Experimental study on melting at ultrahigh pressures with intense laser for Earth science and laser fusion

2014 Fiscal Year Final Research Report

• Project/Area Number: 23340175
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Plasma science
• Research Institution: Osaka University
• Principal Investigator: SHIGEMORI Keisuke 大阪大学, レーザーエネルギー学研究センタ, 准教授 (50335395)
• Co-Investigator(Kenkyū-buntansha): SAKAIYA Tatsuhiro 大阪大学, 理学研究科, 助教 (60452421) ; KONDO Tadashi 大阪大学, 理学研究科, 教授 (20252223) ; NAKAI Mitsuo 大阪大学, レーザーエネルギー学研究センター, 教授 (70201663)
• Project Period (FY): 2011-04-01 – 2015-03-31
• Keywords: 高強度レーザー / 超高圧力 / 音速 / 鉄合金 / ダイヤモンド / 融解

Outline of Final Research Achievements

This experimental study is to melting phenomena at ultrahigh pressures with intense laser. In inertial confinement fusion, hydrodynamic instabilities are of great importance for high density compression. In order to mitigate these instabilities, we focus on stiffness on target material. Experiments were carried out to explore melting issues on ultrahigh pressure region with x-ray radiography technique. We found that the melting at ultrahigh-pressure is "simple" melting from diamond structure into liquid phase. Also found that the stiffness of diamond can mitigate the initial imprinting with its low compressibility.
The melting issue at ultrahigh pressures are also of great important on Earth science. We carried out measurements of sound velocity of iron and iron mixture in order to determine the effects on composition of outer core of the Earth. We obtained the experimental data, suggesting the sound velocity shows good agreements with Birch's low at ultrahigh pressure up to 1 TPa.

Free Research Field

高エネルギー密度科学