Performances under ion irradiation of weak pinning superconductors MgB2 and Bi2Sr2Ca2Cu3Ox



A very significant figure of merit of a superconductor, for what concerns perspective applications, is related to its radiation hardness. In this paper we focus on the effect of high energy ions (4.2 GeV Au-ions) and low energy proton (3.5 MeV) irradiation on the superconducting properties of MgB2 tapes and films, respectively. Ions and energies are chosen as representative of the main radiation exposure in hard ambient. For sake of comparison, the behaviour of conventional high-Tc Superconductor with weak pinning, as Ag-sheated/Bi2Sr2Ca2Cu3Ox tapes, irradiated with 0.25 GeV Au-ions, is also reported. The main analysis methods consists in ac/dc magnetic and magneto-optical analysis. The obtained results indicate an high radiation hardness of MgB2 as a valuable figure of merit with respect to the application of this material in hard ambient, as well as, a radiation-induced significant enhancement of the critical current density and a large shift of the irreversibility line towards high temperatures in Ag-sheated/Bi-2223 tapes. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)