THE EMISSION SPECTRUM OF $Ar_{2}$ IN THE VUV-REGION

Y. Tanaka and K. Yoshino. J. Chem. Phys. 53, 2012 (1970).Author Institution:The emission spectrum of the argon dimer has been studied in the VUV region. Liquid nitrogen cooled argon was excited with a rf (Tesla coil) discharge. A 6.65-m McPherson vacuum spectrograph equipped with a platinum-coated 2400 lines/mm ruled grating is used and provides a reciprocal dispersion of 0.3 {\AA}/mm in the second order. Only the band system $I^{(1)}$ appeared with discrete structure. The rotational analysis of the bands indicates that the coupling scheme in the lowest excited state is closer to Hund-Mulliken case b than to case c, so that the excited symmetry may be assigned approximately as $^{3}\Sigma^{+}_{u}$ rather than $1_{u}, O^{-}_{u}$. An attempt has been made to use spectroscopic results to depict the shapes and positions of the long-range portions of the first two excited states ($^{3}\Sigma^{+}_{u}$ and $^{1}\Sigma^{+}_{u}$) of $Ar_{2}$ relative to each other and to the ground state $X^{1}\Sigma^{+}_{g}$