Knowledge Bank

The fluorescence of $Cs2$ was observed inside a heat pipe oven which was operated at $sim350\circ C$. The spectra were recorded at high resolution $(0.005cm-1)$ with a Fourier transform Interferometer. The fluorescence excited by the $Ar+$ and $Kr+$ lasers was observed mainly in the $4300cm-1,6500cm-1,8500cm-1$ spectral regions and also near the laser lines. The molecular constants of the pumped $E\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}\Pi u+$ state where deduced from an analysis of the rotational relaxations and also thanks to the great number of pumped rotational levels. Molecular constants for three gerade states: $(1)\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}\Pi g,(2)\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}\Sigma g+$ and $(3)\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}\Sigma g+$ were derived from the study of the fluorescence spectra [1]. When using the ring dye laser, very high vibrational levels of the (2) $\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}\Sigma g+$ state were observed. Triplets in the $4200cm-1$ region were assigned to the fluorescence from the $D\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}\Sigma u+$ state to the $1g$ component of the lowest $\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}\Sigma g+$ state.