Oak Ridge National Laboratory

Physics Division

Physics Division Seminars

Physics Division Seminars bring us speakers on a variety of physics related subjects. Usually these are held in the Building 6008 large Conference Room, at 3:00 pm on the chosen day, but times and locations may vary. For more information, contact our seminar chairman,

Alfredo Galindo-Uribarri
Tel (Office): (865) 574-6124  (FAX): (865) 574-1268

Thu., July 08, 2010, at 3:00 p.m. (refreshments at 2:40 p.m.)

Quantum methods for plasma facing materials in nuclear fusion

Allouche Alain, Centre National de la Recherche Scientifique and Université de Provence, Marseille (France)
Building 6008 Conference Room

Since the fundamental reaction processes in the plasma facing materials are very difficult, or impossible, to study in situ in a tokamak, dedicated experiments are developed on a laboratory scale by various groups of the community. However, in most cases, the elementary steps underlying the hydrogen (H/D) trapping and alloy formation mechanisms can only be completely identified through theoretical contributions in parallel with in lab simulations, and the quantum theory in the first-principles DFT formalism is the most reliable approach to determine the fundamental processes, in conjunction with molecular dynamics.

In this presentation, a brief report will be given on the quantum methods most often carried on in the domain: Hartree-Fock, multi-configuration and multi-reference algorithms. Application on atom-atom potential will also be detailed.

Key aspects of the First-Principles DFT method will be presented and applied to some systems interesting for tokamaks: graphite surface-hydrogen interaction, beryllium surface oxidation, first steps of beryllium-tungsten alloy formation, and H retention on and in metallic beryllium.

The last part of the talk will be a “prospective” section on studies that could be done on lithiated systems, i.e. lithium adsorption and intercalation in graphite and consequences on H/D retention, oxidation, building of ab initio interatomic potentials (Li -C, -H, -O, -W, -Be,…).

Local contact: Predrag Krstic, krsticp@ornl.gov (574-4701)