hyperfine structure

(redirected from Hyperfine levels)
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hy·per·fine structure

 (hī′pər-fīn′)
n. Abbr. hfs
Any of the spectral lines formed from the splitting of broader spectral lines as a result of the interaction between the magnetic moments of electrons and atomic nuclei.

hyperfine structure

(ˈhaɪpəˌfaɪn)
n
(General Physics) the splitting of a spectral line of an atom or molecule into two or more closely spaced components as a result of interaction of the electrons with the magnetic moments of the nuclei. Compare fine structure See also Zeeman effect
References in periodicals archive ?
Since 1967, the SI second has been defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom.
This would have made the day 100 million years ago, some 23 and a half hours long when expressed in our current agreed duration of one second (9192631770 periods of the radiation corresponding to the transition between two hyperfine levels of the ground state of the cesium 133 atom).
And did you know that the second itself was defined, at the 1967 General Conference of Weights and Measures, as the duration of "9, 192, 631, 770 periods of the radiation corresponding to the transition between the two hyperfine levels of the fundamental state of the cesium 133 atom"?