2022 Fiscal Year Annual Research Report
Demonstration of impact coalescence process of silicate particles in photo-planetary disks
Publicly Offered Research
| Project Area | A Paradigm Shift by a New Integrated Theory of Star Formation: Exploring the Expanding Frontier of Habitable Planetary Systems in Our Galaxy |
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| Project/Area Number |
21H00052
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| Research Institution | University of Occupational and Environmental Health, Japan |
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Principal Investigator |
門野 敏彦 産業医科大学, 医学部, 教授 (60359198)
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| Project Period (FY) |
2021-04-01 – 2023-03-31
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| Keywords | 微粒子の高速衝突 / デブリ円盤 / サイズ分布 / 衝突による粒子の合体と破壊 / スペクトルエネルギー分布 |
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| Outline of Annual Research Achievements |
Impact experiments were conducted at a velocity of ~0.2-1.0 km/s using fine particles with several microns or sub-microns in size. For metal (Cu) plate targets, as previous impact experiments using projectiles with larger sizes than tens of micron, our experiments with the fine particles show that projectile materials can remain in the crater. For brittle (SiO2 glass) plate targets, though previous impact experiments using projectiles with larger sizes than tens of microns have shown the spallation and ejection of projectile materials, our experiments with the fine particles show that irreversible inelastic deformation of targets occurred like metals and that projectile materials can remain in the crater. This is explained by the absorption of impact energy determined via the competition between deformation and crack propagation. The deformation thus contributes to the energy absorption even for brittle materials at small sizes. Compiling our results and previous data, we found that sticking can occur in collisions with particles up to at least 1 cm for ductile (metal) targets and 10 microns for brittle targets at several hundred m/s. As an application, we evaluated the size distribution of dust grains in a debris disk where the sticking of fine particles is assumed to occur. We demonstrated that the collisional sticking modified the size distribution, resulting in the decrease of spectral energy distribution at millimeter wavelengths, consistent with the photometry data of this debris disk. This suggests that the sticking of fine particles occurs in this debris disk.
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| Research Progress Status |
令和4年度が最終年度であるため、記入しない。
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| Strategy for Future Research Activity |
令和4年度が最終年度であるため、記入しない。
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