Thermal conductivity of Deep Earth's materials studied by combined fast pulsed laser and optical spectroscopy techniques

通过快速脉冲激光和光谱技术相结合研究地球深部材料的热导率

• 批准号: 1763287
• 负责人: Alexander Goncharov
• 金额: $ 28万
• 依托单位: Carnegie Institution of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-04-15 至 2021-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1763287&HistoricalAwards=false
• 关键词: Thermal; conductivity; Deep; Earth; materials

Knowledge of thermal conductivity of the Earth's mantle and core materials under extreme conditions is important for understanding the physical and chemical processes and their evolution in the Earth. Sustained heat transport through the mantle is crucial for the existence and stability of the Earth's magnetic field. The Earth's mantle dynamics depends on the rate of heat transfer by convection, conduction, and radiation, and understanding these processes requires knowledge on the conductive and radiative parts of thermal conductivity. The investigators will conduct measurements of the conductive and radiative parts of thermal conductivity at extreme conditions of pressure and temperature that are relevant for the Earth's deep interior. The laser techniques developed in this work will advance other fields, which benefit from knowledge of thermal conductivity under extremes, for example various energy applications. A range of students, including area high school students, undergraduates, graduate students, and postdoctoral associates, will benefit from high-quality scientific training at Carnegie that will be provided by participation in the cutting-edge science that will be developed in the course of this work. The investigators will determine the thermal conductivity of the Earth's key minerals under high pressure and high temperature conditions (up to 150 GPa and 6000 K) by using pump-probe pulsed laser techniques. To determine the lattice thermal conductivity, they will measure the heat flux histories across the sample using time- and spatially- resolved spectroradiometry and/or time-domain thermoreflectance. To infer the radiative thermal conductivity, the team will study the optical spectra of these mantle minerals in the ultraviolet-to-infrared spectral range. They will apply the time-resolved emission and optical broad band spectroscopy tools that they have previously developed including pulsed white laser (supercontinuum) in combination with time-resolved multichannel detectors (streak camera and intensified CCD). The experiments will be performed on Fe and Fe-rich alloys, high-quality geologically relevant samples pre-synthesized at high P-T condition in large-volume devices (e.g. single crystals of bridgmanite), silicate and oxide melts, and planetary ices. These high P-T experimental data will enable a direct estimate of the radiative and conduction parts of the thermal conductivity of the Earth's mantle and core. These measurements will elucidate complex laws which govern thermal conductivity in the deep interior and reach sufficient accuracy to critically improve existing planetary models.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

了解极端条件下地幔和地核材料的导热性对于理解地球的物理和化学过程及其演化是非常重要的。通过地幔的持续热传输对地球磁场的存在和稳定至关重要。地幔动力学取决于对流、传导和辐射的传热速率，理解这些过程需要了解导热性的传导和辐射部分。研究人员将在与地球深处有关的极端压力和温度条件下，对热导率的传导和辐射部分进行测量。在这项工作中开发的激光技术将推动其他领域的发展，这些领域受益于极端情况下的导热性知识，例如各种能源应用。一系列学生，包括地区高中生、本科生、研究生和博士后助理，将受益于卡内基高质量的科学培训，这些培训将通过参与这项工作过程中发展的尖端科学来提供。研究人员将利用泵浦探测脉冲激光技术确定地球关键矿物在高压和高温条件下（高达150 GPa和6000 K）的热导率。为了确定晶格热导率，他们将使用时间和空间分辨光谱辐射测量和/或时域热反射来测量样品的热通量历史。为了推断辐射热导率，研究小组将研究这些地幔矿物在紫外到红外光谱范围内的光谱。他们将应用他们之前开发的时间分辨发射和光学宽带光谱工具，包括脉冲白色激光（超连续介质）与时间分辨多通道探测器（条纹相机和增强CCD）相结合。实验将在铁和富铁合金、高P-T条件下在大体积装置中预合成的高质量地质相关样品（如桥菱石单晶）、硅酸盐和氧化物熔体以及行星冰上进行。这些高P-T实验数据将使我们能够直接估计地幔和地核的热导率的辐射和传导部分。这些测量将阐明控制深层内部热导率的复杂规律，并达到足够的精度，以严格改进现有的行星模型。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Radiative thermal conductivity of single-crystal bridgmanite at the core-mantle boundary with implications for thermal evolution of the Earth

核幔边界处单晶桥锰矿的辐射热导率对地球热演化的影响

• DOI: 10.1016/j.epsl.2021.117329
• 发表时间: 2022
• 期刊: Earth and Planetary Science Letters
• 影响因子: 5.3
• 作者: Murakami Motohiko;Goncharov Alexander F.;Miyajima Nobuyoshi;Yamazaki Daisuke;Holtgrewe Nicholas
• 通讯作者: Holtgrewe Nicholas

Raman spectroscopy on hydrogenated graphene under high pressure

• DOI: 10.1016/j.carbon.2019.09.077
• 发表时间: 2020-01-01
• 期刊: CARBON
• 影响因子: 10.9
• 作者: Pakornchote, Teerachote;Geballe, Zachary M.;Goncharov, Alexander F.
• 通讯作者: Goncharov, Alexander F.

Helium-hydrogen immiscibility at high pressures

高压下氦-氢不混溶

• DOI: 10.1063/1.5086270
• 发表时间: 2019
• 期刊: The Journal of Chemical Physics
• 作者: Yu Wang;Xiao Zhang;Shuqing Jiang;Zachary M. Geballe;Teerachote Pakornchote;Maddury Somayazulu;Vitali B. Prakapenka;Eran Greenberg;Alex;er F. Goncharov
• 通讯作者: er F. Goncharov

Thermal conductivity near the bottom of the Earth's lower mantle: Measurements of pyrolite up to 120 GPa and 2500 K

• DOI: 10.1016/j.epsl.2020.116161
• 发表时间: 2020-04
• 期刊: Earth and Planetary Science Letters
• 影响因子: 5.3
• 作者: Z. Geballe;N. Sime;J. Badro;P. V. van Keken;A. Goncharov

Intermolecular coupling and fluxional behavior of hydrogen in phase IV

• DOI: 10.1073/pnas.1916385116
• 发表时间: 2019-12-17
• 期刊: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• 影响因子: 11.1
• 作者: Goncharov, Alexander F.;Chuvashova, Irina;Mao, Ho-Kwang
• 通讯作者: Mao, Ho-Kwang