Table of Contents
Research Letters in Physics
Volume 2008 (2008), Article ID 746892, 4 pages
http://dx.doi.org/10.1155/2008/746892
Research Letter

Computer Modeling of Displacement Cascades in Beryllium Irradiated with Intensive Neutron Flux

Institute for Nuclear Research and Nuclear Energy, 72 Tzarigradsko Chaussee Boulevard, Sofia 1784, Bulgaria

Received 21 October 2007; Accepted 3 January 2008

Academic Editor: William Dorland

Copyright © 2008 T. Troev et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Computer simulations of the radiation defects created in beryllium irradiated by fast neutrons ( 𝐸 > 0 . 1  MeV) using the Geant4 and SRIM packages were carried out. The atom cascade displacements in Be at a neutron fluence of 1 . 6 × 1 0 2 0  n/c m 2 were determined to be 0.06 dpa and the helium concentration was calculated to be 168 appm. The concentration of 6 L i has been estimated to be 5% in comparison to the He concentration. Nanoscale calculations were done in 3 0 × 3 0 × 3 0  nm cube of fast neutron-irradiated Be. A correlation between the Be primary knock-on atom (PKA) energies and the damage cascades has been established. The final defect distributions of single vacancies, divacancies, and small vacancy clusters were examined. Our results indicate that the damages caused by He atoms are about 3 times less than damages caused by Be primary knock-on atoms (PKAs).