JOINT MAE-CER SEMINAR

Lithium for Fusion – What is Needed to make it Work

David Ruzic, University of Illinois at Urbana-Champaign
March 7, 2018, 11:00am - 12:00pm, EBU-II 479

ABSTRACT:

Lithium has great promise as a plasma-facing material for magnetic fusion devices. It is low-Z, but most importantly it absorbs hydrogen. If the divertor plate was covered in clean lithium, almost all the incident H flux would be absorbed. This is important, because then no cold hydrogen molecules would return to the plasma and cool the edge. If the entire volume of a fusion device could be used for actual fusion (instead of just the inner third) a fusion device could be many times smaller, and thus economically attractive.

The difficulty is that lithium melts at a low temperature, and is very chemically active. Also, the flux of H is so high that the top surface would saturate. To solve this the lithium must be molten and flowing. This talk will demonstrate such a system and describe how it has been used in linear plasma test stands and in actual tokamaks. The next problems to be addressed were the lithium’s stability. Results showing how to suppress splashing will also be shown. The final difficulty is how to remove the hydrogen from the flowing molten lithium and return it to the fusion device fast enough to keep the tritium inventory low. Recent work on this very problem will be shown for the first time in this seminar.

BIO:

David Neil Ruzic is the Abel Bliss Professor of Engineering and is in the Department of Nuclear, Plasma and Radiological Engineering at the University of Illinois at Urbana-Champaign where he joined the faculty in 1984 after receiving his PhD in Physics from Princeton University and post-doctoral work at the Princeton Plasma Physics Laboratory. His research centers on the interaction of plasmas with materials. Applications include magnetic fusion energy as well as microelectronic processing. Professor Ruzic has a passion for teaching, particularly about energy sources where he gets to blow something up in almost every class. That course is now available as a completely free MOOC (massively open on-line course) through Coursera called “Energy Environment and Everyday Life” https://www.coursera.org/learn/energy-environment-life. He is a Fellow of the American Nuclear Society, a Fellow of the American Vacuum Society, a Fellow of the American Physical Society, Scientific Director of the International Union of Vacuum Science and Technology (IUVSTA) and has served at Illinois as an Assistant Dean and as an Associate Vice President. He was awarded the “Plasma Prize” form the AVS in 2015. He has published over 200 referred journal papers, 2 books, and 6 book chapters and has been awarded 7 patents. He has produced 32 PhD students and 56 thesis MS students who are now working in industry, national laboratories or academia. His current group consists of 3 Post-Docs, 11 graduate students and 21 undergraduate research assistants.