Hybrid Particle Simulation of Parallel Fire-hose Instability

• Main Authors: Shau-Chin Su, 蘇韶晴
• Other Authors: 郝玲妮
• Format: Others
• Language: en_US
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/16222697598616592859

碩士 === 國立中央大學 === 太空科學研究所 === 95 === In a magnetized, collisionless plasma, the pressure or temperature is often anisotropic. The pressure anisotropy may lead to the instability; in particular, if the plasma satisfies the condition of P//>P⊥+B02/μ0, the fire-hose instability may occur. Past studies have shown that the evolution of fire-hose instability consists of two stages: the linear stage where the magnetic field fluctuation grows rapidly and the plasma is brought back to the marginal stability, and the second stage where the evolution becomes slower and the magnetic field fluctuation is reduced. The mechanism that drives the plasma back to the marginal instability however is still unclear. In this study we develop a hybrid particle code to simulate and analyze the detailed evolution of the fire-hose instability. It is found that the magnetic field fluctuations and the ion motions and the associated current flows are highly interacting with each other at the linear stage. At the saturation time the particle motions become chaotic because of the complicated gyro-motions and the magnetic field fluctuation gradually reduces; after that the coupling between the magnetic field and particle motions become less obvious.