Nuclear Spin of Rubidium-86

Abstract

THE nuclear spin I of rubidium-86 has been measured by the atomic beam method using magnetic resonance; a mass spectrometer was employed to select the correct isotope1. A pronounced resonance was obtained at a frequency of 2.36 Mc./sec. in a magnetic field of 4.22 gauss, which gives I = 2. This value is in agreement with the observed shape of the β-spectrum2. The hyperfine structure separation was found to be 3,900 ± 100 Mc./sec., which means a magnetic moment of 1.66 ± 0.4 nuclear magnetons. The results suggest that the magnetic moment is probably negative and it would then have a value of − 1.68 ± 0.01 nuclear magnetons. It is planned to extend the measurements to obtain a more accurate value of the magnetic moment and definitely establish its sign.