Taming the plasma-material interface in plasma-burning nuclear fusion reactors

Jean Paul Allain

University of Illinois at Urbana-Champaign

Friday, October 13, 2017

3:00pm

NW17-218

PSFC Seminars

Abstract: Although progress has been made in the last half-decade in establishing an understanding of plasma-material interactions (PMI), there remain critical knowledge gaps, particularly predicting the behavior at the plasma-material interface under reactor-relevant fusion plasma conditions in a future plasma-burning neutron-dominated environment. At this interface, high particle and heat flux from the fusion plasma can limit the material’s lifetime and reliability and therefore hinder operation of the fusion device. This region is critical to operation of a nuclear fusion reactor since material can be emitted both atomistically (e.g. through evaporation, sputtering, etc.) and/or macroscopically (i.e. during transients events, such as disruptions or edge localized modes). The environmental conditions at the plasma-material interface of a future nuclear fusion reactor interacting will be extreme. The incident plasma will carry heat fluxes of the order of 100’s of MWm^-2 and particle fluxes that can average 10²⁴ m^-2s^-1. The fusion reactor wall would need to operate at high temperatures near 800 C and the incident energy of particles will vary from a few eV ions to MeV neutrons. Another challenge is the management of damage over the course of time. Operating at reactor-relevant conditions means the wall material would need to perform over the course of not just seconds or minutes (i.e. as in most advanced fusion devices today and in the near-future), but from months to years. Some promising breakthrough concepts have been considered such as liquid walls and low-recycling regimes that may address both radiation damage and the impact on the interaction with the plasma edge and ultimately plasma core.  This talk will focus on outlining both the challenges and promises of PMI research in nuclear fusion today and the prospects for possible solutions for future plasma-burning fusion reactors.  The talk will in part summarize the recent DOE Fusion Energy Sciences Workshop on Plasma-Material Interactions and also highlight some of the recent work in Prof. Allain’s RSSEL group at UIUC.

Bio: Prof. Jean Paul Allain completed his Ph.D. degree from the Department of Nuclear, Plasma and Radiological Engineering at the University of Illinois, Urbana-Champaign.  He received a M.S. degree in Nuclear Engineering from the same institution. Prof. Allain joined Argonne National Laboratory as a staff scientist in 2003 and joined the faculty in the School of Nuclear Engineering at Purdue University in Fall of 2007 with a courtesy appointment with the School of Materials Engineering.  Prof. Allain established breakthrough programs at Purdue University including in-situ characterization facilities as an Associate Professor in 2010.  Prof. Allain joined the faculty at the University of Illinois at Urbana-Champaign in the Department of Nuclear, Plasma, and Radiological Engineering in 2013 as an Associate Professor and recently promoted to Professor and named Professor of Technology Entrepreneurship.  He is an affiliate faculty with the Department of Bioengineering, the Micro and Nanotechnology Lab, the Beckman Institute for Advanced Science and Technology and the Technology Entrepreneurship Center.  Prof. Allain is the author of over 120 papers in both experimental and computational modeling work in the area of particle-surface interactions.  His research includes developing novel advanced self-healing and adaptive materials in both the solid and liquid state. Prof. Allain was recipient of numerous awards including the DOE Early Career 2010 Award, the Research Excellence Award in 2011, the Fulbright Award in 2015, The Faculty Entrepreneurial Fellow in 2016 and Dean’s Excellence in Research Award in 2017.