LASERSPECTROSCOPY OF THE $A \leftarrow X$ TRANSITION OF LiAr
Loading...
Date
1994
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Ohio State University
Abstract
Li-Ar molecules have been produced in a supersonic beam by expanding a mixture of Ar gas and Li vapor through a nozzle into a vacuum. A temperature of about $800^{\circ} C$ is required in the stagnation area in order to get a sufficient amount of Li atoms in the gas phase. The high-resolution absorption spectrum of the $A^{2} \Pi \leftarrow X^{2} \Sigma$ transition of LiAr has been measured between 14720 and 14895 $cm^{-1}$ by scanning a cw dye laser and by observing the laser-induced fluorescence light. Rovibrational quantum numbers could successfully be assigned to about 750 molecular absorption lines of the isotopomer $^{7}$LiAr and to about 120 lines of $^{6}$LiAr. The parameters of molecular rotation, of spin-orbit interaction and of $\lambda$-type doubling have, up to now, been obtained for vibrational levels $v^{\prime\prime} = 0\ldots 2$ of $X \Sigma$ and for $v^{\prime} = 5\ldots 8$ of $A \Pi$. The molecular spin-orbit interaction of the $A\Pi$ state is about 10 times larger than the spin-orbit splitting of the $2 \ ^{2}P$ state of the Li atom. Preliminary values of equilibrium distance and well-depth are: 4.87(1) {\AA}, $41(2) cm^{-1}$ for $X\Sigma$ and 2.49(5) {\AA}, $900 (80) cm^{-1}$ for $A\Pi$.
Description
Author Institution: Institut f\""{u}r Strahlungs-und Kernphysik, Technische Universit\""{a}t Berlin