Analysis of Field Uniformity of MRI Magnet

Magnetic resonance imaging (MRI) is the largest application of superconductivity. Field uniformity is important requirement to MRI magnet. Method of polynomial expansion is used in calculation of magnetic field of MRI magnet. Strategically arrangements of unshielded and shielded multiple coils are deduced on base of eliminating low order coefficients of coils. Shifts of coils along axial direction are taken into account to show influences of manufacture errors on field uniformity.