Magnetic Moment of the Proton in H2O in Units of the Bohr Magneton

  • William D. Phillips
  • William E. Cooke
  • Daniel Kleppner


We have made a new measurement of the magnetic moment of protons in a spherical sample of water in units of the Bohr magneton. This ratio, μP′B,is needed in many atomic physics experiments for converting into atomic units the value of a magnetic field measured as an NMR frequency. It is used in the determination of α from 2e/h experiments and in the evaluation of other constants such as γp and mp/me. Also, by comparing μp′B to μpB, the free proton moment in Bohr magnetons(1), one obtains the absolute value of the diamagnetic shielding factor for protons in water. Shielding factors of different molecules can be intercompared to very high precision, so that the present result permits absolute determination of the shielding factor for any molecule.


Audio Signal Microwave Absorption Bohr Magneton Spherical Sample Thermal Control System 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    P. F. Winkler, D. Kleppner, T. Myint and F. G. Walther, Phys. Rev. A5, 83 (1972).ADSCrossRefGoogle Scholar
  2. 2.
    H. Hellwig, R. F. C. Vessot, M. W. Lecine, P. W. Zitzewitz, D. W. Allen and J. W. Glaze, I. E.E.E. Trans. I.strum. Meas. 19, 200 (1970).Google Scholar
  3. 3.
    The coating material was supplied by Prof. Stuart B. Crampton of Williams College.Google Scholar
  4. 4.
    Such corrections will generally not be of concern to the experimenter who uses NMR to measure magnetic fields, since most of the errors arise from the necessity in our case of using interchangeable sample holders.Google Scholar
  5. 5.
    H. Grotch and R. A. Hegstrom, Phys. Rev. A4, 59 (1971).Google Scholar
  6. 6.
    E. R. Cohen and B. N. Taylor, J. Phys. Chem. Ref. Data 2, 4 (1973).CrossRefGoogle Scholar
  7. 7.
    E. B. D. Lambe, Ph.D. Thesis, Princeton University 1959 (unpublished).Google Scholar
  8. 8.
    J. C. Hindman, J. Chem. Phys. 44, 4582 (1966). See also Schneider et al. J. Chem. Phys 28, 601 (1958) and Jacobson, B.S. Thesis, M.I.T. 1972 (unpublished).Google Scholar
  9. 9.
    E. B. D. Lambe (private communication).Google Scholar

Copyright information

© Springer Science+Business Media New York 1976

Authors and Affiliations

  • William D. Phillips
    • 1
  • William E. Cooke
    • 1
  • Daniel Kleppner
    • 1
  1. 1.Res. Lab. of Elec. and Department of PhysicsM.I.T.CambridgeUSA

Personalised recommendations