magnetic field gradient

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mag·net·ic field gra·di·ent

in magnetic resonance imaging, a magnetic field that varies with location, superimposed on the uniform field of the magnet, to alter the resonant frequency of nuclei and allow calculation of their spatial position.
Synonym(s): field gradient
References in periodicals archive ?
Consequently, we achieved a maximum accelerating electric field gradient of 41 MV/m (performance required for ILCs: at least 35 MV/m).
Gravity field gradient along a levelling profile has a significant effect on the levelling results.
Axial gradient of the magnetic field gradient (dB/dL) at the wall of the channel, which caused oxygen transfer towards the pellet surface was equal to 1.
From the earlier equation for magnetization, the magnetic attractive force acting on a particle is the product of the particle magnetization and the magnetic field gradient and can be expressed as:
For the ESR experiments, cylindrical samples with diameters of [approximately equal to]7 mm were cut from the plaques at selected time intervals, trimmed to fit the 5-mm diameter of the ESR sample tube, and placed in the ESR resonator with the symmetry axis along the long (vertical) axis of the resonator, parallel to the direction of the magnetic field gradient.
The recording head for perpendicular recording consists of a single pole inductive write head with a suitable flux return path designed for high efficiency, low stray field sensitivity and sharp field gradient capable of writing on perpendicular media with coercivities in excess of 5000 Oe.
The magnets make a loud, metal-on-metal clanging as they generate the strong field gradient needed to image the brain, and there's also a deep, mechanical throb that some subjects describe as pulsing in rhythm with their heartbeats.
In fact, this is a steep metamorphic field gradient, indicating that all the samples experienced temperatures in excess of 800[degrees]C both during and shortly after peak metamorphism over a range of depths (ca.
8 mol/L) was needed and the water signal was suppressed by a field gradient.
Too much current and the field gradient may be strong enough, even in flawless areas, to attract and hold particles over the entire casting surface, masking flaw indications.