16th International Workshop on Spallation Materials Technology (IWSMT16)

Characterization of Helium Bubble Formation in FeCr Alloys Using Positron Annihilation Lifetime Spectroscopy

Not scheduled

5m

The Cosener's house

Fundamental studies on the effects of radiation damage in materials. Innovative radiation damage resistant materials technology. Poster session

Speaker

Vladimir Krsjak (Slovak University of Technology, Institute of Nuclear and Physical Engineering, Ilkovicova 3, 812 19, Bratislava, Slovakia)

Description

Positron annihilation lifetime spectroscopy (PALS) has been used to improve the understanding and prediction of early-stage helium-assisted radiation aging of structural materials. The present study integrates a unique high-energy helium ion irradiation experiment with spallation target irradiation experiments, offering experimental PALS data that reveal the microstructure and a wide range of radiation-induced cluster sizes. Through these analyses, the study estimates the helium-to-vacancy ratio and enhances the existing theoretical model of positron trapping coefficients to account for cluster size and irradiation temperature. The findings confirm the model's effectiveness in characterizing helium-vacancy clusters and helium bubbles up to 1 nm in diameter, formed at irradiation temperatures ranging from room temperature to 300°C. This validation underscores the feasibility of using helium implantations for experimentally simulating spallation radiation environments.