In the realm of energy research, a team of scientists from the University of Tennessee, Knoxville, and Oak Ridge National Laboratory have made significant strides in enhancing the capabilities of a software tool designed to simulate radiation damage in materials. The researchers, Uttiyoarnab Saha, Ali Hamedani, Miguel A. Caro, and Andrea E. Sand, have developed improvements to the TurboGAP software package, which is used for efficient molecular dynamics simulations. Their work was recently published in the journal Computer Physics Communications.
TurboGAP is a software package that utilizes Gaussian Approximation Potential (GAP) machine-learning interatomic potentials (MLIP) to simulate molecular dynamics. The team has enhanced TurboGAP’s capabilities for radiation damage simulations by implementing a two-temperature molecular dynamics model. This model allows for the coupling of electronic and atomic subsystems based on electron density, providing a more accurate representation of the physical processes involved in radiation damage.
In addition to the two-temperature model, the researchers have also implemented adaptive calculation of the timestep and grouping of atoms for cell-border cooling. These improvements allow for more efficient and accurate simulations of radiation-induced cascade events. The team has incorporated electronic stopping power models, both traditional friction-based models and more realistic first-principles-derived models, to better understand the interaction of radiation with materials.
Using the enhanced TurboGAP software, the researchers performed cascade simulations in silicon with primary knock-on atom (PKA) energies up to 10 keV. These simulations scaled to systems containing up to 1 million atoms, providing detailed insights into the generation and clustering of radiation-induced defects. The team also calculated ion-beam mixing and compared their results with experimental data, demonstrating how the GAP-MLIP along with the inclusion of a realistic electronic stopping model improves the prediction of experimental mixing values.
The practical applications of this research for the energy sector are significant. Understanding radiation damage in materials is crucial for the development of advanced nuclear reactors, fusion energy systems, and other energy technologies that involve exposure to high-energy radiation. The enhanced capabilities of TurboGAP will enable researchers to better predict and mitigate radiation-induced damage, leading to the development of more resilient and efficient energy technologies.
Source: Computer Physics Communications, Volume 274, April 2022, 108562
This article is based on research available at arXiv.