Research Progress on Irradiation Effect of Superconducting Materials

Due to a series of excellent properties such as zero resistance effect, Meissner effect, Josephson effect, superconducting materials have been gradually applied in information energy, electric transportation, scientific instruments, medical technology, national defense and military and other important fields, which has strongly promoted the development of the national economy and human society. At present, the irradiation effect of superconducting materials in extreme environments such as strong magnetic field, strong radiation and ultra-low temperature is a hotspot of widespread concern among researchers at home and abroad. Under the action of high-energy particle bombardment, atoms in the lattice of superconducting materials have a series of collisions, resulting in a large number of irradiation defects (such as dissociation peaks, atom-poor regions, empty sites, interstital atoms, dislocations, cavities), defect clusters and new precipitates. These have significant effects on its superconducting properties (critical temperature TC, critical magnetic field HC, critical current IC and critical current density JC, etc.). The research progress of irradiation effect of different superconducting materials is reviewed in this paper. According to the critical temperature TC classification, superconducting materials can be divided into low temperature superconducting materials (TC < 25 K, mainly NbTi, Nb3Sn and Nb3Al) and high temperature superconducting materials (TC > 25 K, mainly bismuth, yttrium, MgB2 and iron-based superconducting materials). The irradiation sources (including neutrons, ions (He, B, C, O, Ne, Si, Ar, Ti, Ni, Xe, Au, Pb, etc.), protons, electrons and rays (γ, χ ray)), irradiation conditions (energy, dose, temperature), initial state of superconducting materials, doping ( MgO, B, Sn, Ag, etc.) and other factors on its superconducting properties. A large number of studies have shown that superconducting materials can introduce defects after irradiation, the strength and density of flux pinning increase, and the critical current density JC is improved. In addition, adding carriers in superconducting materials or improving the ordering of crystals can increase the critical temperature TC. Finally, in view of some key problems that need to be solved in current superconducting materials, the technical approaches to improve the irradiation effect of superconducting materials by optimizing the material system and its preparation process, heat treatment, doping, and the combination of numerical simulation and experiment are proposed, which provide ideas for the research, development and commercial application of superconducting materials.