Fine Structure of the He II Line λ = 4686 A.

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ACCORDING to the Dirac theory of the energy states in hydrogen-like spectra, levels of the same principal quantum number n which have the same value of the quantum number of total angular momentum j should coincide. Lamb and Retherford1 have shown that in the second quantum state of the hydrogen atom the 2 2S1/2-level lies 0·03 cm.-1 above the 2 2P1/2, term. Bethe2 has tried to explain this discrepancy by an interaction of the electron with the radiation field. His preliminary calculations show complete agreement with experiment for the hydrogen atom. For the He II spectrum he predicts a shift of the 3 2S1/2-level with respect to the 3 2P1/2-level by 0·13 cm.-1.

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  1. 1

    Lamb, jun., W. E., and Retherford, R. C., Phys. Rev., 72, 241 (1947).

  2. 2

    Bethe, H. A., Phys. Rev., 72, 339 (1947).

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KOPPERMANN, H., PAUL, W. Fine Structure of the He II Line λ = 4686 A.. Nature 162, 33 (1948) doi:10.1038/162033a0

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