5:15 PM - 6:45 PM
[MIS18-P08] Nucleation experiment of carbon from gas phase in microgravity environment using a sounding rocket
Keywords:Nucleation, Dust, Sounding rocket
To understand formation processes of carbonaceous dust in a gas outflow from a carbon-rich evolved star, we have established an international team in a framework of Institute of Space and Astronautical Science (ISAS) Small-Scale Science Projects of the Japan Aerospace Exploration Agency (JAXA) after started a working team in ISAS/JAXA in 2016. In 2019, we performed a microgravity experiment using the sounding rocket of Swedish Space Corporation, MASER14, with a support of German Aerospace Center (DLR) and found a formation process of titanium carbide core-graphitic carbon mantle grain, which is one of most famous presolar grains [1]. This core-mantle grain forms through a multi-step nucleation process consisting of homogeneous nucleation of carbon, heterogeneous nucleation of titanium carbide, and fusion growth of nanoparticles over a wide Ti/C ratio. To clarify the universality of this process in more carbon-rich environments and to found formation processes of carbon dust, we are planning to do additional sounding rocket experiment planning to launch in Spring 2024.
During the microgravity condition, we generate a hot carbon vapor, which gradually cools and condensed far from thermal equilibrium [2]. Since there is no substrate/dust working as a heterogeneous nucleation site, carbon dust must be nucleated homogeneously. Using double-wavelength Mach-Zehnder interferometer, nucleation temperature and carbon concentration are determined. Using a latest nucleation model, two most important parameters, sticking probability and surface tension, to predict nucleation condition will be determined. In particular, the surface tension of carbon has been reported to have a very wide range of values from 0.04 to 4.8 N m-1 [3], which adds a large degree of uncertainty to the prediction of dust nucleation. In addition, the sticking probability may be several orders of magnitude smaller than previously thought [2]. Therefore, it is very important to obtain fundamental data to discuss the dust nucleation process based on nucleation experiments of carbon. If everything going well according to current plan, we will show the fresh data just obtained in one month.
[1] Y. Kimura, K. K. Tanaka, Y. Inatomi, C. Aktas, J. Blum, Nucleation experiments on a titanium–carbon system imply nonclassical formation of presolar grain, Science Advances, 9 (2023) eadd8295. DOI: 10.1126/sciadv.add8295
[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 (6pp). DOI: 10.1126/sciadv.1601992
[3] R. G. Tabak, J. P. Hirth, G. Mevrick, T. P. Roark, The nucleation and expulsion of carbon
particles formed in stellar atmospheres. The Astrophysical Journal. 196 (1975) 457–463. DOI:
10.1086/153425
Acknowledgements
Microgravity experiments were conducted with the technical support of the Swedish Space Corporation (SSC) with financial support from the DLR with funds provided by the Federal Ministry for Economic Affairs and Climate Action (BMWK), and ISAS, JAXA. Developments of the experimental system was supported by the Technical Division of Institute of Low Temperature Science, Hokkaido University, and the Advanced Machining Technology Group of JAXA. Onboard data saving was supported by Dr. S. Takeuchi of ISAS/JAXA. This work was supported by FY2016 ISAS Small-Scale Science Projects of JAXA and Grant-in-Aids for Scientific Research (S) from KAKENHI (15H05731 and 20H05657).
During the microgravity condition, we generate a hot carbon vapor, which gradually cools and condensed far from thermal equilibrium [2]. Since there is no substrate/dust working as a heterogeneous nucleation site, carbon dust must be nucleated homogeneously. Using double-wavelength Mach-Zehnder interferometer, nucleation temperature and carbon concentration are determined. Using a latest nucleation model, two most important parameters, sticking probability and surface tension, to predict nucleation condition will be determined. In particular, the surface tension of carbon has been reported to have a very wide range of values from 0.04 to 4.8 N m-1 [3], which adds a large degree of uncertainty to the prediction of dust nucleation. In addition, the sticking probability may be several orders of magnitude smaller than previously thought [2]. Therefore, it is very important to obtain fundamental data to discuss the dust nucleation process based on nucleation experiments of carbon. If everything going well according to current plan, we will show the fresh data just obtained in one month.
[1] Y. Kimura, K. K. Tanaka, Y. Inatomi, C. Aktas, J. Blum, Nucleation experiments on a titanium–carbon system imply nonclassical formation of presolar grain, Science Advances, 9 (2023) eadd8295. DOI: 10.1126/sciadv.add8295
[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 (6pp). DOI: 10.1126/sciadv.1601992
[3] R. G. Tabak, J. P. Hirth, G. Mevrick, T. P. Roark, The nucleation and expulsion of carbon
particles formed in stellar atmospheres. The Astrophysical Journal. 196 (1975) 457–463. DOI:
10.1086/153425
Acknowledgements
Microgravity experiments were conducted with the technical support of the Swedish Space Corporation (SSC) with financial support from the DLR with funds provided by the Federal Ministry for Economic Affairs and Climate Action (BMWK), and ISAS, JAXA. Developments of the experimental system was supported by the Technical Division of Institute of Low Temperature Science, Hokkaido University, and the Advanced Machining Technology Group of JAXA. Onboard data saving was supported by Dr. S. Takeuchi of ISAS/JAXA. This work was supported by FY2016 ISAS Small-Scale Science Projects of JAXA and Grant-in-Aids for Scientific Research (S) from KAKENHI (15H05731 and 20H05657).