Stability of electrostatic ion cyclotron waves in a multi-ion plasma

Pramana

G Renuka³  M J Kurian¹  Chandu Venugopal1¹  Molly Isaac²  S K Leju¹  S Jyothi¹ 

[1] School of Pure and Applied Physics, Mahatma Gandhi University, Priyadarshini Hills P.O., Kottayam 686 560, India$$;Department of Physics, All Saints’ College, Thiruvananthapuram 695 007, India$$;Department of Physics, University of Kerala, Thiruvananthapuram 695 581, India$$

关键词: Ion cyclotron waves;    multi-ions;    negative ions;    stability.;   

DOI  :  

学科分类：物理（综合）

来源: Indian Academy of Sciences

【 摘 要 】

We have studied the stability of the electrostatic ion cyclotron wave in a plasma consisting of isotropic hydrogen ions (𝐻+) and temperature-anisotropic positively (𝑂+) and negatively (𝑂−) charged oxygen ions, with the electrons drifting parallel to the magnetic field. Analytical expressions have been derived for the frequency and growth/damping rate of ion cyclotron waves around the first harmonic of both hydrogen and oxygen ion gyrofrequencies. We find that the frequencies and growth/damping rates are dependent on the densities and temperatures of all species of ions. A detailed numerical study, for parameters relevant to comet Halley, shows that the growth rate is dependent on the magnitude of the frequency. The ion cyclotron waves are driven by the electron drift parallel to the magnetic field; the temperature anisotropy of the oxygen ions only slightly enhance the growth rates for small values of temperature anisotropies. A simple explanation, in terms of wave exponentiation times, is offered for the absence of electrostatic ion cyclotron waves in the multi-ion plasma of comet Halley.

【 授权许可】

Unknown