Superconducting Properties and Microstructure of In-situ Cu Addition Low Activation MgB₂ Multifilamentary Wires Using Different Boron-11 Isotope Powders

Abstract

MgB₂ compound is one of the low activation superconducting materials because the half-life time of the MgB₂ phase is much shorter than that of the Nb-based superconductors, such as Nb-Ti and Nb₃Sn. The natural boron powder as the boron source of the in-situ MgB₂ wire and bulk consists of two kinds of stable isotope materials, which are B-10 (¹⁰B:19.78 %) and B-11 (¹¹B: 80.22 %) isotopes. The ¹¹B isotope is a promising raw material for the further improvement of the neutron irradiation effect on the low activation MgB₂ wire. This study focused on the quality effect of the ¹¹B isotope raw powder on the superconducting properties of the ¹¹B isotope-originated MgB₂ (Mg¹¹B2) wire. We found that the nano-order particle size and the higher purification of the ¹¹B isotope raw powder would be efficient in the improvement of the superconducting properties of the low activation Mg¹¹B₂ wire.