fine structure

F0126200 (fīn)n.1. Physics The splitting of atomic spectral lines into closely spaced groups around a single wavelength, caused by the magnetic moments of orbiting electrons in the nuclei.2. Biology See ultrastructure.

fine structure

n (General Physics) the splitting of a spectral line into two or more closely spaced components as a result of interaction between the spin and orbital angular momenta of the atomic electrons. Compare hyperfine structure

fine′ struc′ture

(faɪn)

n. 1. a group of lines that are observed in the spectra of certain elements, as hydrogen. 2. the aggregate of components of the cytoskeleton. [1915–20]

Thesaurus

Noun

fine structure - the presence of groups of closely spaced spectrum lines observed in the atomic spectrum of certain elements; "the fine structure results from slightly different energy levels"spectrum line - an isolated component of a spectrum formed by radiation at a uniform frequencyatomic spectrum - (physics) a spectrum of radiation caused by electron transitions within an atom; the series of spectrum lines is characteristic of the element

Translations

struttura fine

Fine Structure

Fine structure (spectral lines)

The closely spaced groups of lines observed in the spectra of the lightest elements, notably hydrogen and helium. The components of any one such group are characterized by identical values of the principal quantum number n, but different values of the azimuthal quantum number l and the angular momentum quantum number j.

In atoms having several electrons, this fine structure becomes the multiplet structure resulting from spin-orbit coupling. This gives splittings of the terms and the spectral lines that are “fine’’ for the lightest elements but that are very large, of the order of an electronvolt, for the heavy elements.

Fine Structure

(or multiplet splitting), a splitting of the energy levels and spectral lines of atoms, molecules, and crystals that is caused by spin-orbit coupling. The number of sublevels into which an energy level is split depends on the number of possible spin orientations—that is, on the multiplicity K—and does not exceed K. In particular, for alkali-metal atoms the spin of the outer electron can have two orientations (K = 2); in this case, the energy levels are split into two sublevéis (doublet splitting), and the spectral lines are split into two closely spaced levels (doublets). For light atoms the magnitude of the fine-structure splitting of energy levels does not exceed 10^–4 electron volt; for spectral lines the corresponding magnitude is several wave number units (cm^–1). The splitting increases markedly as the nuclear charge Z becomes larger. The splitting of the energy levels of heavy atoms may reach several tenths of an electron volt.

M. A. EL’IASHEVICH

fine structure

[¦fīn ′strək·chər] (atomic physics) The splitting of spectral lines in atomic and molecular spectra caused by the spin angular momentum of the electrons and the coupling of the spin to the orbital angular momentum.

fine structure

fine structure

fine structure

fine′ struc′ture

Fine Structure

Fine structure (spectral lines)

Fine Structure

fine structure

fine structure

Words related to fine structure

noun the presence of groups of closely spaced spectrum lines observed in the atomic spectrum of certain elements

Related Words