[WBP1] Conductor Processing & Evaluation

[WBP1-03] Research Progress of Bi-2212 Superconducting Material at WST

*Guo Yan¹ (1. Western Superconducting Technologies Co., Ltd (China))

Keywords:

Bi-2212,Critical Current,High-pressure Heat Treatment

The Bi-2212 superconducting material has an extremely high upper critical field. It is the only high-temperature superconducting material that can be fabricated into isotropic round wires, and it shows significant application potential in fields such as accelerators, nuclear magnetic resonance, high-field magnets, and nuclear fusion. Based on the powder-in-tube technical route, Western Superconducting Technologies Co., Ltd. (WST) has developed Bi-2212 superconducting wires with a 990-core structure and a length of up to 1000 meters, as shown in Figure 1(a). Bi-2212 wires can maintain good uniformity within the diameter range of 0.8 - 1.0 mm and can be stably produced in batches. Critical currents (I_c) of up to 783 A and critical current densities (J_c) of up to 5333 A/mm²were achieved for 1 mm diameter wires under atmospheric pressure heat treatment, as demonstrated in Figure 1(b). For Bi-2212 superconductor wires, the application of high-pressure heat treatment has been shown to have a significant effect on the densification of the core wires. This, in turn, has been demonstrated to result in an increase in the J_c of the wires. Our research team also conducted a study on the high-pressure heat treatment of Bi-2212 superconductor wires. The study found that the I_c of the wires reached 1132 A under 5 MPa, marking a 44.6% improvement. The high-pressure heat treatment work is currently being optimised, with scope for further improvement of the I_c of Bi-2212 wire in the future.