11:00 AM - 1:00 PM
[MIS12-P01] Preparation for nucleation experiment of ice nanoparticles by the low-temperature gas evaporation method
Keywords:nucleation, ice, microgravity
Water in the solar system forms as ice on dust in the cold environment (~10 K) of molecular clouds. Later, a warmer region (100-300 K) appears as a solar nebula and ice evaporates and recondenses depending on the temperature and pressure. While sublimation occurs in thermal equilibrium, condensation proceeds in a non-equilibrium process due to nucleation. Hence, it is difficult to theoretically predict the temperature and density conditions (on a spatial and temporal scale in the nebula) for the sublimated ice to cover the dust again. The primally objective of this study is to determine the physical quantities (surface free energy and sticking probability) essential for the theoretical prediction of recondensation of ice through nucleation experiments from the gas phase. This will allow us to estimate the surface minerals and surface area of dust in any given environment in the solar nebula. Accurate determination of the physical quantities requires experiments under microgravity conditions of the order of 0.0001G, which can be obtained with a sounding rocket [2]. Here, we report the results of a microgravity experiment using an airplane, which was conducted as a preliminary experiment for the purpose.
In laboratory, we have established a new experimental method for formation of ice nanoparticles using an originally designed nucleation chamber, the Advanced Laboratory Apparatus for Direct Detection of Ice Nucleation (ALADDIN) [1]. It has been designed to be able to cool the buffer gas inside the chamber using refrigerant (mainly liquid nitrogen). Water vapor generated from an evaporation source by resistive heating was cooled by buffer gas to a supersaturated, and then underwent homogeneous nucleation to form ice nanoparticles. The formation environment at the moments of homogeneous nucleation has been observed using a double-wavelength, Mach-Zehnder type laser interferometer. In this study, we developed a mini-ALADDIN for microgravity experiments using an aircraft.
Using the mini-ALADDIN, we succeeded in producing ice nanoparticles by the gas evaporation method for the first time under the microgravity environment. The gas evaporation method was developed in Japan triggered by a study of Ryogo Kubo, who predicted the significant properties of nanoparticles. Generally, the method has been applied to low volatility materials such as metals, oxides, and carbides. As a result of the microgravity experiment conducted in January 2022, we obtained essential data for the proposal of a sounding rocket experiment to elucidate the formation process of ice grains in space. In future, we aim to construct a nucleation model that can predict the state of ice dust that sublimated and condensed in the solar nebula 4.6 billion years ago.
[1] Y. Kimura, A. Kouchi, Preparation for nucleation experiment of ice nanoparticles by the low-temperature gas evaporation method, JpGU-AGU Joint Meeting 2020, MIS23-P04.
[2] Y. Kimura, K. K. Tanaka, T. Nozawa, S. Takeuchi, Y. Inatomi, Pure iron grains are rare in the universe, Science Advances, 3 (2017) e1601992. DOI: 10.1126/sciadv.1601992
Acknowledgements
Developments of the experimental system was supported by the Technical Division of Institute of Low Temperature Science, Hokkaido University. Microgravity experiments using an aircraft was operated by Diamond Air Service, Inc. This work was supported by committee of Space Environment Utilization of ISAS, JAXA and Grant-in-Aids for Scientific Research (S) from KAKENHI (15H05731 and 20H05657).
In laboratory, we have established a new experimental method for formation of ice nanoparticles using an originally designed nucleation chamber, the Advanced Laboratory Apparatus for Direct Detection of Ice Nucleation (ALADDIN) [1]. It has been designed to be able to cool the buffer gas inside the chamber using refrigerant (mainly liquid nitrogen). Water vapor generated from an evaporation source by resistive heating was cooled by buffer gas to a supersaturated, and then underwent homogeneous nucleation to form ice nanoparticles. The formation environment at the moments of homogeneous nucleation has been observed using a double-wavelength, Mach-Zehnder type laser interferometer. In this study, we developed a mini-ALADDIN for microgravity experiments using an aircraft.
Using the mini-ALADDIN, we succeeded in producing ice nanoparticles by the gas evaporation method for the first time under the microgravity environment. The gas evaporation method was developed in Japan triggered by a study of Ryogo Kubo, who predicted the significant properties of nanoparticles. Generally, the method has been applied to low volatility materials such as metals, oxides, and carbides. As a result of the microgravity experiment conducted in January 2022, we obtained essential data for the proposal of a sounding rocket experiment to elucidate the formation process of ice grains in space. In future, we aim to construct a nucleation model that can predict the state of ice dust that sublimated and condensed in the solar nebula 4.6 billion years ago.
[1] Y. Kimura, A. Kouchi, Preparation for nucleation experiment of ice nanoparticles by the low-temperature gas evaporation method, JpGU-AGU Joint Meeting 2020, MIS23-P04.
[2] Y. Kimura, K. K. Tanaka, T. Nozawa, S. Takeuchi, Y. Inatomi, Pure iron grains are rare in the universe, Science Advances, 3 (2017) e1601992. DOI: 10.1126/sciadv.1601992
Acknowledgements
Developments of the experimental system was supported by the Technical Division of Institute of Low Temperature Science, Hokkaido University. Microgravity experiments using an aircraft was operated by Diamond Air Service, Inc. This work was supported by committee of Space Environment Utilization of ISAS, JAXA and Grant-in-Aids for Scientific Research (S) from KAKENHI (15H05731 and 20H05657).