On the analysis of the first spark spectrum of sulphur

Abstract

The spark spectrum of sulphur was measured quite thoroughly by Eder and Yalenta in the region λ 3028⋅32 to λ 5819⋅54 in the year 1904; they gave wave-lengths up to the third place of decimals. In 1907, Sir Norman Lockyer showed that some of the stronger lines of S + occur in the spectrum of Rigel (β-Orionis, class B8), but not in the spectra of either α-Cygni (Giant Ao) or Sirius (Dwarf Ao). After this time, no experimental or theoretical work seems to have been undertaken to elucidate the structure of this spectrum. In 1924, Millikan and Bowen published their data on the vacuum spark spectrum of sulphur within the region λ 370⋅2 to X λ 1259⋅3, but the wave-lengths do not seem to have been very accurately given. A first glance at the published data showed that lines of S, S + , S ++ and possibly also of higher stages have been all mixed up in these data. Hence an attempt was first made to locate certain groups. Taking the structure diagram as given by Saha, the possible transitions can be graphically located as follows:— 2K . 8L M 1 M 2 → M 3 3 ↓ N 1 → N 2 → N 3 ↓ ↓ O 2 → O 1 ↓ P 1 P 2 . O 3 The lines 3M 2 ↙2M 2 M 3 ↖ 2M 2 N 1 lie in the Schumann region. An attempt to identify these lines with Millikan and Bowen’s data yielded no satisfactory result. The next groups of lines are from transitions, 2M 2 N 1 ↖ 2M 2 N 2 . 2M 2 M 3 ↙