Measurement of the hyperfine structure Zeeman splitting of the ground state of the mercury ion

Abstract

The low field hyperfine structure Zeeman splitting of the mercury 199Hg+ ion has been observed in a dilute plasma by means of a multiple set spin exchange collision scheme. The experiment is performed in a resonance bulb in which the ions are produced by a direct current discharge in a side arm. The mercury ion resonance is observed by an indirect optical pumping scheme. Rubidium atoms are oriented by optical pumping with circularly polarized D1 rubidium resonance radiation. The rubidium atoms subsequently orient the mercury ions through spin exchange. A radiofrequency field is applied perpendicular to the orienting static magnetic field at the Zeeman frequency causing the mercury ion orientation to decrease. This loss of orientation is transferred by way of spin exchange back to the rubidium atoms causing a decrease in the intensity of pumping light transmitted by the bulb. The mercury ion resonance is found by sweeping the radiofrequency field through a range of frequencies and observing which frequency corresponds to the minimum transmitted light intensity. Magnetic resonance transitions were induced on 199Hg+ ions and the gJ factor has been determined and compared with the theoretical value obtained by including relativistic effects of the bound electron and configuration mixing. The measurement was made relative to rubidium.