Therapy tomograph with homogeneity device

US5545997A · kind A · utility

Assignee

• Bruker Analytische Messtechnik GmbH · DE

Inventors

• Michael Westphal · Boise, US
• Gunther Laukien · Rheinstetten, DE

Key dates

• Filing date: Jul 13, 1995
• Grant date: Aug 13, 1996
• Expiry date: Jul 13, 2015

Classification

• Technology area (CPC G): Physics
• CPC primary: G01R33/3806
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

In an NMR tomograph with superconducting main field coil (10) and large transverse access opening a compensation of inhomogeneities of the static magnetic field without hindering the axial and transverse access to the investigational volume (V) can be effected by the following elements: ferromagnetic homogeneity elements (20) which are arranged on the surface of the room temperature bore on both sides of the transverse access opening; at least one or more (a number p.gtoreq.1) superconducting correction coils (C.sub.1 and C.sub.p) which can be separately supplied with current and which are coaxial to the main field coil (10), whereby each correction coil (C.sub.1 through C.sub.p) comprises at least two partial coils (C.sub.1i, C.sub.1a through C.sub.pi, C.sub.pa), whereby all partial coils of all correction coils (C.sub.1 through C.sub.p) are cylindrical coils coaxial to a common axis (z) having a diameter less than the inner diameter (d.sub.a2) of the outer field coil (1a, 1b), whereby in each correction coil one partial coil (C.sub.1i through C.sub.pi) has, in each case, as small a separation from the middle plane (E) as possible generally equal to the separation of the radially …