Superconducting gradient shield coils
US5289128A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 27, 1992 |
| Grant date | Feb 22, 1994 |
| Priority date | — |
| Expiry date | Mar 27, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/4215
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An examination region (12) is defined within the bore of a superconducting magnet assembly (10). An RF coil (22) and gradient magnetic field coils (14) are disposed within the bore of the superconducting magnet assembly around the examination region. The superconducting magnet includes a hollow, cylindrical vacuum vessel (40). An annular, liquid helium holding low temperature reservoir (60) extends centrally through the vacuum vessel, but is sealed therefrom such that liquid helium is not drawn into the vacuum. A plurality of annular superconducting magnets (56) are received in the low temperature reservoir immersed in the liquid helium. A first cold shield (44) and a second cold shield (50) are mounted in the vacuum vessel surrounding the low temperature reservoir. A main magnetic field shield coil (66) is disposed in the low temperature reservoir outside of the annular superconducting magnets for canceling the magnetic field generated by the annular magnets surrounding the magnet. A gradient shield coil (70) is mounted in low temperature reservoir inside the annular superconducting magnets to cancel magnetic fields generated by the gradient magnetic field coils in the region beyo…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.