Specifications of a ground-based electrostatic levitation furnace and applications to the study of liquid properties

From 1997, the National Space Development Agency of Japan (NASDA) metastable research team has studied containerless materials processing to establish undercooled and nucleation processing techniques for oxides and high-melting-temperature metals as a preparation for flying the electrostatic levitation furnace on the International Space Station. This crucible-less facility allows samples to be deeply undercooled while avoiding nucleation on the sample surface. It allows not only precise measurements of the thermophysical properties of molten sample, but also permits material processing from the undercooled state. Of the four levitation techniques (acoustic, electromagnetic, electrostatic, aerodynamic), NASDA has concentrated on the development of an electrostatic levitation system, both for use in the ISS and for fundamental research on the ground. A promising containerless experiment of a ceramic oxide using the electrostatic containerless furnace under the microgravity condition offered by a sounding rocket (TR-IA No. 7) was also carried out in 1998 and is addressed in this paper. A novel aerodynamic levitation system was developed to adopt the drop tube which gave smooth cooling curves for molten Y₃Al₅O₁₂ (YAG) sample.