Patent ID: 6157279
Filing Date: 2000-12-05
Classification: G01R

Abstract:
An open magnet comprising:a) a first assembly including:(1) a longitudinally-extending first axis;(2) at least one annular main coil coaxially aligned with said first axis and carrying a first main electric current in a first direction;(3) at least one annular shielding coil coaxially aligned with said first axis, disposed longitudinally outward from said at least one main coil of said first assembly, and carrying a first shielding electric current in a direction opposite to said first direction;(4) at least one magnetizable member positioned between coaxially aligned with, and proximate to said at least one main and shielding coils of said first assembly to decouple said at least one main and shielding coils; and(5) at least one magnetizable pole piece generally coaxially aligned with said first axis and spaced apart from said at least one magnetizable member of said first assembly;b) a second assembly longitudinally spaced apart from said first assembly and including:(1) a generally longitudinally-extending second axis generally coaxially aligned with said first axis;(2) at least one main coil generally coaxially aligned with said second axis and carrying a second main electric current in said first direction;(3) at least one shielding coil generally coaxially aligned with said second axis, disposed longitudinally outward from said at least one main coil of second assembly, and carrying a second shielding electric current in said opposite direction;(4) at least one magnetizable member positioned between, coaxially aligned with, and proximate said at least one main and shielding coils of said second assembly; and(5) at least one magnetizable pole piece generally coaxially aligned with said second axis and spaced apart from said at least one magnetizable member of said second assembly; andc) at least one nonmagnetizable support member abuttingly connecting said at least one magnetizable pole piece of said first assembly and said at least one magnetizable pole piece of said second assembly.