Nonlinear Fluid and Kinetic Effects in Nonneutral Plasmas

该奖项支持等离子体中一系列基本非线性过程的实验、理论和模拟项目。这些研究将集中在能够得到理论的精确实验检验的问题上。实验将在非中性等离子体上进行，等离子体包含自由电子，离子和不带电物质的混合物，使用具有广泛操作制度和诊断的电子陷阱和离子陷阱。这些系统的简单性使得理论和实验之间的理解有了深度和精确的比较，这在其他情况下是不可能的。该奖项将支持一名研究生的培训，研究结果将广泛应用于自然和工程等离子体系统，包括用于发电的空间等离子体和聚变等离子体。该项目是一个非线性等离子体过程的综合研究，包括波-波相互作用；外加电场和磁场扰动引起的粒子、热量和动量输运；以及在波场和应用场中与非线性粒子捕获有关的效应。正在进行的实验已经观察到非线性波的不稳定性，其特征与波谷中非线性粒子脱陷和重陷的新动能粒子理论相一致。这些实验，以及伴随的理论和模拟，将被扩展，以便在其他波的背景下考虑这种捕获粒子机制，包括混合h -电子等离子体中的非中性离子声波和电子声波。在负离子-电子非中性等离子体上的新实验也将继续进行，使非线性过程在准中性等离子体和用于反氢生产的等离子体中具有重要意义。一个主要的焦点将是对流流体非线性效应与动力学捕获粒子非线性效应之间的相互作用。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。

This award supports a program of experiments, theory, and simulations on a range of fundamental nonlinear processes in plasmas. The studies will focus on problems for which precise experimental tests of theory can be obtained. Experiments will be performed on non-neutral plasmas, plasmas that contain a mixture of free electrons, ions, and uncharged species, using an electron trap and an ion trap with a broad range of operating regimes and diagnostics. The simplicity of these systems allows a depth of understanding and a precision of comparison between theory and experiment that is rarely possible otherwise. The award will support training of a graduate student, and results of the research will have broader applications to natural and engineered plasma systems, including space plasmas and fusion plasmas for power generation.The project is an integrated study of nonlinear plasma processes including wave-wave interactions; particle, heat, and momentum transport caused by applied electric and magnetic field perturbations; and effects associated with nonlinear particle trapping in both waves and applied fields. Ongoing experiments have observed nonlinear wave instabilities with features that are consistent with a new kinetic particle theory of nonlinear particle detrapping and retrapping in the wave troughs. These experiments, along with accompanying theory and simulations, will be extended in order to consider this trapped particle mechanism in the context of other waves, including nonneutral ion acoustic waves in mixed H-electron plasmas, and electron acoustic waves. New experiments on negative ion-electron nonneutral plasmas will also be pursued, making connections to nonlinear processes of importance in quasi-neutral plasmas and in plasmas used in anti-hydrogen production. A major focus will be on the interplay between effects of convective fluid nonlinearity versus kinetic trapped particle nonlinearity.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.