Dynamics of structure formation and self-organization in open systems

开放系统中结构形成和自组织的动力学

• 批准号: 13640414
• 负责人: HORIUCHI Ritoku
• 金额: $ 1.6万
• 依托单位: National Institute for Fusion Science
• 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 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13640414/
• 关键词: collisionless reconnection; open system; particle orbit effect; lower hybrid drift instability; drift-kink instability; external driving source; field-reversed configuration; tilting mode stabilization; 構想形成; 電磁粒子シミュレーション; 自己組織化; キンク不安定性; 傾斜モー

A. There are a steady regime and an intermittent regime in the temporal behavior of collisionless reconnection, dependently on the spatial profile of an external driving flow. The steady collisionless reconnection is realized in the case of small input window size, in which the reconnection rate is balanced with the flux input rate at the upstream boundary and the global dynamic process of magnetic reconnection is dominantly controlled by ion dynamics : As the window size increases, the current sheet becomes longer, which is favorable to the excitation of an electron tearing instability. The system evolves into an intermittent regime, in which magnetic islands are frequently generated in the current sheet. Two-scale structure is formed in the current density profile through combined actions of both ion and electron dynamics. Electron pressure tensor associated with electron meandering motion in the central electron current sheet is a main cause of generation of reconnection electric fi … More eld at neutral sheet in two-dimensional steady reconnection, although the evolution of the whole reconnection system is controlled mainly by an external condition.B. In three-dimensional case plasma instabilities are excited and affect the dynamical behavior of collisionless reconnection. In the presence of an external driving source the lower hybrid drift waves excited in the periphery propagate toward the neutral sheet and thus generate anomalous resistivity in the current sheet. Consequently, the external driving electric field penetrates into the current sheet and triggers magnetic reconnection at the neutral sheet. Magnetic islands are created in the downstream as a result of magnetic reconnection, but they become unstable against the kink instability. After magnetic islands disappear through the downstream boundary, the system relaxes into a quasi-steady state temporarily. An electromagnetic (EM) mode with a low-frequency comparable to ion gyration frequency (drift-kink instability) grows slowly in the current sheet and modifies the spatial structure.C. Self-generation process of hollow current profile and its influence on tilting instability in field-reversed configurations are investigated by means of two-dimensional and three-dimensional EM particle simulations. The system spontaneously relaxes from a magnetohydrodynamic equilibrium toward a kinetic one, in which the electron current profile becomes hollow. Growth rate of the tilting instability in the case of the hollow current profile and high separatrix beta value is smaller than that in the case of the peaked current profile. When magnetic separatrix shape is much prolate, the unstable region is localized near the edges, and stabilization of the tilt instability becomes effective. Less

A.无碰撞重连接的时间行为存在稳定状态和间歇状态，取决于外部驱动流的空间轮廓。稳定无碰撞重连接是在小输入窗口尺寸的情况下实现的，其中重连接率。与上游边界处的通量输入速率平衡，磁重联的全局动态过程主要由离子动力学控制：随着窗口尺寸的增加，电流片变得更长，这有利于电子撕裂的激发该系统演变为间歇状态，其中通过与电子蜿蜒相关的离子和电子压力张量的联合作用，在电流密度分布中经常产生磁岛。尽管整个重联系统的演化主要受外部条件控制，但中心电子电流片的运动是二维稳定重联中中性片重联电场产生的主要原因。维案例等离子体不稳定性被激发并影响无碰撞重连接的动力学行为。在存在外部驱动源的情况下，外围激发的较低混合漂移波向中性片传播，从而在所测试的电流片（外部驱动）中产生异常电阻率。电场穿透电流片并在中性片处触发磁重联，由于磁重联而在下游产生磁岛，但在磁岛通过磁岛消失后，它们变得不稳定。在下游边界，系统暂时松弛到准稳态，具有与离子回转频率相当的低频电磁（EM）模式（漂移扭结不稳定性）在电流片中缓慢增长并改变空间结构。通过二维和三维电磁粒子模拟研究了空心电流剖面的自生成过程及其对场反转配置中倾斜不稳定性的影响。系统自发地从磁流体动力学平衡松弛。一种动力学曲线，其中空心电流轮廓和高分界线β值的情况下的倾斜不稳定性的增长率小于当磁分界形状为峰值电流轮廓的情况下的倾斜不稳定性的增长率。长得太多，不稳定区域集中在边缘附近，并且倾斜不稳定的稳定效果较差。

项目成果

T.Hayashi, R.Horiuchi, K.Watanabe, T.Sato: "Outlook of Multiple Time and Spatial Scale Simulation for Understanding Self Organizing Phenomena in Plasmas."J.Plasma and Fusion Research. 79. 464-469 (2003)

T.Hayashi、R.Horiuchi、K.Watanabe、T.Sato：“用于理解等离子体中自组织现象的多时间和空间尺度模拟的展望。”J.等离子体与聚变研究。

R.Horiuchi, H.Ohtani, A.Ishizawa: "Structure formation and dynamical behavior of kinetic plasmas controlled by magnetic reconnection"Computer Physics Communications. (掲載決定). (2004)

R.Horiuchi、H.Ohtani、A.Ishizawa：“磁重联控制的动态等离子体的结构形成和动力学行为”计算机物理通讯（2004 年出版）。

H.Naito, T.Matsumoto, Y.Todo, R.Horiuchi: "Kinetic Effects on Magnetohydrodynamic Phenomena"J. of Plasma and Fusion Research. Vol.77. 547-556 (2001)

H.Naito、T.Matsumoto、Y.Todo、R.Horiuchi：“磁流体动力学现象的动力学效应”J。

T.Ishimori, T.Kaneko, S.Ishiguro, R.Hatakeyama, N.Sato: "Particle Simulation of Potential Formation Due to Local ECR along Diverging Magnetic-Field Lines"Journal of Plasma and Fusion Research. Vol.IV(掲載予定). (2002)

T.Ishimori、T.Kaneko、S.Ishiguro、R.Hatakeyama、N.Sato：“沿发散磁场线局部 ECR 的潜在形成的粒子模拟”等离子体与聚变研究杂志第 IV 卷（待定）。出版））（2002）。

Lj.Nikolic, M.M.Skoric, S.Ishiguro, T.Sato: "Stimulated electron-acoustic-wave scattering in a laser plasma"Physical Review E. Vol.66, No.3-2B. 036404-1-036404-4 (2002)

Lj.Nikolic、M.M.Skoric、S.Ishiguro、T.Sato：“激光等离子体中的受激电子声波散射”物理评论 E. 第 66 卷，第 3-2B 号。