Numerical analysis of eddy current problems involving z gradient coils in superconducting MRI magnets

摘要

The pulsive field of z gradient coils induces eddy currents in the cryostat walls of MRI (magnetic resonance imaging) superconducting magnets. These eddy currents are computed here by a network method and the effects of the eddy currents are investigated while varying the resistivity of the cryogenic radiation shield. Two paired z gradient coils are proposed to improve the efficiency and linearity of the z field gradient.