Speaker
Description
High-temperature superconductors (HTS) REBCO (Rare Earth Barium Copper Oxide) tapes are key candidates for applications in fusion reactors and high-energy particle accelerators due to their excellent critical current densities and high magnetic field tolerance. However, their performance in radiation-intensive environments, particularly under neutron irradiation, remains a crucial research question. This study investigates the impact of neutron irradiation on the critical properties of REBCO tapes, using a combination of macroscopic superconducting performance tests and microscopic structural characterizations. Samples with different doping levels were irradiated with neutrons at doses ranging from 1.0×10^22 to 5.0×10^22 n/m^2. Magnetic induction was employed to determine the critical transition temperature (Tc) and critical current density (Jc), analyzed under varying magnetic fields and temperatures (30 K, 50 K, and 77 K). Transmission electron microscopy (TEM) and neutron diffraction were used to examine irradiation-induced structural changes. Results indicate a dose-dependent Tc reduction and distinct trends in Jc. At 30 K, Jc decreases under low magnetic fields but improves under high fields due to enhanced flux pinning. At 50 K, Jc shows minimal changes, while at 77 K, Jc declines across all does due to dominant thermal activation effects. Notably, higher doping levels mitigate the Jc reduction, highlighting doping as a promising approach to enhance radiation tolerance. TEM analysis revealed irradiation-induced defect clusters and dislocation that contribute to enhanced pinning, while neutron diffraction confirmed lattice distortions correlating with changes in superconducting properties. These findings reveal the interplay between irradiation-induced pinning and thermal activation effects in REBCO tapes and provide guidance for designing advanced HTS materials for radiation-intensive environments, such as fusion reactors and high-energy physics facilities.
