Patent ID: 7772949
Filing Date: 2010-08-10
Classification: G01R

Abstract:
1. A method for making a magnet structure for Nuclear Magnetic Resonance imaging apparatus, which magnet structure has at least two opposing magnetic pole pieces, which are located at a certain distance from each other and delimit an imaging region, which pole pieces are formed by at least one massive layer of a magnetically permeable material, and at least one layer of magnetically permeable material comprising a pack of superimposed sheets or foils, electrically insulated from each other, each of which sheets has an upper face and a rear face with respect to the massive layer and each of which sheets has cuts arranged over the surface of the sheet in positions that are at least partly non coincident with the cuts of at least one, or both adjacent sheets, wherein the cuts are formed on each sheet with such a pattern of cuts that the cuts of an overlying sheet or foil are disposed in offset and not coincident positions with respect to the cuts of the underlying sheet, when said overlying sheet is laid over the preceding sheet in a reversed position, i.e., with the front face overturned against the preceding sheet, the pack of sheets being formed by the alternate disposition of said sheets in a normal position, with the upper face turned toward the massive layer and the sheets in the overturned position.