Laboratory Simulation of Magnetized Plasma Turbulence in the Intergalactic Medium

星际介质中磁化等离子体湍流的实验室模拟

• 批准号: EP/M022331/1
• 负责人: Gianluca Gregori
• 金额: $ 102.9万
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FM022331%2F1
• 关键词: Laboratory; Simulation; Magnetized; Plasma; Turbulence

We propose an experimental programme to probe one of the greatest puzzles of modern astrophysics: the generation and amplification of magnetic fields ubiquitously found in the Universe. The aim is to demonstrate amplification of magnetic fields by turbulent dynamo - a great challenge of modern experimental plasma physics. We will also study the distribution of turbulent energy between velocity, magnetic and density fluctuations, providing a comprehensive experimental characterisation of the energy cascade in a turbulent plasma. Magnetic fields are ubiquitously observed in the Universe. Their energy density is comparable to the energy density of the mean plasma flows, so the magnetic fields are essential players in the dynamics of the luminous matter. The total magnetic energy represents a sizable fraction of the cosmic energy budget. What is the origin of these fields? The fact that they are ubiquitous, stochastic and dynamically strong suggests that a universal physical mechanism is at play. The most popular scenario of the cosmic magnetogenesis is that the field grows via some form of turbulent dynamo - fast (exponential) amplification of stochastic field by turbulent motions into which it is embedded, starting from an initial small seed. Understanding magnetogenesis is part of the broader challenge of understanding cosmic turbulence, and the way different form of energies (thermal, turbulent, magnetic) are partitioned on various scales.With the advent of high-power lasers, a new field of research has opened where, using simple scaling relations, astrophysical environments can be reproduced in the laboratory. The similarity is sufficiently close to make such experiments of high interest. Here we propose to establish an experimental platform using laser-produced plasmas where magnetic fields are produced and amplified by turbulence. In the turbulent plasma, small magnetic fields are initially generated by electrical currents resulting from mis-aligned density and temperature gradients - the so-called Biermann battery effect. By then characterizing the properties of such plasmas and the embedded magnetic fields, we intend to show that those tiny fields can be amplified to much larger values, and up to equipartition with the kinetic energy of the turbulent motions. We will use these experiments to measure the magnetic-energy, density and velocity spectra in the turbulent plasma, thus addressing the details of the energy cascade. Thus, our work would establish, for the first time experimentally, the soundness of the theoretical expectation that tiny seeds produced at protogalactic structures (~10^-21 G) can be amplified to observed dynamically significant values (~10^-6 G) in cosmologically short times.

我们提出了一个实验计划来探索现代天体物理学最大的谜题之一：宇宙中无处不在的磁场的产生和放大。其目的是演示湍流发电机对磁场的放大--这是现代实验等离子体物理学的一个巨大挑战。我们还将研究湍流能量在速度、磁场和密度涨落之间的分布，为湍流等离子体中的能量级联提供全面的实验表征。磁场在宇宙中随处可见。它们的能量密度与平均等离子体流的能量密度相当，所以磁场在发光物质的动力学中起着至关重要的作用。总磁能在宇宙能量预算中占了相当大的比例。这些油田的起源是什么？它们无处不在、随机且动态强大的事实表明，一种普遍的物理机制正在发挥作用。宇宙磁发生最流行的情景是，磁场从最初的小种子开始，通过随机磁场嵌入其中的湍流运动，通过某种形式的湍流快速(指数)放大随机场而增长。理解磁场发生是理解宇宙湍流的更广泛挑战的一部分，以及不同形式的能量(热、湍流、磁)在不同尺度上的划分方式。随着高功率激光的出现，一个新的研究领域已经打开，使用简单的尺度关系，可以在实验室中重现天体物理环境。这种相似性足以让人们对这样的实验产生浓厚的兴趣。在这里，我们建议建立一个实验平台，使用激光产生的等离子体，其中磁场是由湍流产生和放大的。在湍流等离子体中，小磁场最初是由密度和温度梯度不对准导致的电流产生的，即所谓的比尔曼电池效应。通过表征这种等离子体和嵌入的磁场的性质，我们打算证明，这些微小的磁场可以被放大到更大的值，并与湍流运动的动能等分。我们将利用这些实验测量湍流等离子体中的磁能、密度和速度谱，从而解决能量级联的细节问题。因此，我们的工作将首次在实验上确立理论预期的合理性，即在原星系结构(~10^-21G)中产生的微小种子可以在宇宙学的短时间内放大到动态观测到的有意义的值(~10^-6G)。

项目成果

Guiding of relativistic electron beams in dense matter by laser-driven magnetostatic fields.

• DOI: 10.1038/s41467-017-02641-7
• 发表时间: 2018-01-09
• 期刊: Nature communications
• 影响因子: 16.6
• 作者: Bailly-Grandvaux M;Santos JJ;Bellei C;Forestier-Colleoni P;Fujioka S;Giuffrida L;Honrubia JJ;Batani D;Bouillaud R;Chevrot M;Cross JE;Crowston R;Dorard S;Dubois JL;Ehret M;Gregori G;Hulin S;Kojima S;Loyez E;Marquès JR;Morace A;Nicolaï P;Roth M;Sakata S;Schaumann G;Serres F;Servel J;Tikhonchuk VT;Woolsey N;Zhang Z
• 通讯作者: Zhang Z

Insensitivity of a turbulent laser-plasma dynamo to initial conditions

湍流激光等离子体发电机对初始条件的不敏感性

• DOI: 10.1063/5.0084345
• 发表时间: 2022
• 期刊: Matter and Radiation at Extremes
• 影响因子: 5.1
• 作者: Bott, A. F.;Chen, L.;Tzeferacos, P.;Palmer, C. A.;Bell, A. R.;Bingham, R.;Birkel, A.;Froula, D. H.;Katz, J.;Kunz, M. W.
• 通讯作者: Kunz, M. W.

Triggering star formation: Experimental compression of a foam ball induced by Taylor-Sedov blast waves

触发恒星形成：由泰勒-谢多夫爆炸波引起的泡沫球的实验压缩

• DOI: 10.1063/5.0068689
• 发表时间: 2022
• 期刊: Matter and Radiation at Extremes
• 影响因子: 5.1
• 作者: Albertazzi B

Inefficient Magnetic-Field Amplification in Supersonic Laser-Plasma Turbulence

• DOI: 10.1103/physrevlett.127.175002
• 发表时间: 2021-10-21
• 期刊: PHYSICAL REVIEW LETTERS
• 影响因子: 8.6
• 作者: Bott, A. F. A.;Chen, L.;Casner, A.
• 通讯作者: Casner, A.

Proton imaging of stochastic magnetic fields

• DOI: 10.1017/s0022377817000939
• 发表时间: 2017-12-01
• 期刊: JOURNAL OF PLASMA PHYSICS
• 影响因子: 2.5
• 作者: Bott, A. F. A.;Graziani, C.;Schekochihin, A. A.
• 通讯作者: Schekochihin, A. A.