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Experimental Study of Ion Species Separation in Multi-Component Plasma Shocks

多分量等离子体激波中离子形态分离的实验研究

基本信息

批准号：
1903442
负责人：
Colin Adams
金额：
$ 20万
依托单位：
Virginia Polytechnic Institute and State University
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2019
资助国家：
美国
起止时间：
2019-07-01 至 2023-06-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1903442&HistoricalAwards=false
关键词：
Experimental Study Ion Species Separation

项目摘要

Shock waves, frequently observed in air, also occur in high temperature gases where electrons have been liberated from ions, forming a plasma. This project will experimentally study shock waves by colliding plasma jets with stagnant plasma. When the plasma is composed of species of differing electric charge and mass, the rapid change in plasma properties across the shock wave can cause separation of these species, further complicating the shock structure. Understanding the physics present in these scenarios is important to furthering the understanding of astrophysical phenomena, including Type II supernova explosions, as well as the physics of implosions that occur in inertial-confinement fusion experiments. This project will collect detailed experimental data characterizing collisions between high-velocity multi-species plasma jets and stagnant plasma in an experiment where shock thickness is predicted to be large enough to be readily observable by diagnostic instruments.This project aims to experimentally identify shocks in multi-component plasmas in a parameter space where it is possible to resolve the structure of the ion shock layer. Interactions of collisional multi-species plasma jets with stagnated plasma will be studied in a regime where the mean-free-path is small enough for the jet interaction to be collisional yet large enough to attempt diagnosis of the shock structure over a few hundred mean-free-paths. The scope of the project will be to identify shocks formed during these interactions and investigate the parameter space to confirm whether the observed shocks are present in multi-ion-species plasmas. A series of multi-ion-species plasma jets will be emitted by a linear plasma-armature railgun. Shortly after the first jet stagnates against a barrier, the second jet will encounter the stagnant plasma at velocities sufficient to drive a shock in the plasma. A suite of diagnostics will be used to capture data indicating the presence of individual plasma species. The diagnostics that will be employed include (i) high spatial resolution survey spectroscopy to locate emission from ion species at the shock front and (ii) multi-chord interferometry which will be used in conjunction with spectroscopy to infer charge state and electron temperature in the shocked and unshocked regions. The experimental observations sought by this research have the potential to shed light on never-before-observed shock structures caused by collisional diffusion of ion species. This could enhance understanding of astrophysical phenomena and the physics of inertial fusion plasmas.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.

在空气中经常观察到的冲击波也发生在高温气体中，其中电子已经从离子中释放出来，形成等离子体。本项目将通过实验研究等离子体射流与停滞等离子体碰撞产生的冲击波。当等离子体由不同电荷和质量的物质组成时，冲击波中等离子体性质的快速变化可能导致这些物质分离，进一步使冲击波结构复杂化。理解这些场景中的物理学对于进一步理解天体物理现象非常重要，包括II型超新星爆炸，以及惯性约束聚变实验中发生的内爆物理学。该项目将收集详细的实验数据，描述高速多物种等离子体射流与停滞等离子体之间碰撞的特征，在实验中，预计激波厚度足够大，可以通过诊断仪器容易地观察到，该项目的目的是在参数空间中通过实验确定多组分等离子体中的激波，其中可以解析离子激波层的结构。碰撞的多物种等离子体射流与停滞等离子体的相互作用将在一个制度，其中的平均自由路径是足够小的射流相互作用是碰撞，但足够大，试图诊断的冲击波结构超过几百个平均自由路径的研究。该项目的范围将是确定在这些相互作用过程中形成的冲击，并调查参数空间，以确认所观察到的冲击是否存在于多离子种类等离子体中。线性等离子体电枢轨道炮将发射一系列多离子种类的等离子体射流。在第一射流停滞在障碍物上之后不久，第二射流将以足以驱动等离子体中的激波的速度遇到停滞的等离子体。将使用一套诊断程序来捕获指示存在单个血浆物质的数据。将采用的诊断方法包括：（一）高空间分辨率测量光谱法，以确定激波前沿离子物质的发射位置;（二）多弦干涉测量法，将与光谱法结合使用，以推断受冲击和未受冲击区域的电荷状态和电子温度。这项研究所寻求的实验观测有可能揭示以前从未观察到的离子物种碰撞扩散引起的激波结构。该奖项反映了NSF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。