Ultracold Neutral Plasmas as High Energy Density Plasma Simulators

超冷中性等离子体作为高能量密度等离子体模拟器

• 批准号: 2009999
• 负责人: Scott Bergeson
• 金额: $ 50.94万
• 依托单位: Brigham Young University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-06-01 至 2024-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2009999&HistoricalAwards=false
• 关键词: Ultracold; Neutral; Plasmas; Energy; Density

This project will advance fundamental understanding of how ion temperatures change during violent collisions. Extremely powerful lasers have been built in the US and elsewhere to create small, controlled nuclear reactions. These lasers are tightly focused to heat atoms to temperatures of millions of degrees and force them to collide violently. Understanding exactly how this process works is critical for optimizing future experiments in laser-driven nuclear reactions. This project will reproduce violent ion collisions in slow-motion in an experiment where the ion motion can be measured with extreme precision. In collaboration with theory specialists, the results will be used to validate computer simulations. These simulations, in turn, can then be applied to higher temperature laser-driven experiments with greater confidence. In addition to this important scientific contribution, this project will allow undergraduate and graduate students to participate in cutting-edge research in the field of plasma science.The plasma generated in laser-driven high energy density (HED) experiments changes rapidly. The plasma is formed when a coated cryogenic solid deuterium-tritium fuel target is heated and compressed by laser energy. The plasma temperature rises from nearly absolute zero to millions of degrees and the density rises above solid-state density. Modeling collisions throughout this process requires many different approximations, complicating computer simulations of the rapidly changing environment. Experimental measurements of the electron and ion temperature and density are also challenging in such HED plasmas, due to both the violent physical conditions and the intensive modeling required to convert measured quantities into basic plasma properties. With appropriate temperature- and density-scaling, this research project will probe collision dynamics in some of these difficult-to-model and difficult-to-measure circumstances. The project will study energy transfer, radiative heating, and thermal relaxation in the strongly-coupled-plasma regime, over a range of initial densities and temperatures and for a few different geometries. The first task will be to measure momentum transfer and collisional heating in a dual-species ultracold neutral plasma. The second task will be aimed at measuring electron-ion energy relaxation in magnetized and unmagnetized ultracold neutral plasmas. ​Graduate and undergraduate students will be recruited and trained to work on the experiments.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.

这个项目将促进对猛烈碰撞期间离子温度如何变化的基本理解。美国和其他地方已经建造了极其强大的激光，以创造小型、可控的核反应。这些激光器被紧密聚焦，将原子加热到数百万度的温度，并迫使它们猛烈碰撞。准确地了解这一过程是如何工作的，对于优化未来激光驱动核反应的实验至关重要。这个项目将在一个可以极其精确地测量离子运动的实验中，以慢动作重现猛烈的离子碰撞。在与理论专家的合作下，结果将用于验证计算机模拟。反过来，这些模拟可以更有把握地应用于更高温度的激光驱动实验。除了这一重要的科学贡献外，该项目还将允许本科生和研究生参与等离子体科学领域的前沿研究。激光驱动高能量密度(HED)实验中产生的等离子体变化迅速。等离子体是在涂覆的低温固体氚燃料靶被激光能量加热和压缩时形成的。等离子体温度从几乎绝对零度上升到数百万度，密度上升到固态密度以上。在整个过程中对碰撞进行建模需要许多不同的近似，这使得对快速变化的环境的计算机模拟变得复杂。在这样的HED等离子体中，电子和离子的温度和密度的实验测量也是具有挑战性的，因为将测量量转换为基本的等离子体性质需要激烈的物理条件和密集的建模。通过适当的温度和密度标度，这项研究项目将在一些难以建模和难以测量的情况下探索碰撞动力学。该项目将研究强耦合等离子体区域中的能量传递、辐射加热和热弛豫，研究范围为初始密度和温度，以及几个不同的几何形状。第一个任务将是测量双组份超冷中性等离子体中的动量转移和碰撞加热。第二项任务是测量磁化和非磁化超冷中性等离子体中的电子-离子能量弛豫。​的研究生和本科生将被招募和培训来从事实验工作。这一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智力优势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

Ultracold neutral plasma expansion in a strong uniform magnetic field

强均匀磁场中的超冷中性等离子体膨胀

• DOI: 10.1103/physreve.105.045201
• 发表时间: 2022
• 期刊: Physical Review E
• 影响因子: 2.4
• 作者: Sprenkle, R. Tucker;Bergeson, S. D.;Silvestri, Luciano G.;Murillo, Michael S.
• 通讯作者: Murillo, Michael S.

Improved ionization potential of calcium using frequency-comb-based Rydberg spectroscopy

• DOI: 10.1103/physreva.106.062818
• 发表时间: 2022-11
• 期刊: Physical Review A
• 影响因子: 2.9
• 作者: C.R. Pak;Matthew Schlitters;S. Bergeson

Transport in non-ideal, multi-species plasmas

非理想、多物种等离子体中的传输

• DOI: 10.1063/5.0048227
• 发表时间: 2021
• 期刊: Physics of Plasmas
• 影响因子: 2.2
• 作者: Stanton, Liam G.;Bergeson, Scott D.;Murillo, Michael S.
• 通讯作者: Murillo, Michael S.

Relaxation of strongly coupled binary ionic mixtures in the coupled mode regime

耦合模式状态下强耦合二元离子混合物的弛豫

• DOI: 10.1063/5.0048030
• 发表时间: 2021
• 期刊: Physics of Plasmas
• 影响因子: 2.2
• 作者: Silvestri, Luciano G.;Sprenkle, R. Tucker;Bergeson, Scott D.;Murillo, Michael S.
• 通讯作者: Murillo, Michael S.