Bank

Using interferometric spectra obtained on the McMath Solar Telescope FTS spectrometer in double pass configuration ($0.0025cm-1$ resolution), improved rotation-vibration molecular parameters of acetylene in the $\nu 5$ region were determined as compared to Refs, (1). The frequency analysis of one and two quantum hotbands involved the states of $\nu 5,2\nu 5,\nu 4+\nu 5,3\nu 5,2\nu 4+\nu 5,$ and $\nu 4+2\nu 5$. The least square fit was based on the numerical diagonalization of the hamiltonian using the Hellman-Feynman theorem which permits the calculation of the effective dipole moment (2,3). FTS data as well as tunable diode laser spectra recorded at the University of Tennessee clearly indicate the dominant. $\ell$-resonance effect upon the hotband intensities; experimental intensities agree well with the predicted values.