How magnetic is helium-3? | Max-Planck-Gesellschaft https://www.mpg.de/18784452/news-from-mpi
For the first time, the electronic and nuclear g-factors of the 3He+ ion were measured directly with a relative precision of 10–10. The electron-nucleus magnetic interaction was measured with an accuracy improved by two orders of magnitude. The g-factor of the bare 3He nucleus was determined via an accurate calculation of the electronic shielding. The results constitute the first direct calibration for 3He nuclear magnetic resonance (NMR) probes.
, PTB Center for Time, Constants, and Fundamental Symmetries