Gradient coil design using Bi-2223 high temperature superconducting tape for magnetic resonance imaging.
Bi-2223 tape is a low-cost, long-length high temperature superconducting material. The new application of Bi-2223 tape for gradient coils for magnetic resonance imaging (MRI) is studied in this paper. Because Bi-2223 tape has a much higher critical current density and a much lower power loss than copper, a Bi-2223 high temperature superconductor (HTS) gradient coil shows great advantages in high gradient strengths, long continuous gradient rating, and free of cooling system over a copper gradient coil. The power losses of Bi-2223 tapes at working frequencies of gradient coils are compared to copper. The critical current degradation of tapes is also discussed. A prototype of HTS tape gradient coil is fabricated and its gradient field distributions are measured. Technical issues of resistance, gradient strength, continuous gradient rating, and cryostat are also discussed.
Yuan
Jing
J
MRI Lab, Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong.
Shen
G X
GX
D004553:Electric Conductivity; D004574:Electromagnetic Fields; D004867:Equipment Design; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D013696:Temperature