1^st International Laser M2P Conference

J. Phys. Colloques 48 (1987) C7-673-C7-675
DOI: 10.1051/jphyscol:19877163

LASER-INDUCED FLUORESCENCE FROM C ²&Pi TO X ²Σ⁺ AND H' ²Ɗ STATES OF BaF ANALYSED BY FOURIER TRANSFORM SPECTROSCOPY

C. EFFANTIN¹, J. d'INCAN¹, A. BERNARD¹, G. FABRE², R. STRINGAT¹, J. VERGÈS³ and R. F. BARROW<sup>4

1</sup>  Laboratoire de Spectrométrie Ionique et Moléculaire, CNRS UA-171 et Celphyra), Université Lyon-I, 43 Bd du 11 Novembre 1918, F-69622 Villeurbanne Cedex, France
²  Laboratoire d'Optique Atomique et Moléculaire, Faculté des Sciences et des Techniques, Parc Valrose, F-06034 Nice Cedex, France
³  Laboratoire Aimé Cotton, CNRS II, Bât. 505, F-91405 Orsay Cedex, France
⁴  Physical Chemistry Laboratory, Oxford University, South Parks Road, GB-Oxford OX1 342, Great-Britain

Abstract
The C²&Pi state of BaF has been excited by lines of an argon-ion laser. BaF molecules were produced in a heat-pipe in which barium was heated to 1000°C m the presence of argon at a pressure of 1 Torr, fluorine appearing as an impurety. The induced emission was studied m the ranges 8500 to 9500 and 19 400 to 20 300 cm^-1. The spectra were recorded on a Fourier transform spectrometer at a resolution of about 0.027 cm^-1. In these conditions we observe in emission the C ²&Pi → X ²Σ⁺ system in the visible region, and also fluorescence in the infra-red, which is assigned to C²&Pi → H' ²C. This ²Ɗ state is the third member, now found for the first time, of the d-complex whose other components are A ²&Pi and B ²Σ⁺. Until a more rational scheme is introduced, the new state will be labelled H' : the analogous state in BaH is labelled H, but this letter has already been used for a high-lying state in BaF.