[P-PS10] [JJ] 太陽系における惑星物質の形成と進化

[PPS10-13] Fe-Ni-S融体の弾性特性から探る火星内部構造

★招待講演

*寺崎 英紀¹、下山 裕太¹、真木 まゆみ¹、黒川 冬華¹、浦川 啓²、西田 圭佑³、斉藤 龍之介¹、田窪 勇作¹、柴崎 裕樹⁴、坂巻 竜也⁴、町田 晃彦⁵、肥後 祐司⁶、近藤 忠¹ (1.大阪大学大学院理学研究科、2.岡山大学大学院自然科学研究科、3.東京大学大学院理学研究科、4.東北大学大学院理学研究科、5.量子科学技術研究開発機構、6.高輝度光科学研究センター)

キーワード：火星、中心核、液体、音速、密度

To give a constraint core composition and interior structures of terrestrial planets, elastic properties, such as sound velocity and density, of liquid Fe-light element alloys at high pressure are required together with geodesy observations. In this study, we have measured sound velocity and density of liquid Fe-Ni-S (S=17-30 at%) using ultrasonic pulse-echo and X-ray absorption methods combined with multianvil apparatus up to 14 GPa and studied the effects of pressure and sulfur content on the elastic properties.
Measured sound velocity (V_P) of liquid Fe-Ni-S increased non-linearly with pressure and its pressure dependence is well fitted by the Birch-Murnaghan equation of state. Obtained bulk modulus of liquid Fe-Ni-S decreases with increasing sulfur content. Based on these obtained properties, we will discuss estimated radius and sulfur content of Martian core by comparison with observed moment of inertia data of Mars.