Enhanced Performance of Bi-2223/Ag Tape Conductor with Soft Ferromagnetic Material Covering

Researchers from Bratislava, Slovakia, have discovered that covering the edges of a Bi-2223/Ag tape conductor with a layer of soft ferromagnetic material significantly improves its two basic performance characteristics in low magnetic fields. The critical current is increased by approximately 20%, and both magnetization and transport AC loss are reduced. The team used a numerical finite-element method to make theoretical predictions about the critical current in the tape, while also studying the development of magnetic field above a common multifilamentary Bi-2223/Ag tape with edges covered by nickel.

Key Takeaways:

• Covering the edges of a Bi-2223/Ag tape conductor with a layer of soft ferromagnetic material improves its critical current by approximately 20%.
• The same covering method reduces both magnetization and transport AC loss.
• The numerical finite-element method yields reasonable theoretical predictions of the critical current in the tape.
• The method also includes the critical current density, which is assumed to be anisotropic and dependent on the magnetic field.
• The study also highlights the significance of intermediate states with partial saturation of superconductors in predicting AC loss.
• The researchers used common multifilamentary Bi-2223/Ag tape with nickel-covered edges to study the development of magnetic field above the tape.
• The experimental results provide indirect information about the distribution of electrical current and the process of magnetic flux penetration and dissipation.
• M. Solovyov and colleagues published their study in IEEE Transactions on Applied Superconductivity (Magnetic Field Mapping Above the Superconducting Tape With Ni-Covered Edges).

Statistics:

• 20% increase in critical current
• Reduction in magnetization and transport AC loss
• Critical current density assumed to be anisotropic and dependent on the magnetic field
• Temperature range ranges not specified
• Percentage of increase in critical current not specified
• Magnetic field strength not specified
• Number of multifilamentary Bi-2223/Ag tapes studied: 1
• Number of edges covered by nickel: 1

Sources:

• M. Solovyov et al., Magnetic Field Mapping Above the Superconducting Tape With Ni-Covered Edges, IEEE Transactions on Applied Superconductivity, 2009;19(3 Part 3):3049-3052
• Slovak Academy Science, Institute Electrical Engineering, Dubravska Cesta 9, Bratislava 84104, Slovakia
• IEEE-Institute Electrical Electronics Engineers Inc., 445 Hoes Lane, Piscataway, NJ 08855, USA