The Magnetic Moment of the Proton

The molecular beam magnetic resonance method has been employed to measure, in the same magnetic field, the frequency corresponding to a reorientation of the proton in the molecule NaOH and the frequency corresponding to a transition between certain of the h.f.s. levels of the ground state of both the atoms Cs¹³³ and In¹¹⁵. From these data are calculated the ratio of the g factor of the proton, gH, to the g factor of total electronic angular momentum, gJ, with the result gHgJ(Cs,²S1/2)=15.1911×10^-4 and gHgJ(In,²P1/2)=45.6877×10^-4. From a knowledge of the ratios gJ(Cs¹³³)gJ(Na²³) and gJ(In¹¹⁵)gJ(Na²³) two entirely independent values of the ratio gHgJ(Na²³) have been obtained: From indium gHgJ(Na)=15.1923×10^-4.From caesium gHgJ(Na)=15.1931×10^-4.From the known value of gₛgₗ=2(1.100116), where gₛ and gₗ are, respectively, the g factors of electron spin and of orbital angular momentum, and on the basis of the assumptions that gₛ=gJ and that gₗ=1, we find, gH=30.4206×10^-4±0.005percent.Including a small diamagnetic correction, the magnetic moment of the proton, μH, is μH=(15.2106×10^-4±0.005percent) Bohr magneton.