Rearrangement of interstitial defects in alpha-Fe under extreme condition

Microscopic structure of a heavily irradiated material

“…At a cDPA value of about 0.5, a third and final approximate linear regime is entered, which may be associated with the coalescence of interstitial dislocation loops, and the beginning of the development of an extended system-spanning dislocation network. The presence of a maximum of dislocation density at a dose close to φ ∼ 0.1 cDPA was also noted in a study by Chartier and Marinica [56].…”

“…Indeed, a common-neighbor analysis of the evolving microstructure revealed only a very small icoshadral content during the dislocation loop nucleation regime, where in a few cases small clusters of Laves back-bone polyhedral structures were observed. The much larger clusters seen in the work of Chartier and Marinica [56] were not found. Figure 3 displays the evolution of the interstitial/vacancy percentage content as a function of cDPA.…”

“…While the study was primarily focused on the exploration of the interplay between the dislocation microstructure and small inclusions of the Laves C15 phase, the authors of Ref. [56] noted several remarkable features of microstructural evolution, including a nonmonotonic variation of the density of dislocations across the DPA range from 0.01 to 1 cDPA, and the emergence of an asymptotic microstructural state that we explore here in detail. By comparing tungsten and iron, we show that the dynamic microstructural transition occurring in the range of doses close to 0.1 cDPA is a general phenomenon, unrelated to the presence of the C15 phase in the material.…”

“…In this limit the canonical DPA represents a natural choice of a parameter describing defect production, and in what follows will be referred to as cDPA. An algorithm similar to CRA has recently been applied to the investigation of accumulation of defects in pure iron by Chartier and Marinica [56]. While the study was primarily focused on the exploration of the interplay between the dislocation microstructure and small inclusions of the Laves C15 phase, the authors of Ref.…”

Analysis of strain and disordering kinetics based on combined RBS-channeling and X-ray diffraction atomic-scale modelling

“…Radiation damage was reproduced with the Frenkel pair (FP) accumulation method which has the advantage of bypassing the collision cascade stage and directly simulates the evolution of defects by continuously introducing FP or by reaching a nal concentration of FP at once, resulting in considerably shorter computing times [30,31]. It has proven ecient to study the complete disordering processes in Ni and Ni-based alloys [32], in UO 2 [33], but also the amorphization processes in lanthanum pyrozirconate [30] and SiC [34], and the complex defects in irradiated Fe [35].…”