Knowledge Bank

The flow tube and burner used to generate a chemiluminescent flame of lead oxide (PbO) have been redesigned in order to enhance the emission from the flame. A 0.5 m Jarrel-Ash monochromator was used with an RCA 7265 photomultiplier tube to resolve the emission. Flame temperature as measured with a thermocouple was $175\circ C$. On the basis of a mass balance the upper limit of the number density of lead atoms was calculated to be $2\times 1014$ atoms/cc for a crucible temperature of $890\circ C$. Lead oxide spectra were observed over the range 400-750nm. The resolution for intense spectral regions was 2.5 \AA. Emissions were observed for the band systems $D-X,B-X,A-X,b-X$, and $a-X$. A linear least squares program was written to calculate the spectroscopic constants for each of the states. The program which used a weighted average over all data was based on a procedure initially developed by Albritton and co-$workers(1)$. Potential energy curves were prepared for some of the energy states with a program developed by C. Vidal and co-$workers(2)$ which utilized the RKR and inverted perturbation approach (IPA). Results for PbO will be presented discussed. $\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}$D. L . Albritton, A. L. Schmeltekopf, and R.N. Zare, J. Mol, Spectrosc. 67, 132 (1977). $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$C. R. Vidal and H. Scheingraber, J. Mol, Spectrosc, 65, 46 (1977).