Design of an experimental facility to study convection in liquid lithium

Abstract

Liquid lithium has been proposed as a possible material for both the first wall and the divertor/limiter of a fusion device. Recent experiments on the CDX-U device show that lithium can absorb a surface heat flux of greater than 40(MW/m2) with negligible evaporation. Observation of a focused electron beam hitting solid lithium in the CDX-U lithium tray saw melting of a large section and induced flows. It is believed that these flows redistributed the incident power flux. This paper presents the design of an experiment which will diagnose the flows induced by an intense heat flux onto a lithium pool and measure the maximum heat flux lithium can absorb with applied magnetic fields. A simplified analytical treatment of the expected fluid flow magnitude with increasing magnetic field and surface thermal gradient is shown. Experimental results of the system electron beam source are also shown. These results are the first step in the creation of an experimental facility to study the heat transfer capabilities of free-surface liquid lithium at the University of Illinois.