Optical properties of tungsten surfaces submitted to fusion reactor conditions
This 3 years PhD thesis is offered in the framework of the collaborative project WHeSCI (piim.univ-amu.fr/amidex/whesci), financed by the A*MIDEX foundation (amidex.univ-amu.fr) and proposed in the context of the International Thermonuclear Experimental Reactor (ITER), the international project that aims to demonstrate the technological and scientific feasibility of fusion energy with the Tokamak design (www.iter.org). The WHeSCI project seeks to describe the interactions of the fusion fuel (deuterium and tritium ions) and ashes (helium ions and neutron) with the walls of the exhaust of the reactor (the divertor made of Tungsten, W). The induced material properties modifications are indeed critical for the reactor operation and safety and the successful operation of ITER requires a detailed understanding of the plasma-wall interactions.
In this context, the PhD candidate will be particularly involved in the study of the optical properties of W samples and their evolution with the (near-) surface properties (implanted ions, oxidation, microstructure, roughness…) and applied heat loads (temperature gradients). This work will involve experimental development allowing performing ellipsometric measurement on laser-heated samples from 120 K to > 2000 K in well-controlled conditions (Ultra High Vacuum) and on a variety of W samples, from model (single crystal) to realistic tokamak materials. The experiments analysis will be associated with modelling for the description of ion interactions with W and for the description of the optical properties dependencies with intrinsic material properties and surface state.
The position is based at both the PIIM laboratory and the Institut Fresnel (same campus in Marseille, Provence, France). A highly motivated and experimentally skilled individual is sought, with strong background in physics or chemical physics, knowledge in high vacuum and optics being a plus.
- Minissale M, Pardanaud C, Bisson R and Gallais L, “The temperature dependence of optical properties of tungsten in the visible and near-infrared domains: an experimental and theoretical study” Journal of Physics D: Applied Physics 50, 455601 (2017)
- Hodille EA, Ghiorghiu F, Addab Y, Založnik A, Minissale M, Piazza Z, Martin C, Angot T, Gallais L, Barthe M-F, Becquart CS, Markelj S, Mougenot J, Grisolia C and Bisson R, “Retention and release of hydrogen isotopes in tungsten plasma-facing components: the role of grain boundaries and the native oxide layer from a joint experiment-simulation integrated approach”, Nuclear Fusion 57, 076019 (2017)