Study of particle acceleration processes at collisionless shocks via next-generation and first-principle particle simulations

通过下一代和第一原理粒子模拟研究无碰撞冲击下的粒子加速过程

• 批准号: 21200050
• 负责人: UMEDA Takayuki
• 金额: $ 17.31万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research on Innovative Areas (Research a proposed research project)
• 财政年份: 2009
• 资助国家: 日本
• 起止时间: 2009 至 2011
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-21200050/
• 关键词: 宇宙線; 宇宙・天体プラズマ; 超高層物理学; 計算科学; 次世代スーパーコンピュータ; プラズマ; 計算物理

Large-scale two-dimensional full particle-in-cell simulations are carried out for studying non-stationarity of perpendicular shocks. It is confirmed that the persistence and absence of the self-reformation is controlled by micro-instabilities at the shock front. When electromagnetic whistler mode waves are strongly excited by the modified two-stream instability, both incoming and reflected ions are strongly scattered and the shock reformation becomes absent. On the other hand, when electrostatic waves are weakly excited or there is no micro-instabilities, reflected ions show a coherent behavior and the shock reformation is persistent. In this case, however, the reformation period is modified essentially due to the shock front ripples. The present simulation result suggests that the structure and dynamics of shocks are affected by the cross-scale coupling between electron-scale micro-instabilities and ion-scale shock-front ripples.

为了研究垂直激波的非平稳性，进行了大规模二维全颗粒细胞模拟。已证实，自重整的持续和缺失是由激波前沿的微观不稳定性控制的。当电磁哨声模式波被改进的双流不稳定性强烈激发时，入射离子和反射离子都被强烈散射，并且激波重组消失。另一方面，当静电波被弱激发或不存在微观不稳定性时，反射离子表现出相干行为，并且激波重组是持续的。然而，在这种情况下，重整周期基本上由于激波前沿波纹而被修改。目前的模拟结果表明，激波的结构和动力学受到电子尺度微观不稳定性和离子尺度激波前沿波纹之间的跨尺度耦合的影响。

项目成果

On the reformation at quasi- and exactly-perpendicular shocks: Full particle-in-cell simulations

关于准垂直和完全垂直冲击下的重组：完整的粒子内细胞模拟

• DOI: 10.1029/2010ja015458
• 发表时间: 2010
• 期刊: J. Geophys. Res.
• 作者: T. Umeda;Y. Kidani;M. Yamao;S. Matsukiyo;and R. Yamazaki
• 通讯作者: and R. Yamazaki

Modified two-stream instability at perpendicular shocks : Full particle simulations

修正垂直冲击下的两流不稳定性：完整粒子模拟

• 发表时间: 2011
• 作者: Y.Kidani;T.Umeda;S.Matsukiyo;T.Ogino
• 通讯作者: T.Ogino

垂直衝撃波の再形成に関する2次元全粒子シミュレーション

垂直冲击波重组的二维全粒子模拟

• 发表时间: 2011
• 作者: 木谷佳隆;梅田隆行;荻野竜樹;松清修一
• 通讯作者: 松清修一

Modified two-stream instability at perpendicular collisionless shocks: Full particle simulations

修正垂直无碰撞冲击下的两流不稳定性：完整粒子模拟

• DOI: 10.1029/2011ja017182
• 发表时间: 2012
• 期刊: J Geophys. Res.
• 作者: T. Umeda;Y. Kidani;S. Matsukiyo;and R. Yamazaki
• 通讯作者: and R. Yamazaki

Suppression of reflected electrons by kinetic Alfven turbulence in a quasi-perpendicular shock: Particle-in-cell simulations

准垂直激波中运动阿尔文湍流对反射电子的抑制：细胞内粒子模拟

• DOI: 10.1088/0004-637x/736/1/35
• 发表时间: 2011
• 期刊: Astrophys. J.
• 作者: Ishida;N.;S. Saito and T. Umeda
• 通讯作者: S. Saito and T. Umeda