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Intensity Ratios of the Hyperfine Structure Components of the Resonance Lines of Potassium


IN view of conflicting evidence as to the sign of the nuclear spin of potassium 39, it was decided to make a quantitative investigation of the intensities of the hyperfine structure components of the resonance lines. The method used was similar to that used by the authors for the hyperfine structure of the resonance lines of silver1. The absorption produced by an atomic beam of potassium in the resonance lines given by a potassium lamp similar to that previously described was observed by means of an etalon of 5 cm. plate separation, with heavily silvered plates. Under these conditions, the adjacent orders of the emitted lines are well separated from each other, and the hyperfine structure can be observed as a narrow absorption doublet. In order to measure intensities, a photograph is made first of the emitted light without absorption, and then with absorption ; the rednctions in the logarithmic intensities by the absorption lines give their respective absorption coefficients, and the ratio of these the required intensity ratio.

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JACKSON, D., KUHN, H. Intensity Ratios of the Hyperfine Structure Components of the Resonance Lines of Potassium. Nature 140, 276–277 (1937).

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