Bruker Switzerland Ag

Bruker Biospin Ag

Kenneth J Guenter

Robert Schauwecker

Joerg Hinderer

Patrik Vonlanthen

Stephen Alfred March

Thomas Wuethrich

Alexander Baer

Frank Borgnolutti

A method for charging a superconductor bulk magnet includes: step a) charging the magnet charger system so as to generate a first magnetic field in the sample volume, the superconductor bulk magnet having a temperature T>T(); step b) cooling the superconductor bulk magnet to a temperature T<T(); step c) discharging the magnet charger system, which inductively charges the superconductor bulk magnet, such that the superconductor bulk magnet traps a second magnetic field in the sample volume (). In step a), the field adjustment unit is set such that the first magnetic field generated by the magnet charger system in the sample volume includes a homogeneous magnetic field component and at least one non-homogeneous magnetic field component (). The non-homogeneous field component is chosen so that the second magnetic field of step c) has a higher homogeneity than the first magnetic field of step a) in the sample volume.

Method for charging a superconductor bulk magnet by field-cooling, with at least one non-homogeneous magnetic field component of the applied charger magnetic field

In a magnet system: &#x2014;a superconducting main field magnet () generates a magnetic field in a first sample volume (), &#x2014;a superconducting additional field magnet () generates another field in a second sample volume (), &#x2014;a cryostat () has a cooled main coil container (), an evacuated RT (room temperature) covering (), and an RT bore () which extends through the main and the additional field magnets, and &#x2014;a cooled additional coil container () in a vacuum. The RT covering has a flange connection () with an opening () through which the RT bore extends, a front end of the additional coil container protrudes through the opening into the RT covering such that the additional field magnet also protrudes through the opening into the RT covering, and a closure structure () seals the RT covering between the flange connection and the RT bore.

Magnet system for performing 2-field NMR experiments and associated retrofitting method

A method for charging an HTS shim device in a cryostat having a room temperature bore using a charging device. A shim switch temporarily interrupts the superconducting state in a section of an HTS shim conductor path. The charging device includes a primary circuit with a normal-conducting charging coil and the conductor path forms a secondary circuit. A current change in the secondary circuit results from a change in magnetic flux generated by the charging coil through the secondary circuit. In a first phase the shim switch is opened to interrupt the superconducting state in a section of the conductor path, the charging coil is positioned in the bore, and the current in the primary circuit is changed; in a second phase, the conductor path is superconductingly closed; in a third phase, the current in the primary circuit is changed and/or the charging coil is removed from the bore.

Method for charging an HTS shim device and magnet arrangement

A shim device having an HTS shim conductor track (C) and a shim switch (Sw) The track (C) is curved around an axis (z) and the shim switch is arranged in a first conductor track portion (S), to interrupt its superconducting state. The track (C) extends around at least a first opening (O) and a second opening (O) such that the track (C) has a first circumferential current path (L), a second circumferential current path (L) and a third circumferential current path (L). Two of the three paths (L, L, L) each surround only one of the two openings and one of the three paths (L, L, L) surrounds both openings. The first portion (S) is part of only the first path (L) and the second path (L). This produces a persistent HTS shim for field homogenization, allowing both a complex field distribution and a large degree of design freedom.

Shim device, magnet assembly, and method for charging a shim device

A magnet assembly in a magnetic resonance apparatus includes a cryostat and a superconducting main field magnet coil system arranged therein for generating a magnetic field in the direction of a z-axis in a working volume. The magnet assembly includes a shim device arranged inside the cryostat for adjusting the spatial variation or homogeneity of the magnetic field generated in the working volume by the magnet coil system. The shim device comprises at least one closed superconducting shim conductor path having an HTS layer. The HTS layer forms a surface that is geometrically developable such that unwrapping onto a plane changes the geodesic distance between any two points on the surface formed by the HTS layer by no more than 10%. The inner and/or outer contour of the geometrical development of the HTS layer describes a non-convex curve.

Magnet assembly comprising closed superconducting HTS shims

A layer wound magnet coil includes a central coil region and end coil regions adjoining the central coil region along an axial line of symmetry. The central coil region includes layers of coil windings of an anisotropic material. The end coil regions include layers of coil windings of the anisotropic superconducting material interspersed with layers of non-superconducting material.

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Zurich, Switzerland

Kenneth J Guenter