Maxwell coil

A Maxwell coil is a device for producing a large volume of almost constant (or constant-gradient) magnetic field.

It is named in honour of the Scottish physicist James Clerk Maxwell.

Though Maxwell did not specifically state that current for the coils came from the same source, his work was specifically describing the construction of a sensitive galvanometer designed to detect a single current source.

[3] This produces a uniform-gradient magnetic field near the centre of the two coils.

Maxwell describes the use of the 2-coil configuration for the generation of a uniform force on a small test coil.