Study of a Calcium Afterglow in a Broida Oven

Abstract

A systematic study of a Broida source producing atomic calcium in ground state 1S and first metastable 1D and 3P states is presented. The relative concentration of the metastables, produced by a DC discharge, is monitored with carrier gas pressure, heating power and discharge current, and it is observed that low values of these parameters are favourable to 1D formation. These results are interpreted in terms of relative values of cross section of energy pooling forming the first resonant state 1P, and the ratio of these cross section is estimated to be σ(3P-3P)/σ(1D-1D) ≠5 ×10-4. Some properties of the source are described, including auto-absorptions of transitions originating from the 3P and collisional relaxation of reaction products of Ca with halogenated compounds. An example of utilization of the source for the study of metastable reactivity is presented

Reaction Cross Sections of Ca (41S, 43P and 31D States) With HalogenatedCompounds and Water

“…As we have V'r/V 1.09, from the values of (ro(CaC1)-1.77 A 239 (14) (16) (17) and (rp(CaC1)=.25A2, we can deduce from the measured slopes (7.2,10 -15 and 7.5,10-15 respectively) the relation (rD(A-X) + 100,(rp(A-X) 23.58 2 for the formation of CaBr A state. This result implies that these two cross sections are similar to those obtained for CaC1, with O-p(CaBr) slightly lower than (rp(CaC1), as its maximum value is .236 A2.…”

“…The absolute concentration of these species have been measured by a procedure which is shortly described below and their relative concentration could be varied by changing parameters (pression, temperature, discharge current) whose influence is described in ref. 17. The chemiluminescence spectra are taken with a monochromator Bausch & Lomb (0.6 rn focal length).…”