Note: low temperature superconductor superconducting quantum interference device system with wide pickup coil for...

Area of Science:

• Physics
• Materials Science
• Electrical Engineering

Background:

• Superconducting Quantum Interference Devices (SQUIDs) are highly sensitive magnetic field detectors.
• Developing SQUID systems with enhanced sensitivity and large sensing areas is crucial for various applications.
• Low-temperature superconductor (LTS) technology offers unique properties for sensitive instrumentation.

Purpose of the Study:

• To develop and characterize a one-channel low-temperature superconductor SQUID system.
• To evaluate the system's magnetic field sensitivity and detection capabilities.
• To assess the system's applicability in quality control for industrial products.

Main Methods:

• Development of a one-channel LTS SQUID system featuring a second-order axial gradiometer (10 mm × 190 mm).
• Mounting the gradiometer in a liquid-helium dewar with specific dimensions and coil-to-dewar gap.
• Measurement of magnetic field sensitivity, achieving 16 fT/Hz(1/2) above 2 Hz.
• Testing the system by detecting stainless steel particles (e.g., 100-μm SUS304) passing through the sensing area.

Main Results:

• The developed SQUID system demonstrated a magnetic field sensitivity of 16 fT/Hz(1/2).
• The system successfully detected a 100-μm diameter SUS304 particle, measuring its 1.3-pT magnetic field.
• Detection was feasible even when particles passed at different positions under the large pickup coil.

Conclusions:

• The developed LTS SQUID system exhibits excellent magnetic field sensitivity.
• The system is capable of detecting small metallic particles, indicating its potential for non-destructive testing.
• The SQUID system is applicable for quality control in manufacturing processes, including lamination sheet products like lithium-ion batteries.