Plasma interactions with the ITER material mix

Matthew Baldwin, UC San Diego, PISCES Laboratory

February 10, 2016, 11:00am - 12:00pm, EBUII 479

Abstract:  In the next generation fusion reactor ITER, which is to commence plasma operations in 2020, two very different materials are chosen to be in contact with the plasma.  The edge plasma interacts with beryllium tile, while diverted ionization characterized by more extreme heat and particle loads, will terminate on castellated refractory tungsten.  The divertor will operate at high temperature (up to/above  ~1000 K) and experience high-fluxes of particles of deuterium and tritium (fuel), He (ash), and erosion from the Be first-wall.  Here tungsten is a good engineering choice because of its low sputter yield by these species, a high melt point, good thermal properties, and low T retention.  In the case of the first-wall, the less superior material beryllium, chosen for other reasons, suffices because the wall will not operate under conditions as extreme as the divertor.  The discussion will focus on the plasma materials interaction of these two materials, and experimental research at UCSD that is designed to examine materials response to hydrogen-isotope-rich fusion-relevant plasma environment.  The effects of He on the two materials, and also the formation of mixed materials of the Be-W system, caused by plasma erosion and deposition, will also be discussed.

Bio:  Dr. Baldwin received his PhD in physics from the University of New England, Australia, in 1997 for research on the creation of advance material-surface properties utilizing plasmas.  Following his PhD award, Dr. Baldwin spent 18 months lecturing on physics and electronics before taking up a position with the UCSD PISCES Laboratory, where he is currently a senior member of the research staff.  Since joining UCSD, Dr. Baldwin has engaged in plasma materials interaction research on numerous candidate materials considered for the nuclear fusion plasma material boundary, and most recently has concentrated on the ITER environment.