NachhaltigAngewandte Naturwissenschaften und Wirtschaftsingenieurwesen
Thomas Stirner, Ali Hamid, Jizhong Sun, Hongyu Zhang, Arvind Jadon
Molecular dynamics simulations of helium clustering and bubble growth under tungsten surfaces
Computational Materials Science, vol. 163, no. June, pp. 141-147
We study the surface response of W to helium bombardment using molecular dynamics simulations. Simulations have been performed for incident helium of energy 80 eV and surface temperature 2100 K. The saturation of He retention has been observed to be high, a result of the bubbles trapping helium atoms and preventing them from diffusing to the surface and further back into the plasma. On the other hand, we have observe near-surface “cluster rupture” leading to the expulsion of helium atoms towards the vacuum. We have found that bubbles typically grow in a relatively narrow band of He/V ratios (1–3). Besides, it was observed that tungsten atoms migrated from the top surface into the bulk. The coalescence of helium bubbles has also been observed.
Angewandte Naturwissenschaften und Wirtschaftsingenieurwesen
Jizhong Sun, Thomas Stirner
Molecular Dynamics Simulation of the Surface Pressure of Colloidal Monolayers
Langmuir, vol. 17, no. 10, pp. 3103-3108
The compression of two-dimensional colloidal monolayers consisting of polystyrene particles at an oil−water interface is investigated theoretically. Expressions for the pair−particle interactions are derived both for point particles and for particles of radius R. The resulting expressions for the interaction energies are employed in a molecular dynamics simulation of the surface pressure of these monolayers. A comparison of the theoretical results with recent observations allows the determination of the dominant interaction mechanisms in the experimental system. Possible physical interpretations of the interaction mechanisms between the particles are discussed.