Theory of Nonlinear Waves in Hot Space Plasmas

热空间等离子体中的非线性波理论

• 批准号: PP/D002087/1
• 负责人: Michael Balikhin
• 金额: $ 22.13万
• 依托单位: University of Sheffield
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2006
• 资助国家: 英国
• 起止时间: 2006 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=PP%2FD002087%2F1
• 关键词: Theory; Nonlinear; Waves; Hot; Space

The plasma state of matter is highly abundant in the universe. Plasma dynamics play a fundamental role in many of the processes in the near geo-space environment, at the sun, in the solar system and in the vicinity of remote astrophysical objects such as supernova remnants, space jets, and pulsars. Often plasma in its natural environment is collisionless. In such plasmas the role of particle collisions in an ordinary gas is replaced by particle interactions with electric and magnetic structures and waves. Therefore a study of waves is vital for understanding of plasma processes. Hot or high beta plasma is the plasma in which thermal plasma pressure is comparable to or exceeds the magnetic field pressure. The theoretical description of hot plasmas is much more complicated in comparison to cold plasma. In spite of the profusion of collisionless plasmas in the universe the only place where comprehensive experimental studies of plasma under natural conditions can be conducted at present is the geo-space environment. It is known from experimental studies in the vicinity of Earth that regions with hot plasma (e.g. magnetosheath, ring current) are rich with large amplitude, nonlinear, low frequency waves. The rigorous description of such waves even using a linear approximation (which is only valid for cases of waves with infinitesimally small amplitude) represents a quite complicated problem. The main goal of the present proposal is to develop a general theory of nonlinear waves in hot, uniform and non-uniform plasmas, building on the success of the linear theory of low frequency waves in hot plasma previously developed in the framework of the PPARC grant PPA/G/S/2002/000094. Based on this theory, it is then possible to produce a set of tools that will simplify the identification of low frequency waves observed in satellite experiments. These tools will include calculations of wave parameters in realistic conditions that correspond to those observed experimentally in space plasma. This tool may then be applied to the identification of waves observed by current or future satellite missions such as Cluster or Venus Express. In addition, we will study the implications of the developed theory to processes involved in the acceleration of particles in the vicinity of remote astrophysical objects such a supernova remnants.

等离子体状态的物质在宇宙中非常丰富。等离子体动力学在近地球空间环境、太阳、太阳系和遥远天体（如超新星遗迹、空间喷流和超新星）附近的许多过程中发挥着重要作用。通常等离子体在其自然环境中是无碰撞的。在这样的等离子体中，普通气体中粒子碰撞的作用被粒子与电磁结构和波的相互作用所取代。因此，波的研究对于理解等离子体过程至关重要。热或高β等离子体是其中热等离子体压力与磁场压力相当或超过磁场压力的等离子体。与冷等离子体相比，热等离子体的理论描述要复杂得多。尽管宇宙中存在大量的无碰撞等离子体，但目前唯一能够在自然条件下对等离子体进行全面实验研究的地方是地球空间环境。从地球附近的实验研究中得知，具有热等离子体的区域（例如磁鞘、环电流）富含大振幅、非线性、低频波。这种波的严格描述，即使使用线性近似（这是唯一有效的情况下，波与无限小的振幅）代表了一个相当复杂的问题。本提案的主要目标是在PPARC赠款PPA/G/S/2002/000094的框架内，在先前开发的热等离子体中低频波线性理论的成功基础上，开发热、均匀和非均匀等离子体中非线性波的一般理论。根据这一理论，有可能产生一套工具，简化卫星实验中观测到的低频波的识别。这些工具将包括计算与在空间等离子体中通过实验观察到的波参数相对应的实际条件下的波参数。然后，该工具可以应用于识别当前或未来的卫星任务（如Cluster或Venus Express）所观察到的波。此外，我们还将研究所发展的理论对在遥远的天体（如超新星遗迹）附近粒子加速过程的影响。

项目成果

Non-Maxwellian effects in magnetosonic solitons

磁声孤子中的非麦克斯韦效应

• DOI: 10.1016/j.pss.2007.05.019
• 发表时间: 2007
• 期刊: Planetary and Space Science
• 影响因子: 2.4
• 作者: Pokhotelov O

Rankine-Hugoniot relations for shocks with demagnetized ions

退磁离子冲击的兰金-于格尼奥关系

• DOI: 10.1017/s0022377807006708
• 发表时间: 2008
• 期刊: Journal of Plasma Physics
• 影响因子: 2.5
• 作者: GEDALIN M

THEMIS observations of mirror structures: Magnetic holes and instability threshold

• DOI: 10.1029/2008gl036923
• 发表时间: 2009-02
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: M. Balikhin;R. Sagdeev;S. Walker;O. Pokhotelov;D. Sibeck;N. Beloff;G. Dudnikova

Mirror instability in space plasmas: Solitons and cnoidal waves

空间等离子体中的镜像不稳定性：孤子和椭圆曲线波

• DOI: 10.1063/1.3153553
• 发表时间: 2009
• 期刊: Physics of Plasmas
• 影响因子: 2.2
• 作者: Istomin Y

Generalization of the Harris current sheet model for non-relativistic, relativistic and pair plasmas

• DOI: 10.1017/s002237780800723x
• 发表时间: 2008-12
• 期刊: Journal of Plasma Physics
• 影响因子: 2.5
• 作者: M. Balikhin;M. Gedalin