Material that allows heat or electric current to flow.

Material that can serve both as a conductor and as an insulator of electricity.

A substance whose electrical resistance essentially disappears at temperatures near absolute zero. A perfect superconductor can carry an electrical current without losses. Nb, Tc, Pb, La, V, and Ta are superconductors at liquid helium temperature. A commonly used superconductor in MRI system magnets is niobium-titanium, embedded in a copper matrix to help protect the superconductor from quenching.

Electric currents induced in a conductor by a changing magnetic field or by motion of the conductor through a magnetic field.
One of the sources of concern about a potential hazard to subjects in very high magnetic fields or rapidly varying gradient or main magnetic fields. Can be a practical problem in the cryostat of superconducting magnets. Eddy currents can cause artifacts in images and may seriously degrade overall magnet performance. Common means to reduce the influence of eddy currents on gradient fields are eddy current compensation and shielded gradient coils (active or passive).

See also Eddy Current Compensation.

See also the related poll result: 'Most outages of your scanning system are caused by failure of'

(A or amp) The SI base unit of electric current.
Definition: Two parallel conductors, infinitely long and having negligible cross section, should be placed 1 meter apart in a perfect vacuum. One ampere is the current that creates between them a force of 0.2 micronewton per meter of length.
One ampere represents a current flow of 1 coulomb of charge per second.
One ampere of current results from a potential distribution of 1 volt per ohm of resistance, or from a power production rate of 1 watt per volt of potential.
The unit is known informally as the amp, but A is its official symbol and is named for the French physicist André-Marie Ampère.