Turbulence in Collisionless Astrophysical Plasmas

无碰撞天体物理等离子体中的湍流

• 批准号: 0812811
• 负责人: Eliot Quataert
• 金额: $ 32.86万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0812811&HistoricalAwards=false
• 关键词: Turbulence; Collisionless; Astrophysical; Plasmas

Astrophysical plasmas are rarely observed to be static. Instead theyvary strongly in both time and space, a phenomena known as turbulence.Such plasmas are also typically endowed with magnetic fields, justlike the Earth and the Sun. An understanding of turbulence inmagnetized plasmas (known as MHD turbulence) is thus required tounderstand a wide variety of astrophysical phenomena, from the solarwind in our solar system (and how the solar wind impacts Earth) torotating disks of gas falling into black holes (which produce some ofthe brightest sources of light in the Universe). Our proposedresearch is aimed at understanding the behavior of MHD turbulence onsmall scales where the energy is converted into heat.We propose to carry out large-scale numerical calculations of theproperties of MHD turbulence on small scales. These calculations willpredict observable properties of the turbulence that can be directlycompared to measurements in the solar wind, and ultimately tomeasurements in the laboratory on Earth. The same calculations willpredict how plasmas are heated when the energy contained in theturbulence is dissipated -- one of the major unsolved problems in ourunderstanding of turbulence. These results will be compared tomeasurements in the solar wind; they will also be used to predict thelight we see from plasma falling into black holes -- our primaryobservational window onto black holes in nature. More broadly, thecalculations proposed here will advance the state-of-the-art innumerical modeling of turbulence in magnetized plasmas and will haveimplications for a wide variety of laboratory, space, andastrophysical plasmas.

天体物理等离子体很少被观察到是静态的。 取而代之的是，它们在时间和空间上都强烈，这种现象称为湍流。通常也将磁场赋予磁场，正当地球和太阳。 因此，需要了解湍流陷入困境的等离子体（称为MHD湍流），需要从太阳系中的太阳系（以及太阳风能影响地球）的圆盘散落到黑色孔中（会产生黑色孔中的某些最明亮的源）。 我们提出的研究旨在了解MHD湍流Onsmall量表的行为，在该尺度上，能量被转化为热量。我们建议对小尺度上MHD湍流的大规模数值计算进行大规模的数值计算。 这些计算将预测可观察到的湍流的特性，可以直接与太阳风中的测量以及最终在地球实验室中进行的测量。 相同的计算将预测当扰动中包含的能量消散时如何加热等离子体 - 这是我们对湍流失望的主要未解决问题之一。 这些结果将在太阳风中进行比较。它们还将用于预测我们从等离子体落入黑色孔中看到的景象 - 我们的主要手持式窗口到自然界中的黑洞。 更广泛地说，这里提出的提议将推进磁化等离子体中湍流的最先进的建模，并将对各种实验室，空间，和腹部物理等离子体进行象征。