A determination of the gyromagnetic ratio of the proton

Abstract

The gyromagnetic ratio of the proton has been measured by observing the precessional frequency of the protons of a sphere of water in a field of 1 to 2 milliwebers per square metre (10 to 20 gauss). The result, uncorrected for diamagnetism, is 2.675171 x 10 8 Wb -1 m 2 s -1 (26751.71 c.g.s.e.m.) referred to the unit of electric current maintained at the N.P.L. by standard resistances and standard cells. This figure is 1.1 part in 10 6 less than the comparable result of the National Bureau of Standards. The 50% or ‘probable’ systematic error is estimated to be 2 in 10 6 and the interquartile range of the 40 observations is 3 in 10 6 .