nuclear magnetic resonance

[noo-klee-er mag-net-ik rez-uh-nuhns, nyoo-]

noun

Physics.

1. the selective absorption of electromagnetic radiation by an atomic nucleus in the presence of a strong, static, magnetic field: used in research and in medicine to monitor tissue metabolism and to distinguish between normal and abnormal cells. NMR

nuclear magnetic resonance

noun

1. NMR. a technique for determining the magnetic moments of nuclei by subjecting a substance to high-frequency radiation and a large magnetic field. The technique is used as a method of determining structure See also electron spin resonance

nuclear magnetic resonance

1. The absorption of electromagnetic energy (typically radio waves) by the nuclei of atoms placed in a strong magnetic field. The nuclei of different atoms absorb unique frequencies of radiation depending on their environment, thus by observing which frequencies are absorbed by a sample placed in a strong magnetic field (and later emitted again, when the magnetic field is removed), it is possible to learn much about the sample's makeup and structure. Nuclear magnetic resonance has no known side effects on the human body, and is therefore used to analyze soft body tissues in magnetic resonance imaging (MRI).

Pronunciation Note

See nuclear ( def. ).

Word History and Origins

Origin of nuclear magnetic resonance¹

First recorded in 1940–45