15min:
CONTINUOUS-WAVE CAVITY RINGDOWN STUDY OF THE FIRST POSITIVE BAND SYSTEM OF N2*.

BRETT A. MCGUIRE, Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801; SUSANNA L. WIDICUS WEAVER, Departments of Chemistry and Astronomy, University of Illinois at Urbana-Champaign, Urbana, IL 61801; MICHAEL WICZER, Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801; BOGDAN NEGRU, Department of Chemistry, University of California, Berkeley, CA 94720; JOSHUA P. DIGANGI, Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706; BRIAN A. TOM, Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801; BENJAMIN J. MCCALL, Departments of Chemistry and Astronomy, University of Illinois at Urbana-Champaign, Urbana, IL 61801.

We previously reported the assignment of the N2+ A2 Pi u - X2 Sigma +g 2-1 vibronic band from continuous-wave cavity ringdown spectroscopy (cw-CRDS) of an N2 plasma. More than 400 lines from the N2* B3 Pi g-A3 Sigma u + system were also observed during this experiment. While assignments for 37 vibronic bands from the first positive band system of N2* have been reported in the literature, no assignments have been made within the frequency range of our laser. In this experiment, N2* was formed in a positive column discharge of a mixture of N2 and argon, and spectra were collected between 937 and 984 nm. We have now identified lines from the 3-3 band of N2*, and this spectral range is also expected to contain lines from the 2-2, 4-4, 7-8, and 8-9 bands. We will report on the progress of N2* line assignment and the molecular constants determined from this work.