Precision Measurements in the Zeeman Effect

Calibration of a solenoid producing magnetic fields up to 7300 gauss has been carried out and a value of K, the field-current ratio determined. This value is K = 36.835 ± .011 gauss/ampere. Fields produced by four measured single layer standard solenoids were used as comparison standards. K was measured both at low currents and at the operating current used for spectroscopic measurements. A small decrease occurs in the value of K as the current increases. Expansion of the solenoid as it is heated by the passing current is largely responsible for this decrease. Values of e/m have been obtained from the Zeeman separations produced in this magnetic field. Singlet lines of Cd λ6439, of Zn λ6362, of Ne λ5852 and λ6074, and of He λ5015 and λ4921 were used. The Zn and Cd lines required a careful theoretical examination of the g-values of the exciting levels. Ne required an application of the g-sum rule. No correction of g was required for He. Lines were excited in the positive column of a discharge. Liquid air cooling was applied to the He source. Zeeman patterns were photographed with a Fabry* Perot interferometer with the following results: Cd λ6439: e/m = 1.7570 ± .0007 Zn λ6362: e/m = 1.7570 ± .0008 Ne λ5852 and λ6074: e/m = 1.7580 ± .0014 He λ5015 and λ4921: e/m = 1.7560 ± .0009 These results are stated as e/m = (1.7570 ± .0007) x 107 abs. e.m.u. per gram.