New Classifications in the Spectra of Au I and Au II

Abstract

Measurements have been made on the spectrum of gold excited in a hollow cathode discharge in helium. In the region investigated (600A-10,000A) some 2000 new gold lines were found, of which 237 have been newly classified in the gold arc spectrum and 83 have been newly classified in the first spark spectrum of gold. The new classifications involve 32 new terms in Au I and 12 new terms in Au II. In the arc spectrum, the $\mathrm{ns}$ and $\mathrm{nd}$ series have been extended to $n=14\mathrm{}$, and new values of the $5f^{2}F$ levels are suggested. The series limit, $5d^{10}{}_{}{}^1{}_{}{}^{}S_0^{}{}_{}{}^{}$ of Au II, is calculated to be 74,410 ${\mathrm{cm}}^1$ above the ground state, $5d^{10}6s{}_{}{}^2{}_{}{}^{}S_{\frac{1}{2}}^{}{}_{}{}^{}$, of Au I. Several new terms above the series limit have been located. In the first spark spectrum of gold, the resonance triplet discovered by Sawyer and Thomson has been confirmed. The lowest six members of the $5d^{9}7p$ group have been found, and the $5d^{8}6s^2$ configuration has been completed.