CAREER: Transport Phenomena in Ultracold Neutral Plasmas

这个教师早期职业发展（CAREER）计划奖支持超冷中性等离子体的传输特性的基本理论研究。超冷等离子体是一种新的物质状态，因为低温导致组成粒子，电子和离子，强烈耦合。这种介质与传统的等离子体具有根本不同的性质，类似于液体与气体的不同之处。强耦合等离子体出现在影响能源，安全和基础物理研究的几个学科。例子包括在惯性约束聚变实验中发现的致密等离子体、强激光-材料相互作用研究、声致发光微泡以及白色矮星和巨行星内部等天体。超冷等离子体提供了一个独特的窗口来观察这种物理现象，因为它们可以使用激光精确测量。这使得理论模型的详细测试成为可能。除了理论研究外，一个免费的推广计划将通过互动的“什么是等离子体”演示向公众介绍等离子体物理学。这将是爱荷华州大学（UI）空间科学史大型展览的一个组成部分，该展览将由UI自然历史博物馆展出，随后将作为UI移动的博物馆的巡回展览。超冷等离子体是由激光诱导的超冷原子电离形成的，导致冷离子和电子的电荷中性混合物。该项目提供的进展是统计力学理论和分子动力学模拟能够占两个组成部分的等离子体。这个相对较新的领域的理论和模拟都集中在单组分模型上，将等离子体视为单一流体。新的进展解决了双组分物理学，随着实验努力降低温度，这将变得越来越重要。将强调的特定过程是状态方程，相互扩散，粘度和能量弛豫速率。该项目将侧重于了解各种微观物理过程如何影响宏观传输，包括电子和离子电荷的相反符号，电子和离子的非平衡性质以及等离子体的动态介电响应。这些结果将为强耦合等离子体的基础物理学提供见解，有助于几个前沿研究领域。

This Faculty Early Career Development (CAREER) Program award supports a fundamental theoretical investigation of the transport properties of ultracold neutral plasmas. Ultracold plasmas are a novel state of matter because the low temperature causes constituent particles, electrons and ions, to be strongly coupled. This medium has fundamentally different properties than traditional plasmas, analogous to the ways in which liquids differ from gases. Strongly coupled plasmas arise in several disciplines influencing energy, security and fundamental physics research. Examples include dense plasmas found in inertial confinement fusion experiments, intense laser-material interaction studies, sonoluminescing microbubbles, as well as astrophysical objects such as white dwarfs and giant planet interiors. Ultracold plasmas provide a unique window to view this physics because they can be accurately measured using lasers. This enables detailed tests of theoretical models. In addition to the theoretical research, a complimentary outreach program will introduce the public to plasma physics through an interactive "What is Plasma" demonstration. This will be an integral part of a larger exhibit on the history of space science at the University of Iowa (UI) to be displayed by the UI Natural History Museum, and later as a traveling exhibit in the UI Mobile Museum. Ultracold plasmas are formed by laser-induced ionization of trapped ultracold atoms, resulting in a charge-neutral mixture of cold ions and electrons. Advances provided by this project are statistical mechanical theory and molecular dynamics simulations capable of accounting for both components of the plasma. Theory and simulations in this relatively new field have focused on one-component models, treating the plasma as a single fluid. The new advances address two-component physics that will become increasingly important as experiments strive for lower temperatures. The particular processes that will be emphasized are equation of state, mutual diffusion, viscosity and energy relaxation rates. The project will focus on understanding how various microphysics processes affect macroscopic transport, including the opposite sign of electron and ion charge, the nonequilibrium nature of electrons and ions, and the dynamic dielectric response of the plasma. The results will provide insights into the fundamental physics of strongly coupled plasmas, contributing to several frontier research fields.