Improvement of MRI magnet design through sensitivity analysis

Superconducting magnets for MRI are designed to provide high level of magnetic flux density in a wide testing volume with the greatest level of field homogeneity. The design of such magnets is usually performed using optimization techniques able to tune the geometrical parameters of the magnets, taking also into account constructional issues and dimensions and packaging factors of the wires for each coil and, in addition, technical and physical constraints, such as the critical current of the superconductor to prevent the quench phenomenon. Unfortunately due to manufacturing tolerances, the actual geometrical parameters of the magnet differ from the design ones, affecting the field homogeneity. In this paper the effects of the manufacturing tolerances on the field homogeneity are investigated for an MRI magnet by means of a statistical Monte Carlo analysis.