Magnet structure and method of operation

A magnet comprising:

• a toroidal chamber having a toroidal axis,
• a plurality of substantially identical toroidal field coils on the toroidal chamber, in each of which coils can be established an electric current of substantially the same magnitude that flows in the same direction relative to the toroidal axis, and
• at least one electric conductor adjacent at least some of the toroidal field coils for carrying an electric current substantially equal in magnitude to the electric current that flows in a toroidal field coil, said current flowing in a direction so as to cancel out the effect of the current flowing in a portion of at least some of the toroidal field coils.

In a magnet having a toroidal chamber with a toroidal axis and a plurality of substantially identical magnetic coils on the toroidal chamber, a method of operating the magnet comprising the steps of:

• establishing in each coil an electric current of substantially the same magnitude that flows in the same direction relative to the toroidal axis, and
• establishing in at least one electric conductor adjacent the toroidal field coils an electric current substantially equal in magnitude to the electric current that flows in a toroidal field coil, said current flowing in a direction so as to cancel out the effect of the current flowing in a portion of at least some of the toroidal field coils while providing a current path between those toroidal field coil portions in which the current is canceled out.