A feature which appears in an NMR spectrum of a molecule which should not be present based on the chemical structure and pulse sequence used.
The screening of an applied magnetic field experienced by a nucleus due to the electron cloud around an atom or molecule.
A variation in the resonance frequency of a nuclear spin due to the chemical environment around the nucleus. Chemical shift is reported in ppm. [Chapter 4]
One or more loops of a conductor used to create a magnetic field. In NMR, the term generally refers to the radiofrequency coil.
A mathematical operation between two functions.
Numerical data with a real and an imaginary component.
Continuous Wave (CW)
A form of spectroscopy in which a constant amplitude electromagnetic wave is applied.
A change in the axes used to represent some spatial quantity.
The condensation of air onto a surface cooled by a cryogenic liquid .
A magnetic field gradient used to dephase transverse magnetization.
A feature found on may newer spectrometers which eliminates wraparound artifacts by filtering out the higher frequency components in the time domain spectrum.
Doubly balanced mixer
An electrical device, often referred to as a product detector, which is used in NMR to convert signals from the laboratory frame of reference to the rotating frame of reference.
A form of magnetic resonance signal from the refocusing of transverse magnetization.
Echo Time ( TE )
The time between the 90 degree pulse and the maximum in the echo in a spin-echo sequence.
The interchange of chemically equivalent components on a molecule.
The interchange of spin state between two nuclei.
A magnetic field gradient coil shaped like the number eight.
Free induction decay ( FID )
A form of magnetic resonance signal from the decay of transverse magnetization.
Fourier transform ( FT )
A mathematical technique capable of converting a time domain signal to a frequency domain signal and vice versa.
Gradient ( G )
A variation in some quantity with respect to another. In the context of NMR, a magnetic field gradient is a variation in the magnetic field with respect to distance.
The ratio of the resonance frequency to the magnetic field strength for a given nucleus.
The component of a signal perpendicular to the real signal.
A specific set of RF pulses and magnetic field gradients used to produce an image.
Inversion Recovery Sequence
A pulse sequence producing signals which represent the longitudinal magnetization present after the application of a 180o inversion RF pulse.
Inversion Time (TI)
The time between the inversion pulse and the sampling pulse(s) in an inversion recovery sequence.
That image space represented by the time and phase raw data. The Fourier transform of k-space is the magnetic resonance image.
The resonance frequency of a spin in a magnetic field. The rate of precession of a spin packet in a magnetic field. The frequency which will cause a transition between the two spin energy levels of a nucleus.