Simulation study on structure formation due to ion cyclotron instabilities

离子回旋不稳定性导致结构形成的模拟研究

• 批准号: 12680485
• 负责人: ISHIGURO Seiji
• 金额: $ 1.86万
• 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: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12680485/
• 关键词: aurora; particle acceleration; potential structure; double layer; anomalous resistivity; V-shaped potential structure; ionsphere; electrostatic ion-cyclotron instability; 異常低抗; イオンサイクロトロン; 沿磁力線電位差

Aurora is generated by ionization of oxygen and nitrogen molecules due to collision of high speed electrons which are accelerated along magnetic field lines in the ionosphere. In order to investigate the generation mechanism of these high speed electrons, we had developed self-consisted open-boundary two and a half dimensional electrostatic particle simulation code and had succeeded in demonstrating that the V-shaped dc potential structure is created by current-driven electrostatic ion-cyclotron instability. We have performed several simulation runs to investigate attained potential difference and potential structure dependencies on the system length and the width of the current layer. It is found that the attained potential difference increases with an increase in the simulation system. This result suggests that one can get several kV potential differences for several thousand-kilometer anomalous resistivity length. This is consistent with the auroral acceleration. The width of potential structure is almost equal to the width of the current layer. Furthermore, simulation runs have been performed by choosing simulation parameters such that both of electrostatic ion-cyclotron wave and ion acoustic wave are unstable. It has been shown that the ion cyclotron wave is dominant in this situation.

极光是由于高速电子在电离层中沿磁力线加速碰撞而导致氧和氮分子电离而产生的。为了研究这些高速电子的产生机制，我们开发了自组成的开边界二维半静电粒子模拟程序，并成功地证明了V型直流电势结构是由电流驱动的静电离子回旋不稳定性产生的。我们已经进行了几次模拟运行，以研究获得的潜在差异和潜在的结构对系统长度和当前层宽度的依赖关系。结果表明，所获得的电势差随模拟系统的增大而增大。这一结果表明，对于几千公里的异常电阻率长度，可以得到几个千伏的电位差。这与极光加速是一致的。潜在结构的宽度几乎等于当前层的宽度。此外，通过选择模拟参数使静电离子回旋波和离子声波都不稳定，进行了模拟运行。结果表明，在这种情况下，离子回旋波占主导地位。

项目成果

T. Kaneko, S. Ishiguro, R. Hatakeyama, and N. Sato: "Fine Structure of Plasma Potential Formed by Local ECR in a Magnetic-Mirror Field"Proceedings of the 2000 International Congress on Plasma Physics. 648-651 (2000)

T. Kaneko、S. Ishiguro、R. Hatakeyama 和 N. Sato：“磁镜场中局域 ECR 形成的等离子体势的精细结构”2000 年国际等离子体物理学大会论文集。

Lj. Nikolic, M. M. Skoric, S. Ishiguro, and 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。

Y.Todo: "Fokker-Planck simulation study of Alfven eigenmode bursts"Nuclear Fusio. 41・9. 1153-1159 (2001)

Y.Todo：“阿尔芬本征模爆发的福克-普朗克模拟研究”核聚变41・9（2001）。

T. Kaneko, R. Hatakeyama, N. Sato, and S. Ishiguro: "Plasma Confining Potential Self-Consistently Formed by Local Electron Cyclotron Resonance in a Well-Shaped Magnetic Field"Physics of Plasmas. Vol.9, No.4. 1271-1276 (2002)

T. Kaneko、R. Hatakeyama、N. Sato 和 S. Ishiguro：“在形状良好的磁场中由局域电子回旋共振自洽形成的等离子体限制势”等离子体物理学。

T. Ishimori, T. Kaneko, S. Ishiguro and N. Sato: "Particle Simulation of Potential Formation Due to Local ECR along Diverging Magnetic-Field Lines"JPFR Series. Vol.IV. 345-348 (2002)

T. Ishimori、T. Kaneko、S. Ishiguro 和 N. Sato：“沿发散磁场线局部 ECR 导致的潜在形成的粒子模拟”JPFR 系列。