A 1 kA-class cryogen-free critical current characterization system for superconducting coated conductors

Area of Science:

• Materials Science
• Condensed Matter Physics
• Superconductivity Engineering

Background:

• Commercial second-generation high-temperature superconducting (HTS) wires, specifically YBa2Cu3O7 coated conductors, require precise characterization for performance evaluation.
• Existing measurement systems may lack the specialized capabilities for routine, automated, and high-current testing of these HTS wires under diverse cryogenic conditions.

Purpose of the Study:

• To describe a novel cryogenic electrical transport measurement system designed for the routine and effective characterization of commercial second-generation HTS wires.
• To detail the system's design parameters, including base temperature, magnetic field capabilities, current capacity, and sample handling.
• To highlight the system's cryogen-free operation and automated measurement capabilities for comprehensive HTS wire performance analysis.

Main Methods:

• Development of a cryogenic measurement system with a base temperature of 20 K and an 8 T magnetic field capability using a split-coil magnet.
• Integration of a high measurement current capacity approaching 1 kA and accommodation for HTS wire samples up to 12 mm in width.
• Implementation of sample rotation for field angle variation and cryogen-free cooling for both sample and magnet.
• Development of automated software for characterizing temperature, magnetic field, and field angle dependence of critical current.

Main Results:

• The system successfully measures critical current characteristics of various HTS wire samples under diverse operating conditions.
• Demonstration of cryogen-free operation for both sample cooling and magnet operation, eliminating the need for liquid cryogens.
• Successful characterization of HTS wires across a range of temperatures, magnetic fields, and field angles with automated software.

Conclusions:

• The developed cryogenic system represents a significant advancement in HTS magnet design and cryogen-free cooling technologies.
• The system provides routine and automated high-current electrical transport measurements at cryogenic temperatures, crucial for HTS wire characterization.
• This system is valuable for both research scientists studying superconductor behavior and commercial manufacturers assessing product performance.