The high field superconducting magnet team of the Institute of High Energy Physics and the advanced superconductor team of the Institute of Electrical Engineering published their latest cooperative achievements on Feb. 2. The study, entitled "First performance test of the iron-based superconducting racetrack coils at 10 T,” was published in Superconductor Science and Technology (SUST).

Based on 100-meter-long 7-filamentary Ba122 iron-based superconductors (IBS), two racetrack coils were fabricated and tested at up to 7.5 T and 10 T, respectively. The highest quench current reached 86.7% of Ic of the short sample at 10 T, and 81.25% of the quench current under self-field.

The results show that the high field performance of the IBS racetrack coils is less dependent on the background field strength compared with other practical superconducting materials, which is similar to the IBS solenoid coils tested previously at 24 T. This shows that IBS can be a promising candidate material for high field magnet applications. It represents a new milestone since the first 100-meter-long IBS conductor was developed in 2016 and the performance test of the IBS solenoid coils at 24 T was conducted in 2019.

This work is highly regarded by SUST reviewers, who said “the new results can have a strong impact on the conductor and magnet community,” and also said that the results ”demonstrated the great potential of iron-based superconductors in the development of next-generation accelerators,“ etc. IBS represent a new class of high-temperature superconducting material discovered in 2008. Their upper critical field is higher than 100 T and their fabrication cost is relatively low, giving them unique potential advantages in high magnetic field applications.

For the next step, the team will continue to improve the current-carrying capacity and mechanical properties of IBS and develop higher performance IBS model coils and magnets.

The new generation of high field superconducting magnets with greatly improved cost performance will not only promote the construction of next-generation particle accelerators and the development of related basic science, but will also have a wide range of applications in the fields of advanced energy, medical equipment, electricity and transportation, etc.　

This work is supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB25000000), the National Key R&D Program of China (Grant No. 2018YFA0704200), and the National Natural Science Foundation of China (Grant Nos. 11675193 and 11575214).