none
碩士 === 國立中央大學 === 太空科學研究所 === 94 === Satellite observations have revealed that the thermal pressure of collisionless plasmas usually exhibits the gyrotropic form with two distinct pressure components. Based on the double-polytropic magnetohydrodynamic (MHD) model, Hau and Sonnerup (1993) have found...
| Main Authors: | , |
|---|---|
| Other Authors: | |
| Format: | Others |
| Language: | en_US |
| Published: |
2006
|
| Online Access: | http://ndltd.ncl.edu.tw/handle/35778239815770803509 |
| Summary: | 碩士 === 國立中央大學 === 太空科學研究所 === 94 === Satellite observations have revealed that the thermal pressure of collisionless plasmas usually exhibits the gyrotropic form with two distinct pressure components. Based on the double-polytropic magnetohydrodynamic (MHD) model, Hau and Sonnerup (1993) have found that the properties of MHD waves may greatly be modified by the pressure anisotropy. In this study, we extend the ideal double-polytropic MHD model to include the ion inertial terms arising from the Hall current as well the finite electron temperature for examining the properties of MHD waves. The dispersion relations are derived and the effects of the ion inertial terms on the fire-hose and mirror instabilities are examined. It is shown that for the electron temperature anisotropy of , the fire-hose instability is enhanced and the mirror instability is stabilized, but for the result is reverse. The originally stable MHD waves may even become unstable for sufficiently large electron temperature anisotropy.
|
|---|