MgB₂ Superconducting Joint Architecture with the Functionality to Screen External Magnetic Fields for MRI Magnet...

Area of Science:

• Superconductivity
• Materials Science
• Applied Physics

Background:

• Superconducting joints are critical for applications like magnetic resonance imaging (MRI) magnets.
• Existing joints often exhibit lower critical current performance than the wires themselves, especially under applied magnetic fields.
• Magnesium diboride (MgB₂) is a promising superconductor due to its relatively high critical temperature and field performance.

Purpose of the Study:

• To propose and demonstrate a novel superconducting joint architecture for carbon-doped multifilament MgB₂ wires.
• To achieve magnetic field screening functionality within the joint itself.
• To enhance the performance and reliability of MgB₂ wires in demanding applications like MRI magnets.

Main Methods:

• Fabrication of a superconducting joint utilizing the intrinsic diamagnetic property of MgB₂ bulk.
• Integration of a magnetic field screening mechanism directly into the joint architecture.
• Characterization of the joint's performance, including critical current (I_c) and resistance, under various magnetic fields and temperatures.

Main Results:

• The proposed joint architecture successfully screened external magnetic fields up to 1.5 T at 20 K and 2 T at 15 K.
• The joint maintained a constant critical current (I_c) by effectively nullifying the applied magnetic field's effect.
• Achieved an I_c of 30.8 A in 1.5 T at 20 K and an ultralow resistance of 3.32 × 10^-14 Ω at 20 K in a self-field.

Conclusions:

• The novel MgB₂ joint architecture provides significant magnetic field screening capabilities.
• This technology is highly valuable for MRI magnet applications, addressing the common issue of joint-limited critical current.
• The development paves the way for more robust and efficient superconducting systems utilizing MgB₂ wires.