Effect of general loss-cone distribution function on electrostatic ion-cyclotron instability in an inhomogeneous plasma: particle aspect analysis |
| |
| Authors: | Ruchi Mishra M S Tiwari |
| |
| Institution: | (1) Department of Physics and Electronics, Dr. H. S. Gour University, Sagar, Madhya Pradesh, India, 470003 |
| |
| Abstract: | The electrostatic ion-cyclotron instability (EICI) in low β (ratio of plasma to magnetic pressure), anisotropic, inhomogeneous
plasma is studied by investigating the trajectories of the particles using the general loss-cone distribution function (Dory-Guest-Harris
type) for the plasma ions. In particular, the role of the loss-cone feature as determined by the loss-cone indices, in driving
the drift-cyclotron loss-cone (DCLC) instability is analysed. It is found that for both long and short wavelength DCLC mode
the loss-cone indices and the perpendicular thermal velocity affect the dispersion equation and the growth rate of the wave
by virtue of their occurrence in the temperature anisotropy. The dispersion relation for the DCLC mode derived here using
the particle aspect analysis approach and the general loss-cone distribution function considers the ion diamagnetic drift
and also includes the effects of the parallel propagation and the ion temperature anisotropy. It is also found that the diamagnetic
drift velocity due to the density gradient of the plasma ions in the presence of the general loss-cone distribution acts as
a source of free energy for the wave and leads to the generation of the DCLC instability with enhanced growth rate. The particle
aspect analysis approach used to study the EICI in inhomogeneous plasma gives a fairly good explanation for the particle energisation,
wave emission by the wave–particle interaction and the results obtained using this particle aspect analysis approach are in
agreement with the previous theoretical findings using the kinetic approach. |
| |
| Keywords: | Electrostatic ion-cyclotron instability Auroral acceleration region Inhomogeneous plasma Drift cyclotron loss-cone instability Loss-cone distribution function |
| 本文献已被 SpringerLink 等数据库收录！ |
|
