Radiation effect of swift heavy ions on current-carrying capability of commercial YBCO coated conductors

This paper presents the swift heavy ions irradiation effects in commercial Gd-doped YBCO (YGd 0.2 Ba 2 Cu 3 O 7−x ) coated conductors irradiated by 1.9 GeV 181 Ta ions with a wide range of ion fluences. Both continuous latent tracks produced by incident ions and nonuniform inclusions induced during film manufacture can be observed from TEM images, proving the existence of mixed-pinning landscapes. Onset critical temperature T c,on is almost unchanged (△ T c,on ≈ 0.5 K) when irradiated at optimal fluence of 5.0 × 10 10 ions/cm 2 , whereas in-field critical current J c increased to a factor of more than 2 over a wide range of magnetic field at 77 K. Moreover, the value of α in power-law regime has been reduced to 0.31, compared to 0.72 for pristine sample, indicating slower J c decay with magnetic field after Ta ions irradiation. Peak value of J c, irradiated /J c, pristine curve appears when external magnetic field is near matching field at which the density of vortice equal to ion fluence. Experimental results proving that latent tracks can further enhance in-field current-carrying capability of commercial YBCO coated conductors.