Eddy current heating of weakly conductive objects in high-performance gradient coils

Motivation: Conductive objects such as RF shield can pose heating risk due to eddy current in fast-switching gradient fields. Goal(s): To develop a systematic method to calculate eddy current heating when multiple gradient coils pulse simultaneously with independent waveforms. We explicitly consider interaction of different coils. Approach: Our method was tested against experimental measurement of temperature rise in a high-performance head-only gradient coil (MAGNUS) at 3T. Results: Predicted and measured local eddy current heating showed good qualitative agreement. Importance of coil coupling was demonstrated by the experimental data. Impact: We present a systematic method to calculate eddy-current heating induced by multiple independent field coils. The work permits accurate prediction of RF shield heating in high-performance gradient systems to ensure patient safety.