Watch-sized 12 Tesla all-high-temperature-superconducting magnet

Area of Science:

• Materials Science
• Physics
• Engineering

Background:

• High magnetic fields are crucial for advanced applications like nuclear magnetic resonance (NMR).
• Traditional superconducting magnets are often large, expensive, and difficult to site.
• Developing smaller, more accessible high-field magnets is a key technological goal.

Purpose of the Study:

• To demonstrate the construction of compact 7 Tesla and 12 Tesla all high-temperature-superconducting (HTS) magnets.
• To explore the benefits of miniaturization, including reduced cost, fringe field, and stored energy.
• To develop HTS magnets for gyrotron microwave sources used in high-field NMR.

Main Methods:

• Fabrication of 7 Tesla and 12 Tesla magnets using all high-temperature-superconducting (HTS) tapes.
• Employment of a no-insulation winding technique.
• Cooling the magnets to 4.2 Kelvin in a liquid helium cryostat.

Main Results:

• Successfully constructed a 7 Tesla single pancake coil magnet (8mm inner diameter, 24mm outer diameter) using 9.4m of HTS tape.
• The 7 Tesla magnet achieved a field of 7.3 Tesla at 1168 Amperes.
• Built a 12 Tesla magnet with two series-connected pancake coils (10mm inner diameter, 27mm outer diameter), reaching maximum field at 850 Amperes.

Conclusions:

• Demonstrated the feasibility of creating small, high-field HTS magnets suitable for wrist-worn applications.
• The developed magnets offer significant advantages in terms of size, cost, and siting for high-field NMR.
• These compact HTS magnets represent a promising advancement for gyrotron microwave sources and related technologies.