Table of Contents
Laser Chemistry
Volume 12, Issue 1-2, Pages 123-136

Reaction Dynamics of Electronically Excited Calcium Atom

1Departamento de Química Física, Facultad de Ciencias Químicas, Universidad Complutense, Madrid 28040, Spain
2Unidadde Haces Moleculares y Láseres, Centro de Estudios Avanzados Complutense, C/Isaac Peral, s/n, Universidad Complutense, Madrid 28040, Spain
3Laboratoire de Photophysique Moleculaire, Université de Paris-Sud, Bât. 213. Campus d'Orsay, Orsay Cedex 91405, France
4Universidad de Castilla la Mancha, Ciudad Real, Spain
5Université de Rennes I, France

Received 1 October 1991; Accepted 15 October 1991

Copyright © 1992 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Absolute values of the total chemiluminescence cross-section for the beam-gas Ca(3P, 1D) + Cl4C → CaCl(A, B) + Cl3C and Ca(3P, 1D) + SF6 → CaF(A, B) + SF5 reactions have been measured at low collision energy, ET = 0.15 and 0.14eV, respectively. Both metastable atomic calcium states Ca(3P, 1D) were produced under low voltage dc-discharge conditions. By changing the discharge conditions, different metastable concentrations were produced to measure the state-to-state cross-section for both 3P and 1D reactions. The following values for the total chemiluminescence cross-sections were obtained:

σD1 = 1.77 Å and σP3 = 0.25 Å for the Ca(3P, 1D) + Cl4C → CaCl(A, B) + Cl3C reaction.

σD1 = 0.59 Å2 and σP3 = 0.56 Å2 for the Ca(3P, 1D) + SF6 → CaF(A) + SF5 reaction.

σD1 = 0.04 Å2 and σP3 = 0.12 Å for the Ca(3P, 1D) + SF6 → CaF(B) + SF5 reaction.

In addition, beam-beam experiments were carried out at the same average low collision energy that of the beam-gas, and therefore, normalization between both experiments was possible. This procedure allowed us to obtain the excitation function of the Ca(1D) + SF6 reaction in absolute values over the 0.15–0.60eV collision energy range.

On the other hand, by simulation, the ratio of CaCl(B-X/A-X) emissions intensities was found to be of 0.15. The variation of this ratio with the relative concentration of 1D/3P in a Broida oven leads to the conclusion that this state favours the formation of the B state in the chemiluminescent Ca(3P, 1D) + CH3CHCl2 → CaCl(A, B) + CH3CHCl reaction.