Abstract
Vlasov simulations of the current-driven ion-acoustic instability produced in Maxwellian and non-Maxwellian (Lorentzian, κ = 2) electron-ion plasma with number density 7 × 106 cm-3, reduced mass ratio mi/me = 25, and electron to ion temperature ratio T e/Ti = 1 are presented and compared. A concise stability analysis of current-driven ion-acoustic waves in Maxwellian and non-Maxwellian plasmas modeled by generalized Lorentzian distribution function with index 2 ≤ κ ≤ 7 and electron to ion temperature ratio 1 ≤ T e/Ti ≤ 100 is also presented. The ion-acoustic instability is excited in low temperature ratio Lorentzian (κ = 2) plasma for lower absolute electron drift velocity (up to half the critical electron drift velocity of a Maxwellian). The anomalous resistivity resulting from ion acoustic waves in a Lorentzian plasma is a strong function of the electron drift velocity and in the work presented here varies by a factor of ∼100 for a 1.5 increase in the electron drift velocity. Furthermore, ion-acoustic anomalous resistivity is excited for electron drift velocities that would be stable for Maxwellian plasmas. The magnitude of resistivity which can be generated by unstable ion-acoustic waves may be important for magnetic reconnection at the magnetopause.
Original language | English |
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Article number | 1442 |
Journal | Journal of Geophysical Research: Space Physics |
Volume | 108 |
Issue number | A12 |
DOIs | |
Publication status | Published - Dec 2003 |
Externally published | Yes |
Keywords
- Anomalous resistivity
- Ion-acoustic instability
- Lorentzian distribution
- Magnetic reconnection
- Wave-particle interactions