Abstract
Atomistic modeling of radiation damage through displacement cascades is deceptively non-trivial. Due to the high energy and stochastic nature of atomic collisions, individual primary knock-on atom (PKA) cascade simulations are computationally expensive and ill-suited for length and dose upscaling. We describe a reduced-order atomistic cascade model capable of predicting and replicating radiation events in metals across a wide range of recoil energies.
Our methodology approximates cascade and displacement damage production by modeling the cascade as a core-shell atomic structure composed of two damage production estimators, namely an athermal recombination corrected displacements per atom (arc-dpa) in the shell and a replacements per atom (rpa) representing atomic mixing in the core. These estimators are calibrated from explicit PKA simulations and a standard displacement damage model that incorporates cascade defect production efficiency and mixing effects.
We illustrate the predictability and accuracy of our reduced-order atomistic cascade method and discuss some applications to radiation damage in metals and alloys.
Bio
Chaitanya Deo, Ph.D.
Professor
Georgia Institute of Technology
Dr. Chaitanya Deo is the Southern Nuclear Professor of Nuclear and Radiological Engineering in the George W. Woodruff School of Mechanical Engineering. His research interests include computational modeling, materials behavior under extreme environments and structure- processing relationships in metals and ceramics. Dr. Deo has developed atomistic and microstructural models of the structure-property- processing relationships in actinide metals and alloys (U, Pu alloys) for nuclear fuel and forensics applications and studied radiation effects in materials. He earned PhD from the University of Michigan in Materials Science and Engineering and Scientific Computing.