Development of an Ultrafast Laser Instrument for Probing Earth and Planetary Materials under Extreme Pressures and Temperatures

为了解释地震异常、评价地球、S等行星的组成和动力学模型，需要了解地球和行星物质的弹性知识，而它们的输运性质(热导率和电导率)是控制核、地幔热历史及其动力学的关键参数。这些性质与行星的吸积和分异、地幔和地核温度的时间演化以及地球S磁场的产生有关。尽管最近取得了许多技术进展，但在极端条件下原位测量上述材料的性能仍然是一个具有挑战性的问题。该项目将开发新的、快速的、基于飞秒激光的仪器，用于在钻石顶锤单元(DAC)中原位测量承受极高压力和温度(P-T)的材料的弹性和传输特性(与热和能量有关的光学传导性)。该项目团队将采用现有的声学干涉测量(AI)和时间域热反射(TDTR)技术，以适应该研究小组开发的脉冲激光加热DAC技术。他们将设计和建造宽带光谱(BBOS)装置，该装置将允许使用超亮脉冲飞秒激光光源在从紫外线到中红外的高P-T条件下原位测量材料的光学性质。

Knowledge of elasticity of Earth and planetary materials is needed for interpretation of the seismic anomalies, evaluation of the Earth?s and other planets compositional and dynamical models, while their transport properties (thermal and electrical conductivity) are the key parameters controlling the thermal history of the core and mantle and their dynamics. These properties are related to the planetary accretion and differentiation, the time evolution of mantle and core temperatures, and the generation of the Earth?s magnetic field. In spite of numerous recent technical developments, in situ measurements of the above listed materials properties under extreme conditions remain a challenging problem. This project will develop new, fast, fs laser-based instrumentation for in situ measurements of elasticity and transport properties (thermal and energy dependent optical conductivity) of materials subjected to extreme high pressure and temperature (P-T) in the diamond anvil cell (DAC). The project team will adapt the existing acoustic interferometry (AI) and time-domain thermoreflectance (TDTR) techniques for the pulsed laser heated DAC technology developed by this research group. They will design and build a broadband spectroscopy (BBOS) setup, which will allow in situ measurement of material optical properties at high P-T conditions from ultraviolet to mid infrared using an ultra-bright pulsed fs laser source.