10min:
DISCHARGE MODULATION TECHNIQUE FOR DETECTION OF TRANSIENT SPECIES PRODUCED IN PULSED SUPERSONIC JET BY COLOR CENTER LASER SPECTROSCOPY.

M. ISHIGURO, T. IMAJO, K. HARADA, K. TANAKA AND T. TANAKA, Department of Chemistry, Faculty of Science, Kyushu University 33, Hakozaki, Higashi-ku, Fukuoka 812-81, Japan.

A discharge modulation technique has been applied to color center laser spectroscopy for the detection of radical species generated in a pulsed supersonic jet . Transitions in the nu3 band of the CH3 radical rotationally cooled to 23 K were recorded by the phase sensitive detection technique with an improved signal to noise ratio. The sensitivity attained corresponds to 6× 10-5 absorption.