Patent ID: 6369464
Filing Date: 2002-04-09
Classification: G01R

Abstract:
An actively shielded superconducting magnet arrangement for the generation of a magnetic field in the direction of a z axis in a working volume disposed about z=0, the arrangement comprising:a first radially inner coil system (C1) carrying a first current and having a first dipole moment; a second radially outer coil system (C2 resp. C2â€²) disposed coaxially about said first coil and carrying a current approximately equal to said first current, said second coil system having a second dipole moment approximately equal but opposite in direction to said first dipole moment, wherein at least parts of said second coil system (C2 resp. C2â€²) are electrically connected in series with said first coil system (C1); a first superconducting switch (S1) to short-circuit a first current path of the magnet arrangement comprising at least said first radially inner coil system, said first path being superconducting during operation; and a second superconducting switch (S2) to short circuit a section (A2 resp. A2â€²) of said second coil system (C2 resp. C2â€²) thus forming a second current path in such a way that each winding of said second coil system is part of at least one of said first and second current path, wherein said second current path is superconducting during operation and is substantially inductively decoupled from said first current path, said section being disposed symmetrically with respect to z=0.