Measurements ofgFactors by a Beam-Foil Quantum-Beat Technique

The Landé $g$ factors for some excited levels in ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ar}$ ii and iii are measured by a beam-foil spectroscopic quantum-beat technique. The values are obtained from ratios of $g$ factors, which are made with a standard $g$ value taken as known. Where comparison is possible, the results of the measurements are generally in agreement with previous Zeeman measurements. In cases where discrepancies are found, the sources of the disagreement are discussed and identified. The technique may be applied to other elements having excited states with lifetimes in the nanosecond range. Other types of $g$-factor measurements for such states are not easily applicable.