Expected Magnetic Field Quality From the Preliminary Measurements Performed During the Manufacturing of the Iseult/Inumac Whole-Body 11.7-T MRI Magnet

A new innovative whole-body 11.7-T MRI magnet is currently being manufactured at Alstom Belfort as part of the Iseult/Inumac project. The magnet will be installed by the end of the year in a neuroscience research center with other very high-field MRI equipment operating in France at CEA Saclay since November 2006. This actively shielded magnet system, which was manufactured from a NbTi superconductor, will generate a homogeneous magnetic field of 11.75 T within a 90-cm warm bore. This paper presents the geometrical controls performed on the Iseult/Inumac magnet during the different fabrication stages, and it compares them to the specifications. A FEM analysis taking into account magnet cooling down and energizing has also been performed, in order to estimate the final magnet homogeneity, taking into account load tests and geometrical measurement performed on the main coil. Measured field maps will be analyzed and compared to the field computation based on geometrical measurements.