Laser Matter Interaction and Warm Dense Matter Science

我的研究计划侧重于对激光物质相互作用物理学及其应用的基本理解。我目前的重点是温暖的致密物质制度。暖密物质（WDM）是一种物质状态，由其可比的热能和费米能定义，并且密度使得离子之间的库仑势能超过它们的热动能。这是介于凝聚态和等离子体相之间的过渡区。WDM科学是极端条件下材料科学的一个领域，具有根本意义，因为它提供了凝聚态和等离子体物理之间的联系。WDM理论还没有得到很好的发展，它们对理论家提出了很大的挑战，因为WDM对于凝聚态理论来说太热了，而对于等离子体理论来说又太密集了。极端条件下材料的研究产生了巨大的科学兴趣，并被美国国家科学院确定为本世纪的优先研究领域。更好地了解WDM的定量细节对于激光材料加工、设计能够承受极端条件和惯性聚变能量的材料非常重要。* * 我们已经开发了一个实验平台，可以创建一个持续几皮秒的单态瞬态WDM。我们已经详细研究了它的性质实验探测它与超快探针，包括太赫兹，光学，X射线，和电子等。我们的光探测研究的交流导电性的温暖的致密金导致洞察其电子热容，电子离子结构的相互作用，和直流电导率。我们的超快电子衍射测量导致更好地理解金的超快熔化，并导致第一次观察到异质熔化向均匀熔化的过渡。我们开发了一种单次太赫兹探测技术，可以直接测量WDM的直流电导率。** 我们还开发了一种环形谐振腔技术来研究硅中的激光诱导损伤过程，并在孵化过程中获得了见解。我们计划将该技术扩展到其他半导体材料。我们还计划研究复杂材料的激光散射的基本物理过程，以支持我们在固体含量分析仪中用于拖尾管理和用于临床应用的无标记物理细胞术的应用研究。** 总之，我的研究计划的未来5年的主要目标是进一步了解热致密物质和激光诱导损伤机制，以影响激光聚变，聚变反应堆材料设计和激光材料加工。我们还希望获得对复杂材料的激光散射物理学的更好的基本理解，以支持我们在基于激光散射技术的几个应用中的研究。

My research program focuses in the fundamental understanding of laser matter interaction physics and several of its applications. My current focus is on the Warm Dense Matter regime. Warm Dense Matter (WDM) is a state of matter defined by its comparable thermal and Fermi energy, and a density such that the Coulomb potential energy between ions exceeds their thermal kinetic energy. This is a transition regime lying between the condensed matter and plasma phases. The WDM science, an area in material science under extreme conditions, is of fundamental significance because it provides a linkage between condensed matter and plasma physics. The WDM theories are not well developed and they present great challenge for theorists because WDM is too hot for condensed matter theories and too dense for plasma theories. The study of materials under extreme conditions has generated enormous scientific interest and was identified by the US National Academy of Sciences as a priority research area for this century. A better understanding of the quantitative details of WDM is important for laser materials processing, design of materials for withstanding extreme conditions and Inertial Fusion Energy.*** ***We have developed an experimental platform which can create a single state transient WDM lasts for several picosecond. We have studies its properties in details experimentally by probing it with ultrafast probes including THz, optical, xrays, and electrons etc. Our optical probing studies of AC conductivity of warm dense gold led to insights in its electron heat capacity, electron ion structure interaction, and DC conductivity. Our ultrafast electron diffraction measurement led to a better understanding of ultrafast melting of gold and led to the first observation of the transition of heterogeneous melting to homogeneous melting. We have developed a single shot THz probing technique which will measure the DC conductivity of WDM directly. ******We have also developed a ring resonator technique to study laser induced damage processes in silicon and obtained insights in the incubation processes. We plan to extend the technique to other semiconductor materials. We also plan to study the fundamental physical processes in laser light scattering of complex materials in support of our applied research in solid content analyzer for tailing management and label free physical cytometry for clinical applications. ******In summary the main goals for the next 5 years of my research program are to further the fundamental understanding of Warm Dense Matter and laser induced damage mechanisms to make impacts in laser fusion, fusion reactor materials design and laser materials processing. We also like to obtain a better fundamental understanding of the physics of laser light scattering of complex materials in support of our research in several applications based on the laser light scattering technique.***********