THE INFLUENCE OF COLUMNAR DEFECTS ON THE CRITICAL-CURRENT DENSITY IN (BI, PB)2SR2CA2CU3O10-AG TAPES(DELTA)

An excellent tool to enhance the critical current density in supercond uctors is the controlled introduction of defects by irradiation damage . Irradiation with 2.65 GeV Au ions provides the generation of amorpho us line defects. Polycrystalline (Bi, Pb)2Sr2Ca2Cu3O10+delta Ag tapes processed by the powder-in-tube technique were irradiated up to doses of 3.5 x 10(11) Au ions/cm2 at a temperature of 100 K. On the one hand , our irradiation experimentws were performed to investigate the degre e of j(c) enhancement and, on the other hand, to examine the flux pinn ing mechanism in (Bi, Pb)2Sr2Ca2Cu3O10 + delta tapes. Characterization of the samples was performed by magnetization measurements using a vi brating sample magnetometer (VSM) up to 13 T in a temperature range be tween 5 and 100 K. Further, we have measured the relaxation of the mag netic moment before and after irradiation to determine the influence o f columnar defects on the activation energy U. A comparison of the irr adiation-induced effects with previous results obtained on Bi2Sr2CaCu2 O8 + delta irradiation experiments is included.