anomalous Zeeman effect اُسکر ِ زیمن ِ ناسان oskar-e Zeeman-e nâsân
*Fr.: effet Zeeman anormal*
The splitting of a spectral line into several components
in the → *Zeeman effect* when the magnetic field is weak.
The splitting is much more complex than in the normal effect. The number of
components of the lines often considerably exceeds their number in the normal effect.
Contrarily to the normal Zeeman effect, the anomalous effect
cannot be explained by classical theory. The historically "anomalous" effect is
accounted for by the inclusion of electron spin in the total angular moment.
In fact the idea of electron spin was put forward (Uhlenbeck and Goudsmit, 1926)
to explain the anomalous Zeeman effect. → * anomalous*; → *Zeeman effect*. |

inverse Zeeman effect اُسکر ِ زیمن ِ وارون oskar-e Zeeman-e vârun
*Fr.: effet Zeeman inverse*
The → *Zeeman effect* obtained in absorption.
The phenomenon is observed by sending white light through an absorbing
vapor when the latter is subjected to a uniform magnetic field.
The laws governing the inverse effect are similar to those for the
direct effect. → *inverse*; → *Zeeman effect*. |

longitudinal Zeeman effect اُسکر ِ زیمن ِ درژنایی oskar-e Zeeman-e derežnâyi
*Fr.: effet Zeeman longitudinal*
The → *Zeeman effect* when the emitting source is
viewed in the direction of the magnetic field.
In the normal longitudinal effect, each spectral line
is split into two components with frequencies ν ± Δν.
The line with the frequency ν - Δν shows left-hand
→ *circular polarization* and that with frequency
ν + Δν shows right-hand circular polarization.
→ *transverse Zeeman effect*. → *longitudinal*; → *Zeeman effect*. |

transverse Zeeman effect اُسکر ِ زیمن ِ تراگذر oskar-e Zeeman-e tarâgozar
*Fr.: effet Zeeman transverse*
The → *Zeeman effect* when observed at right angles
to the orientation of the magnetic field. Un un-displaced line is observed along with
a doublet, three lines in all, with the frequencies ν and
ν ± Δν. The two displaced components correspond to a plane
of → *polarization* parallel to the external magnetic
field and the un-displaced line to a plane of polarization perpendicular to this field.
→ *longitudinal Zeeman effect*. → *transverse*; → *Zeeman effect*. |

Zeeman effect اُسکر ِ زیمن oskar-e Zeeman
*Fr.: effet Zeeman*
The splitting of spectral lines into closely-spaced components when
the radiating substance is placed in a strong → *magnetic field*.
Distinction is made between the *normal* and
→ * anomalous Zeeman effect*s, and also the
longitudinal and transverse Zeeman effects. In the normal
→ *longitudinal Zeeman effect* each spectral line
is split into two components with frequencies ν ± Δν.
In the normal → *transverse Zeeman effect*
un un-displaced line is observed along with a doublet, i.e. three lines in all,
with the frequencies ν and ν ±Δν. In the classical theory
of the normal Zeeman effect, the motion of an electron in an atom is regarded as
the harmonic oscillation of a linear harmonic oscillator. Arbitrary linearly polarized
oscillation of the electron can be resolved into two oscillations: one along
the magnetic field and the other in a plane perpendicular to this field. The latter
can be further resolved into two oscillations, circularly polarized with opposite
directions of rotation that occur in the Larmor precession frequency. Classical theory
cannot explain the anomalous Zeeman effect. Both effects are accounted for in
quantum mechanics as the result of changes in the energy levels of atomic
electrons due to the interaction of their
→ *orbital angular momentum* and
→ *spin angular momentum* with each other
and with the external magnetic field.
See also → *inverse Zeeman effect*. Named after Pieter Zeeman (1865-1943), Dutch physicist who discovered the phenomenon;
→ *effect*. |