Temperature effects on the point defects formation in [111] W by neutron induced collision cascade

Abstract

Tungsten is used as plasma-facing wall in ITER where it is subjected to extreme operating conditions. In this work, we study the damage formation in [111] crystalline W by neutron bombardment in the temperature range of 300-900 K which is important for designing next generation of fusion reactors. The Molecular Dynamics (MD) simulations are performed at a primary knock-on atoms (PKA) energy of 1 keV within the Gaussian Approximation Potential (GAP) framework. The analysis of the induced damage is done by the Fingerprinting and Visualization Analyzer of Defects (FaVAD) which is based on a rotation invariant mapping of the local atomic neighborhoods allowing to extract, to identify and to visualize the atomic defect formation dynamically during and after the collision cascades. The evaluation allows to classify the various defect types and to quantify the defect evolution as function of time and initial sample temperature. We found that the production of Frenkel pair increases as a function of the temperature due to thermal activated mechanisms.