SUBMILLIMETER LASER STARK SPECTROSCOPY OF METHYL FLUORIDE AT $311 \mu m$

$^{1}$L.H. Johnston, R.P. Srivastava, and R.M. Lees, J. Mol. Spectrosc. 84, 1-40 (1980). $^{2}$G. Graner, Molecular Physics 31, 1833-43 (1976).The Stark Effect in $CH_{3}F$ has been studied using the 964.313 G.Hz laser line. The spectra were taken for both s and o polarizations and up to 65,000 v/cm. The experimental technique used is similar to (I). The spectra are consistent with a linear field relationship. We identify the multiplet transitions as $J_{K} = 19_{K}\leftarrow 18_{K}$ in the ground vibrational state. We have seen seven families with K=10, 11, 12, 13, 14, 15 and 16, K values of the families were identified by relative Stark speeds and intensities. Zero field frequencies are given for all families taking into account the rotational dependence of Dipole moment, polarizability and II order Stark Effects. The results obtained here are more accurate than those calculated from Graner's Molecular Constants (2)