A coil of wire, or solenoid, consists of a wire coiled up into a spiral shape. When an electric current flows, the shape of the magnetic field is very similar to the field of a bar magnet.

A coil of wire, or solenoid, consists of a wire coiled up into a spiral shape. When an electric current flows, the shape of the magnetic field is very similar to the field of a bar magnet.

Faraday also observed that it was more efficient if the coil was wound around a metal core, as this helped to concentrate the magnetic field.

Such joining technology, if established, would bring the creation of efficient, high magnetic-field coil and long-distance, direct-power transmission close to realization - qualities that are expected ...

In a stellarator, the electric currents passing through the coils create a magnetic field organized into nested magnetic surfaces in the shape of a deformed doughnut. This magnetic field confines ...