Theoretical study of explosvie collapse mechanism in high-temperature plasmas by using a variational approach to multi-scale dynamical system

2015 Fiscal Year Final Research Report

• Project/Area Number: 25800308
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Plasma science
• Research Institution: Tohoku University
• Principal Investigator: HIROTA Makoto 東北大学, 流体科学研究所, 助教 (40432900)
• Research Collaborator: Morrison Philip J. University of Texas at Austin, Professor ; HATTORI Yuji 東北大学, 流体科学研究所, 教授 (70261469)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 二流体プラズマ / 磁気リコネクション / 爆発的不安定性 / 変分原理

Outline of Final Research Achievements

A mechanism for explosive magnetic reconnection in high-temperature plasma is investigated by analyzing the nonlinear evolution of a tearing instability in a two-fluid model that includes the effects of electron inertia and temperature. A high-resolution simulation of this model shows an explosive tendency for the nonlinear growth, where it is newly found that the explosive widening of the X-shaped current layer occurs locally around the reconnection point. The reason for the onset of this locally enhanced reconnection is explained theoretically by developing a novel nonlinear variational method. The theoretical model proves that the local reconnection can release the magnetic energy more efficiently than the global one and the estimated scaling of the explosive growth rate agrees well with the simulation results.

Free Research Field

電磁流体力学、流体力学、安定性理論