The Value ofemfrom the Zeeman Effect

Abstract

The measurement of $\frac{e}{m}$ from the Zeeman effect of the red singlet lines of Cd and Zn has been repeated with careful attention to all of the sources of experimental uncertainty. The magnetic field has been measured, under the actual conditions of operation, with an uncertainty of about one part in three thousand. The final result is $\frac{e}{m}=1.7570\mathrm{}\pm \mathrm{0.0010.}$