The plasma temperature （or the kinetic pressure） anisotropy is an intrinsic characteristic of a collisionless magnetized plasma. In this paper, based on the two-fluid model, a dispersion equation of low-frequency ...The plasma temperature （or the kinetic pressure） anisotropy is an intrinsic characteristic of a collisionless magnetized plasma. In this paper, based on the two-fluid model, a dispersion equation of low-frequency （ω〈〈ωci, ωci the ion gyrofrequency） waves, including the plasma temperature anisotropy effect, is presented. We investigate the properties of low-frequency waves when the parallel temperature exceeds the perpendicular temperature, and especially their dependence on the propagation angle, pressure anisotropy, and energy closures. The results show that both the instable Alfven and slow modes are purely growing. The growth rate of the Alfven wave is not affected by the propagation angle or energy closures, while that of the slow wave depends sensitively on the propagation angle and energy closures as well as pressure anisotropy. The fast wave is always stable. We also show how to elaborate the symbolic calculation of the dispersion equation performed using Mathematica Notebook.展开更多
After the charge of heavy ions is considered, a Sagdeev equation is obtained for the solitary kinetic Alfven waves （SKAWs） in a low-β （me/mp 〈〈 β 〈〈 1 or mp〉〉 me 〉〉α ）, three-component （electrons, prot...After the charge of heavy ions is considered, a Sagdeev equation is obtained for the solitary kinetic Alfven waves （SKAWs） in a low-β （me/mp 〈〈 β 〈〈 1 or mp〉〉 me 〉〉α ）, three-component （electrons, protons, and highly charged heavy ions） plasma. Numerical results show that the charge number q of heavy ions can cause the width of the solitary structure to decrease, but increase for the maximum of electron density nem≤ 1.2 and the initial abundance of heavy ions Cbo≤ 0.1. The parallel phase speed of the waves increases with larger q.展开更多
基金supported by National Natural Science Foundation of China(Nos.10973043,41074107)Ministry of Science and Technology of China(No.2011CB811402)
文摘The plasma temperature （or the kinetic pressure） anisotropy is an intrinsic characteristic of a collisionless magnetized plasma. In this paper, based on the two-fluid model, a dispersion equation of low-frequency （ω〈〈ωci, ωci the ion gyrofrequency） waves, including the plasma temperature anisotropy effect, is presented. We investigate the properties of low-frequency waves when the parallel temperature exceeds the perpendicular temperature, and especially their dependence on the propagation angle, pressure anisotropy, and energy closures. The results show that both the instable Alfven and slow modes are purely growing. The growth rate of the Alfven wave is not affected by the propagation angle or energy closures, while that of the slow wave depends sensitively on the propagation angle and energy closures as well as pressure anisotropy. The fast wave is always stable. We also show how to elaborate the symbolic calculation of the dispersion equation performed using Mathematica Notebook.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10425312, 10373026, 40574065, and 10333030.
文摘After the charge of heavy ions is considered, a Sagdeev equation is obtained for the solitary kinetic Alfven waves （SKAWs） in a low-β （me/mp 〈〈 β 〈〈 1 or mp〉〉 me 〉〉α ）, three-component （electrons, protons, and highly charged heavy ions） plasma. Numerical results show that the charge number q of heavy ions can cause the width of the solitary structure to decrease, but increase for the maximum of electron density nem≤ 1.2 and the initial abundance of heavy ions Cbo≤ 0.1. The parallel phase speed of the waves increases with larger q.
