TEMPUS: Electromagnetic levitation in microgravity

Kurzfassung

Electromagnetic Levitation (EML) is a contactless processing technique, which enables the investigation of conductive samples over a broad temperature range even at temperatures below the melting point (undercooled state) [1]. The heart of the EML facility is a copper coil, which induces strong eddy currents inside the sample to heat and levitate the electronically conductive samples such as pure metals, alloy or semiconductors. A huge advantage is the contactless processing and temperature measurement of the levitating sample, which minimizes the sample contamination while processing the liquid sample at high temperatures well above the liquidus.

TEMPUS ('Tiegelfreies, elektomagnetisches Prozessieren unter Schwerelosigkeit' means in englisch Containerless electromagnetic processing in microgravity) [2] is a EML facility, which enables EML experiments in about 22 seconds microgravity onboard a parabolic flight. In microgravity, much weaker positioning fields are necessary, thus heating and positioning the sample can be decoupled. Consequently, the fluid flow in the liquid sample can be minimized or even be controlled during experimentation. Thus, TEMPUS allows for measuring thermophysical properties of high quality. Additionally, TEMPUS enables the investigation of solidification processes via different high-speed cameras as well as the post-flight analysis of the unique microstructure due to the microgravity environment.

[1] R.P. Liu, T. Volkmann, D.M. Herlach, "Undercooling and solidification of Si by electromagnetic levitation", Acta Materialia, pp. 439-444, 2001.

[2] G. Lohöfer, M. Beckers, T. Blumberg, D. Bräuer, S. Schneider, T. Volkmann and A. Meyer, "TEMPUS - A microgravity electromagnetic levitation facility for parabolic flights," Rev. Sci. Instrum., pp. 1-6, 2024.