Abstract #1800

MRI Magnet Coils Stray Capacitance Effects & the Circuit Analysis Method

Yihe Hua¹, Anbo Wu¹, Chao Yang², Yan Zhao¹, Ye Bai², Fengshun Tan², Shike Huang²

¹Global Research Center, GE, Shanghai, China, People's Republic of; ²GE Healthcare, China, People's Republic of

The MRI magnet composed of a set of multi-layer solenoidal coils provides the main magnetic field for MRI imaging. Due to the large number of turns in each main coil, its overall parasitic capacitor is possibly at a few nF level. Together with their large inductance, the coils may have a resonance frequency in KHz range, which is within the gradient pulse signal bandwidth. Circuit analysis method considering parasitic capacitance effects has been developed for different types of superconducting magnets to examine the voltage induced at main coil terminals, dielectric loss in main coils and the impact to the input impedance of gradient coils.