Our interest in nuclear data extends from the nuclear interaction itself into the results from the subsequent electronic interactions of the recoil products. Thus, we have research efforts that investigate the evolution of more complex defects from the initial recoil atoms using molecular dynamics (MD) and density functional theory (DFT). Much of our research focuses on electronic materials, such as silicon, GaAs, and GaN, but we also look at radiation embrittlement of structure materials, such as the iron in light water reactor pressure vessels. We examine, from a theoretical and experimental perspective, the equivalence of ion irradiations and neutron irradiations and support standards development by ASTM E10.08 – Procedures for Neutron Radiation Damage Simulation. Our interest extends beyond the time regimes explored by MD into modeling that used kinetic Monte Carlo kMC) approaches and mean field rate theory (MFRT).
Contact: Edward Bielejec
Publications
- W.R. Wampler, et al., “Model for transport and reaction of defects and carriers within displacement cascades in gallium arsenide,” Journal of Applied Physics, Vol. 117, 2015
- S.M. Myers, et al., “Model of defect reactions and the influence of clustering in pulse-neutron-irradiated Si”, J. Applied. Phys., Vol. 104, 044507, 2008, online
- R.M. Fleming, et al., “A bistable divacancy-like defect in silicon damage cascades,” Journal of Applied Physics, Vol. 104, 083702, 2008
- R.M. Fleming, et al., “Defect-driven gain bistability in neutron damaged, silicon bipolar transistors,” App. Phys. Lett., Vol. 90, 172105, 2007
- R.M. Fleming, et al., “Effects of clustering on the properties of defects in neutron irradiated silicon,” J. App. Phys., Vol. 102, 043711, 2007
- W.R. Wampler, S.M. Myers, “A drift-diffusion model for gain degradation from pulsed neutron irradiation in silicon bipolar transistors,” SAND2006-5770J, (internal access only).
- S.M. Foiles, “Detailed characterization of defect production in molecular dynamics simulations of cascades in Si,” Nucl. Instr. Meth. Phys. Res. B, Vol. 255, pp. 101-104, 2007
- B.D. Hehr, “Analysis of Radiation Effects in Silicon using Kinetic Monte Carlo Methods,” IEEE TNS, Vol. 61, 2014
- B.D. Hehr, “LDRD Report: Analysis of Defect Clustering in Semiconductors using Kinetic Monte Carlo Methods,” SAND2014-0261
- D.B. King, et al., “Experimental Comparison of Neutron and Ion Damage in a PnP III-V HBT,” Journal of Radiation Effects Research and Engineering, Vol. 33, No. 1-E, May 2015. Also available as SAND2015-4206J. (limited access).
- P.J. Griffin, et al., “Application of spallation neutron sources in support of radiation hardness studies,” Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 562, pp. 684-687, June 2006