A new experimental technique for studying mass transport in liquid metals

A new experimental technique was developed having general applicability to the study of a variety of mass transport effects in liquid metal alloys. This technique is based on the real-time monitoring of compositional changes at the outer diameter of a horizontally rotating bilayer melt tube through the use of isotope-excited X-ray fluorescence methods. The apparatus is described and applications to the measurement of interdiffusion coefficients as well as anomalous transport, involving the Rayleigh-Taylor instability, are discussed. Unlike prior methods for studying diffusion in liquid metals, the present technique eliminates uncertainties associated with solute redistribution during solidification. Another advantage is the ability to detect non-diffusive contributions to mass transport, in real time.