Density of molten gadolinium oxide measured with the electrostatic levitation furnace in the International Space Station

Abstract

Density of gadolinium oxide in its liquid phase was measured using a containerless technique under microgravity environment in the International Space Station (ISS). An electrostatically levitated sample was melted using high power semiconductor lasers. Pictures of a molten spherical sample were analyzed and corresponding volumes were obtained as afunction of temperature. After weighing the returned sample mass, the density of the Gd2O3 was found to be 7240 kg/m3 at its melting temperature (Tm = 2693 K).

Densities of Liquid Tm2O3, Yb2O3, and Lu2O3 Measured by an Electrostatic Levitation Furnace Onboard the International Space Station

“…To validate and demonstrate the capability of thermophysical property measurements of molten oxides at extremely high temperatures, Ln 2 O 3 s have been selected as the main target of the ISS-ELF project. Densities of Gd 2 O 3 , Tb 2 O 3 , Ho 2 O 3 , and Er 2 O 3 were successfully measured from 2017 to 2019 and reported in earlier publications [20][21][22]. Subsequently, densities of Tm 2 O 3 , Yb 2 O 3 , and Lu 2 O 3 were measured in 2021.…”

“…A detailed description of the facility is found in earlier publications [19,20], but a summary is given here for completeness.…”

Measurements of Density of Liquid Oxides with an Aero-Acoustic Levitator

“…In Table 1 the density and thermal expansion coefficient values for liquid oxides measured in this work are listed together with four types of previously published density data: (i) measurements in aerodynamic levitator by Granier and Heurnault’s [ 59 ], Kohara et al [ 65 ], and Kondo et al [ 66 ]; (ii) measurements with the electrostatic levitator on board of International Space Station [ 36 , 37 ]; (iii) refinement from pair distribution function analysis (PDF) of synchrotron X-ray scattering [ 62 ]; (iv) ab initio molecular dynamic computations [ 60 , 63 ].…”

“…Density measurements for Gd 2 O 3 and Er 2 O 3 were recently performed by a Japanese group with an electrostatic levitator furnace (ELF) at the International Space Station (ISS) [ 35 , 36 , 37 ]. The electrostatic levitation in microgravity conditions ensures the absence of disturbances by acoustic waves or by gas flow, resulting in a perfectly spherical shape of the levitating droplet.…”

“…It culminated in the design of an electrostatic levitation furnace (ELF), which is currently in operation at the International Space Station [ 35 ]. The first results on the density of liquid Er 2 O 3 and Gd 2 O 3 were published in 2020 [ 36 , 37 ].…”