Unraveling Alternative Routes for Materials Interfacing Fusion Plasmas

Prof. P.S. Krstic       J. Dominguez

Plasma-Material Interface (PMI) science mixes the worlds of plasma and materials, creating in-between a new entity, a dynamical interface that is actively evolving between the two producing one of the most challenging areas of multidisciplinary science. This area has many spatio-temporal fundamental processes and synergies driven by both the plasma side of the interface and material transformation on the other. A major goal in PMI science is to extend high-performance plasmas for very long durations and to integrate this performance with Plasma-Facing Components (PFCs) that can withstand high heat and particle fluxes while maintaining structural integrity and minimal retention of fusion fuel. Among the most elusive technical challenges for the advancement of thermonuclear magnetic fusion energy is predictive control of hydrogen recycling in the PFCs as well as management of erosion and defects induced by plasma particle and neutron irradiation.

IACS researchers, Javier Dominguez and Predrag Krstic, have used atomistic simulations and validate them with experimental in situ studies with x-ray photoelectron spectroscopy, to understand the effects of deuterium irradiation on the chemistry in lithiated, boronized and oxidized amorphous carbon surfaces, possible alternative materials for PFCs. They explain the important role of oxygen in D retention for lithiated surfaces and the suppression of oxygen role by boron in boronized surfaces. The sputtering yield per low energy D impact is   significantly smaller in boronized than in lithiated surfaces. Their work has been recently published in a series of papers like are Journal of Nuclear Materials and Journal of Applied Physics.