Positron annihilation as an additional source of information about plastic deformation in structural materials

Contribution of cadmium to the total amount of positron creation in a reactor-based slow positron beamline

“…Although prompt gamma-rays emitted from Cd are used in the KUR slow positron beamline to enhance the quantity of positron creation, the use of other materials having large neutron-capture cross sections is also worth consideration [17,35,36]. The 157 Gd(n,γ) 158 Gd, 155 Gd(n,γ) 156 Gd, and 149 Sm(n,γ) 150 Sm reactions may be effective, since the neutron-capture cross sections of 157 Gd, 155 Gd, and 149 Sm have large values of 254000 barns, 60900 barns, and 40140 barns, respectively [25].…”

Slow-positron beamline temperature rise reduction at Kyoto University Research Reactor

“…Gadolinium is worth considering as another material that has a large thermal neutron capture crosssection and emits prompt gamma-rays. The use of gadolinium in reactor-based positron sources has also been considered by other groups [16,17]. However, there was no consensus on whether cadmium or gadolinium is advantageous in enhancing positron creation.…”

Grain boundary misorientation and positron annihilation characteristics in steel Eurofer processed by equal channel angular pressing

“…Positron annihilation spectroscopy (PAS) is a wellestablished technique to study vacancy-type defects such as vacancies, dislocations, voids, and other open-volume defects in metals [23][24][25][26]. Positron lifetime measurements at room temperature were performed on Eurofer in the as-tempered and ECAP-deformed conditions, as well as after being tensile tested up to fracture, in order to obtain information about the nature of the vacancy-types defects present in the Eurofer steel and their evolution after ECAP deformation and subsequent tensile deformation.…”