Particle transport in space plasma : beyond the quasi-linear theories

空间等离子体中的粒子输运：超越准线性理论

• 批准号: 13640452
• 负责人: HADA Tohru
• 金额: $ 2.11万
• 依托单位: Kyushu University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13640452/
• 关键词: particle diffusion; particle acceleration; super; sub-diffusion; MHD turbulence; phase coherence; Levy process; 非線形波動; 超拡散・準拡散; 準線形理論; レビ過程

Diffusive transport of charged particles in a collisionless plasma is one of the central issues in space plasma research. Most of the conventional arguments are based on a classical diffusion model, a second order linear diffusion equation with a prescribed diffusion coefficient. However, recent progress in spacecraft observations as well as numerical simulation studies imply that several essential modifications are necessary to the model. In particular, the use of the Levy statistics appears to be quite useful, in which the transport properties have explicit dependence to relevant spatial and temporal scales. This is a direct consequence of that (1)the observed MHD turbulence in space has large amplitude and (2)the MHD waves have finite phase coherence. In this research project we evaluated various transport coefficients of energetic particles in MHD turbulence by performing numerical simulations (mainly test particle simulations), and related the diffusion properties to statistics of the turbulence. The presence of finite phase correlation among the MHD waves make the transport properties drastically deviate from quasi-linear predictions.

带电粒子在无碰撞等离子体中的扩散输运是空间等离子体研究的中心问题之一。大多数传统的论点都是基于经典的扩散模型，即具有给定扩散系数的二阶线性扩散方程。然而，航天器观测和数值模拟研究的最新进展表明，有必要对该模型进行几项必要的修改。特别是，Levy统计量的使用似乎非常有用，其中输运性质与相关的空间和时间尺度有明确的依赖关系。这是一个直接的结果：(1)空间中观测到的MHD湍流具有很大的振幅；(2)MHD波具有有限的相位相干性。在本研究项目中，我们通过数值模拟(主要是测试粒子模拟)评估了高能粒子在MHD湍流中的各种输运系数，并将扩散特性与湍流的统计特性进行了关联。MHD波之间的有限位相关联的存在使得输运性质大大偏离准线性预测。

项目成果

F.Otsuka, T.Hada: "Cross field diffusion of cosmic rays in a two-dimensional magnetic field turbulence"Space Sci.Rev.. 107(1-2). 499-502 (2003)

F.Otsuka、T.Hada：“二维磁场湍流中宇宙射线的交叉场扩散”Space Sci.Rev.107(1-2)。

F.Otsuka, T.Hada: "Cross field diffusion of cosmic rays : dependence on 2-d field turbulence models"proc to the 11th int'l congress on plasma physics. ICPP2002. 808-811 (2002)

F.Otsuka、T.Hada：“宇宙射线的跨场扩散：对二维场湍流模型的依赖”，第 11 届国际等离子体物理学大会议程。

B.T.Tsurutani, L.D.Zhang, G.L.Mason, G.S.Lakhina, T.Hada, J.K.Arballo, R.D.Zwidkl: "Particle transport in He-3-rich events : wave-particle interactions and particle anisotropy measurements"Annales Geophysicae. 20. 427-444 (2002)

B.T.Tsurutani、L.D.Zhang、G.L.Mason、G.S.Lakhina、T.Hada、J.K.Arballo、R.D.Zwidkl：“富含 He-3 事件中的粒子输运：波粒相互作用和粒子各向异性测量”地球物理学年鉴。

T.Hada, F.Otsuka, Y.Kuramitsu, B.T.Tsurutani: "Pitch angle diffusion of energetic particles by large amplitude MHD waves"roc.28th Int'l Cosmic Ray Conf.. 3709-3712 (2003)

T.Hada、F.Otsuka、Y.Kuramitsu、B.T.Tsurutani：“大振幅 MHD 波对高能粒子的俯仰角扩散”roc.28th Intl Cosmic Ray Conf.. 3709-3712 (2003)

G.Hada, F.Otsuka, Y.Kuramitsu, B.T.Tsurutani: "Pitch angle diffusion of energetic particles by large amplitude MHD waves"Proc.28th Int'l Cosmic Ray Conf.. 3709-3712 (2003)

G.Hada、F.Otsuka、Y.Kuramitsu、B.T.Tsurutani：“大振幅 MHD 波对高能粒子的俯仰角扩散”Proc.28th Intl Cosmic Ray Conf.. 3709-3712 (2003)