Atomistic calculations are presented which demonstrate that helium atoms in a metal lattice are able to cluster with each other, producing vacancies and nearby self-interstitial defects. Even a small number of helium atoms is found to be sufficient to create these large distortions. As few as five interstitial helium atoms can spontaneously produce a lattice vacancy and nearby self-interstitial. An eight-helium-atom cluster gives rise to two such defects, and 16 helium atoms to more than five self-interstitial vacancy pairs. It was noted that the self-interstitials prefer to agglomerate on the same "side" of the helium cluster rather than to spread themselves out uniformly. The binding energy of each additional helium atom to these clusters increases with helium concentration and the trap is apparently unsaturable. A rate theory using these atomistic binding energies has been used to calculate the kinetics of helium-bubble nucleation and growth. The results are consistent with measurements of the properties of helium resulting from tritium decay.
Collision cascades are investigated in MgO at energies ranging from $400\phantom{\rule{0.3em}{0ex}}\mathrm{eV}\phantom{\rule{0.3em}{0ex}}\text{to}\phantom{\rule{0.3em}{0ex}}5\ph...
Radiation damage events at low and moderate energies (up to 400 ev) are studied by machine calculations in a model representing copper. Orbits of knock-on atoms are found and th...
We develop the embedded-atom method [Phys. Rev. Lett. 50, 1285 (1983)], based on density-functional theory, as a new means of calculating ground-state properties of realistic me...
It is illustrated how an interplay between theoretical predictions and experimental measurements of binding energies or enthalpies and the corresponding equilibrium positions of...
Abstract Estimates are made of the energies of interstitial and substitutional solutions of inert gas atoms in a simple metal. The loss of cohesion round such an atom is taken i...
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