Patent ID: 6215383
Filing Date: 2001-04-10
Classification: G01R

Abstract:
A magnet with magnetic shielding comprising:a) a longitudinally-extending axis;b) at least one main coil positioned around said axis and carrying an electric current in a first direction;c) at least one magnetizable correction ring positioned around said axis longitudinally spaced apart from said at least one main coil and not carrying an electric current;d) at least one shielding coil positioned around said axis, disposed radially outward from said at least one main coil and magnetizable article, and carrying an electric current in said opposite direction to said first direction; ande) at least two magnetizable annular members which are not carrying an electric current, which are positioned around said axis and are longitudinally spaced apart from each other, which are disposed radially outward from said at least one main coil and magnetizable article, and which are disposed radially inward from said at least one shielding coil.