Patent ID: 8604793

Claim:
A method of shimming a superconducting magnet assembly that includes a cryostat and a superconducting magnet configured to be installed in the cryostat, said method comprising: while at room temperature injecting a current into coils of the superconducting magnet in order to generate a mapping field of the superconducting magnet; measuring the mapping field; determining, based on the mapping field, a plurality of room temperature field inhomogeneity characteristics of the superconducting magnet while the superconducting magnet is at room temperature and prior to the superconducting magnet being sealed in the cryostat; using the plurality of room-temperature field inhomogeneity characteristics in order to extrapolate with a processor what a plurality of normal-operating-state field inhomogeneity characteristics would be when the superconducting magnet is operating at normal operating temperature; and installing an initial set of passive shims inside the cryostat while the superconducting magnet is at room temperature, the initial set of passive shims being configured to compensate for the plurality of field inhomogeneity characteristics at a normal operating state when the superconducting magnet is operating at a normal operational temperature.