SUB-MILLIMETER WAVE SPECTROSCOPY OF NS RADICAL

Abstract

NS radical has been investigated since the early stage of microwave spectroscopy and radio astronomy. Anacona $et al^{a}$ observed the lines in the excited vibrational states of up to $v = 5$. Several years ago $Amano^{b}$ detected the lines as high as $v = 17$ in the 350 GHz region in a discharge reaction system of a mixture of $N_{2}(\sim 30$ mTorr) and $CS_{2}(\sim 1$ mTorr). More recently Lee $et al^{c}$ performed more accurate measurements up to 350 GHz region and obtained much improved molecular constants for the ground state. In this work, we extended the measurements to 680GHz and, by observing the higher-J transitions, the A-type doubling is resolved for the $^{2}II_{3/2}$ state. We combined all the available data to determine the best fit molecular constants for higher vibrational excited states. The vibrational dependence of the molecular constants, in particular, the A-doubling constants will be discussed.