Magnet and cryostat arrangement, and method for passive shimming

Abstract

An arrangement for setting the spatial profile of a magnetic field in a working volume of a main field magnet (2), in particular a superconducting main field magnet, of a magnetic resonance installation. The main field magnet is arranged in a cryostat (1) and the spatial profile is set by a passive shim apparatus (3) with magnetic field forming elements which are arranged within the cryostat during operation and which have cryogenic temperatures. The magnetic resonance installation contains a room temperature tube (4), in which the sample volume is situated during operation. The passive shim apparatus is introduced into or removed from the cold region of the cryostat via a vacuum lock (5), without needing to ventilate the cold region of the cryostat. This provides a relatively simple, cost effective, and time-efficient method to carry out a stable field homogenization using a passive shim apparatus.

Dependencies are inferred from the claim text.