First results of the liquid lithium film experiment (LiLiFEx)

A facility to study condensation of lithium vapor in surfaces with temperatures above the melting point has been designed and constructed at CICATA Queretaro in Mexico. It is specifically designed to study Li vapor condensation on downward facing surfaces, where gravity is a destabilizing force and the condensate liquid film is subject to Rayleigh-Taylor instability, can lead to different condensation regimes such as filmwise or drop-wise condensation. This problem has been extensively studied for common industrial applications, but very little information is available for vapors of alkali metals, and lithium in particular. The lithium vapor is generated by a thermal evaporator, and the condensing surface is at a temperature above melting point (180 °C), so the condensed phase will be liquid. An IR camera looking into the substrate through a ZnSe window allows monitoring its temperature, so initial estimates of the condensation rate as well as the condensation mechanisms can be obtained from both the visual inspection and the changes in heat removal from the substrate. The effect of the type of surface and its surface finish on the condensation mechanics can also be studied in the facility.