Magnet model

A computational simulation of the field generated by a magnet.

Magnetic circuit

A way of thinking about magnetic systems, similar to an electric circuit. Allows predicting, for example, the flux density in the various parts of a permanent magnet system.

Magnetometer

An instrument to measure magnetic flux density (B) or magnetic field intensity (H).

Magnitude

The magnetic field is a vector quantity. We may be interested in its individual components or its total magnitude.

Mapping

The process of measuring magnetic field intensity at many different points, in order to understand the structure of the field within a volume. For example, in MRI one typically maps the field by measuring many points on a sphere containing the imaging region.

Modulation

In a continuous-wave NMR teslameter, the Larmor frequency has to be crossed and re-crossed to perform a measurement. This is achieved by modulating either the frequency of the RF field or the magnetic field.

Monitor

See Control.

Moving coil

A fluxmeter approach to measure the field at a point, by moving a coil from the point of interest to an area of zero field.

Moving wire

A fluxmeter approach to mapping very narrow-gap magnets, by measuring the voltage changes in a wire swept through the gap. 

MRI

Magnetic Resonance Imaging. Using NMR to image the interior of a solid body, usually for a medical diagnosis.

Multipole magnet

In the accelerator world, multipole is a term used to refer to N-pole magnets, usually quadrupole, sextupole, octupole, or higher order.

Multiplexer

An adaptor that allows multiple probes to be connected to a single magnetometer.