Displacement cascades and defects annealing in tungsten, Part II: Object kinetic Monte Carlo Simulation of Tungsten Cascade Aging

TL;DR

This paper uses object kinetic Monte Carlo simulations to study how primary cascade damage in tungsten anneals at different temperatures, revealing complex defect behaviors and introducing a new simulation code.

Contribution

It presents a comprehensive OKMC simulation approach for tungsten damage annealing, incorporating a detailed cascade database and a new simulation code, KSOME.

Findings

Annealing efficiency shows an inverse U-shape with temperature.

Temperature affects SIA and vacancy clustering differently.

The simulation code KSOME effectively models microstructure evolution.

Abstract

We describe the results of object kinetic Monte Carlo (OKMC) simulations of the annealing of primary cascade damage in bulk tungsten using a comprehensive database of cascades obtained from molecular dynamics [1] as a function of primary knock-on atom (PKA) energy and direction, and temperatures of 300, 1025 and 2050 K. An increase in SIA clustering but decrease in vacancy clustering with temperature combined with disparate mobilities of SIAs versus vacancies causes an interesting temperature effect on cascade annealing, which is quite different from what one would expect. The annealing efficiency (ratio of number of defects after and before annealing) exhibits an inverse U-shape curve as a function of temperature. In addition, we will also describe the capabilities of our newly developed OKMC code; KSOME (kinetic simulations of microstructure evolution) used to carryout these simulations