The nuclear magnetic moment of copper

Abstract

The doublet hyperfine structures of the resonance lines of the copper arc spectrum, λ3247 and λ3274, have been measured with a quartz Lummer plate. The lines are produced free from reversal effects, the doublet separations being respectively 379 and 405 × 10-3 cm-1. The following hyperfine structure interval factors are calculated: 3d104s2S½ = 197.5, 3d104p2P½ = 14 and 3d104p2P1½ = 4.8 (all in cm-1 × 10-3). The mean nuclear magnetic moment for the two copper isotopes, 63 and 65, is derived from the ground state, 3d104s2S½. The value found is μ = 2.47 nuclear magnetons, this being probably a better estimate than that given by other terms, since the ground state is spherically symmetrical and thus not affected by quadrupole moment of the nucleus. By adopting Schüler and Schmidt's value for the ratio of the magnetic moments of the two isotopes, it is found that μ (63Cu) = 2.43 and μ (65Cu) = 2.54 nuclear magnetons.