Study of a Calcium Afterglow in a Broida Oven

A systematic study of a Broida source producing atomic calcium in ground state $^1$S and first metastable $^1$D and $^3$P 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 $^1$D formation. These results are interpreted in terms of relative values of cross section of energy pooling forming the first resonant state $^1$P, and the ratio of these cross section is estimated to be $\sigma(^3{\rm P}-^3{\rm P})/\sigma(^1{\rm D}-^1{\rm D}) \ne 5 \times 10^{-4}$. Some properties of the source are described, including auto-absorptions of transitions originating from the $^3$P 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