Magnetic Design of a Half-Size 5 T High-Temperature Superconducting Coil for MRI

We have been developing a liquid-helium-free magnet using High-Temperature Superconducting (HTS) wire for MRI. The aim of this research and development is to commercialize a 3-T HTS magnet for whole body MRI which has the characteristics of being liquid-helium-free, small, and light-weight. HTS coil requires tolerance of a high magnetic field, 7 T, and it must have high current density, 200 A/mm
²
, for developing a small and light weight magnet used for 3-T MRI. A half-size 5-T HTS magnet will be manufactured in order to demonstrate the tolerance of high magnetic field and high current density of the coil, which are equivalent to a whole-body 3-T MRI magnet in a half-size HTS magnet. In this paper, we have investigated the arrangement of coils of a half-size 5-T coil. The designed coil consists of 124 double-pancake coils, whose inner diameter is 560 mm, outer diameter is 1200 mm, and axial length is 1100 mm. The uniformity of designed magnetic field is under 2.0 ppm (250 mmDSV).