Knowledge Bank

By means of high resolution laser polarization spectroscopy of the C-X $system1$ a new excited state in the cesium dimer, the `D' - state was observed. Dye laser excitation within this $D1\Sigma +u\leftarrow X1\Sigma +g$ system yields extended fluorescence progressions ranging from $\nu ""=0$ up to $\nu ""=140$. The analysis of the fluorescence spectra and the application of the Leroy-Bernstein method to the determination of the dissociation limit results in a dissociation energy of $De=3648\pm 5cm-1$, which is two orders of magnitude more accurate than previously known.