Preparation of High-Field Nb_3(Al, Ge) and Nb_3Al Superconductors by Liquid Quenching and High-Energy Beam Techniques (Low-T_c Superconducting Materials Research)

Nb_3Al and its ternary compounds tapes have been prepared by continuous liquid quenching and high energy beam irradiation and Jc of the tapes has been measured in fields up to 23T. The Nb_3Al, Nb_3(Al, Ge) and Nb_3(Al, Si) alloy tapes prepared by the continuous liquid quenching have an extremely small grain size which is enough to ensure a strong flux pinning and hence high critical current density. Jc at 4.2K reaches 10^5A/cm^2 at 20T. Continuous high energy beam irradiation has been performed for Nb-Al and Nb-(Al-Ge) tapes made by powder metallurgy process. High Tc and excellent high field Jc properties have been achieved by the irradiation and subsequent annealing. Overall Jc\u27s exceeding well 10^4A/cm^2 have been obtained at 23T and 4.2K for the Nb-Al and Nb-(Al-Ge) tapes

Mechanical properties and reinforcement of Bi-2212 tubular bulk superconductor for current lead

High-Tc superconductor has been expected as a current lead between a low Tc superconductor and a power supply for a large-scale superconducting magnet system because of its advantages of a heat load to a cryogenic system and a high transfer current density. Bi-2212 bulk superconductor is a candidate material for this kind of current lead. To design a current lead using high-Tc superconductor, we investigated mechanical properties of a Bi-2212 bulk which was prepared by a diffusion process. A concept design of a current lead reinforced by using a glass-epoxy was considered