Size-distribution of irradiation-induced dislocation-loops in materials used in the nuclear industry

DOI: 10.1016/j.jnucmat.2021.152945

Authors: Tamás Ungár (The University of Manchester; Eötvös University Budapest) , Philipp Frankel (The University of Manchester) , Gábor Ribárik (Eötvös University Budapest) , Christopher P. Race (The University of Manchester) , Michael Preuss (The University of Manchester)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Journal Of Nuclear Materials , VOL 550

State: Published (Approved)
Published: July 2021
Diamond Proposal Number(s): 8395 , 10006

Abstract: Neutron or proton irradiation induced dislocation loops in Zr and its alloys are usually characterized by electron microscopy methods. In plastically deformed materials X-ray line profile analysis (XLPA) is now a well-established tool to determine dislocation densities (DDs) with excellent agreement between XLPA and TEM analysis. In irradiated zirconium alloys, however, XLPA determined DDs are often considerably larger than those obtained by TEM. In ion irradiated Cu and W it was shown that X-ray diffraction or MD simulations give significantly larger dislocation loop densities than conventional TEM analysis, which suggests that the smallest loops remain undetected by TEM. Based on these results we developed a new methodology to determine power-law size-distributions of irradiation-induced dislocation loops. We assume that only loops larger than a certain threshold are fully counted in TEM micrographs, whereas XLPA detects all the loops in the entire size range. This new analysis procedure shows that in neutron irradiated Zircaloy-2 in the channel-box materials the total DD is larger than in the cladding materials, even though TEM counting shows the opposite. We also found that there is a correlation between the reciprocal square-root of loop DDs and the diameter of loops. Our work shows that irradiation induced loop-formation and irradiation-damage in general can be better determined when we combine TEM investigations with XLPA.

Journal Keywords: Irradiation-induced dislocation-loops; Size-distribution of loops; X-ray line profile analysis; Correlation between dislocation-density and loop-diameter; Combination of XLPA and TEM

Subject Areas: Materials, Physics


Instruments: I11-High Resolution Powder Diffraction

Discipline Tags:

Material Sciences Radioactive Materials

Technical Tags:

Diffraction X-ray Powder Diffraction