Study of {alpha}-particle injection effect on superconductors YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} type

Various techniques exist to qualify and quantify this radiation damage effect. The methods are based on destructive methods such as TEM, SEM, CREEP and others. This work is intended to be a starting point to the application of nondestructive techniques to study radiation damage in superconductors in nuclear application, and a creation of a nuclear data bank for different type of materials. The first scheduled nondestructive technique to be applied is positron annihilation, more specifically positron lifetime measurements. This work is based on the implementation of a technique, widely used to simulate neutron radiation effects on materials. This simulation is obtained by the injection of charged particles (ions), from an accelerator, and a beam line equipped with some special experimental arrangement to get a homogeneous distribution of injected particles in the sample. After the ion injection, or neutron damage simulation, the nuclear data are collected by different experimental setups: conventional gamma spectrometer for activation analysis, X-ray diffraction for phase change analysis, and zero detector for magnetic permeability measurements. The behavior of the magnetic permeability with temperature of YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} superconducting ceramics was studied as a function of the amount of He{sup {minus}2} implanted into the sample. With fluence varying from 1.2 to 6.0 {times} 10{sup 6} He{sup {minus}2} cm{sup {minus}2}, the results show that the superconducting temperature T{sub c}(onset) stays nearly constant up to 2.5 {times} 10{sup 6} He{sup {minus}2} cm{sup {minus}2}, decreasing afterwards for higher fluencies. An almost linear decrease is observed for T(offset). The magnetic permeability curves show structures whose shapes and relative positions to T{sub c}(onset) change with the fluence. Although this might indicate a mixture of phases coexisting inside the sample, X-ray diffraction shows no clear evidence for such a pattern. A large percentage of the damage recovers after annealing the He-implanted sample at 673 K