nuclear magnetic resonance (redirected from Field cycling)

nuclear magnetic resonance: see magnetic resonance.

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nuclear magnetic resonance (NMR)

Selective absorption of very high-frequency radio waves by certain atomic nuclei subjected to a strong stationary magnetic field. Nuclei that have at least one unpaired proton or neutron act like tiny magnets. When a strong magnetic field acts on such nuclei, it sets them into precession. When the natural frequency of the precessing nuclear magnets corresponds to the frequency of a weak external radio wave striking the material, energy is absorbed by the nuclei at a frequency called the resonant frequency. NMR is used to study the molecular structure of various solids and liquids. Magnetic resonance imaging, or MRI, is a version of NMR used in medicine to view soft tissues of the human body in a hazard-free, noninvasive way.

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nuclear magnetic resonance [′nü·klē·ər mag′ned·ik ′rez·ən·əns]

(physics)

A phenomenon exhibited by a large number of atomic nuclei, in which nuclei in a static magnetic field absorb energy from a radio-frequency field at certain characteristic frequencies. Abbreviated NMR. Also known as magnetic nuclear resonance.