HIGH-RESOLUTION LASER SPECTROSCOPY OF $A^3 \Pi_{g}^{+}$ SYSTEM OF $I_{2}$

$^{1}$. D.R.T. Appadoo, R.J. LeRoy, P.F. Bernath, S. Gerstenkorn, P. Lu***, J. Verg\`{e}s, J. Sinzelle, J. Chevillard, and Y.D*** Aignaux, J. Chem. Phys., 104, 903 (1996). $^{2}$. T. Yukiya, N. Nishimiya, and M. Suzuki, J. Mol. Spectrosc., 182, 271 (1996). $^{3}$. S. Gerstenkorn and P. Luc. J. Phys., 46, 867 (1985).Author Institution: Dept. of Electronic Engineering, Tokyo Institute of PolytechnicsThe molecular constants for the A-state of $I_{2}$ calculated by the NDE method have been reported by D.R.T. Appadoo $et al.^{1}$ Yukiya et al. measured the Q-branch lines up to $v^{\prime} = 45$ using a titanium sapphire ring laser, where the hyperfine components were partially resolved at the higher vibrational bands than those of $v^{\prime} = 35$, and determined the spectroscopic $constants.^{2}$ In this work we report the line splittings of the P and R-branches caused by the nuclear quadrupole coupling effect. The 23 bands of $(v^{\prime} = 15 -19)\leftarrow (v^{\prime \prime}= 3), (v^{\prime}= 18 -30) \leftarrow (v^{\prime \prime}= 4),$ and $(v^{\prime} = 25 -29) \leftarrow (v^{\prime \prime} = 5)$ were newly assigned. The unperturbed line positions were obtained using the high J approximation. The spectroscopic constants of $T_{v}, B_{uf}, D_{v}, H_{v}$ and $q_{v}$ of the A-state determined by the aid of the Dunham parameters of the $X-state^{3}$ will be presented