The stability of the kinetic Alfven wave (KAW) has been studied in a plasma composed of electrons, hydrogen and positively and negatively charged oxygen ions. Using the two potential theory of Hasegawa, we have derived an expression for the frequency and growth/damping rate of the KAW. The dispersion relation derived in this paper is a generalization of the dispersion relation of Hasegawa on two counts: (i) we use a more generalized distribution function and show that our relation reduces to the dispersion relation of Hasegawa in the limiting case, and (ii) it is applicable to a multi-ion plasma containing lighter ions and positively and negatively charged heavier ions. We find the growth rate of the wave increases with increasing drift velocities of the electrons. Negatively charged oxygen ions (O -) decrease the growth rate; however, the growth rate is very sensitively dependent on Oion density, especially when its density is greater than that of the positively charged oxygen ions (O + ). Interestingly, the dispersion characteristics of KAWs can be made insensitive to the presence of the heavier ions by an appropriate choice of their densities and temperatures.
Recent observation of oscillating the two stream instability (TSI) in a solar type III radio bursts and spatial damping of Langmuir oscillations has made this instability as an important candidate to understand the coronal heating problem. This instability has been studied by several authors for cold plasma found to be stable for high frequencies (greater than plasma frequency ω p ). In this paper, we prove that this instability is unstable for warm plasma for higher frequencies (greater than plasma frequency ω p ) and much suitable to study the solar coronal heating problem. We have derived a general dispersion relation for warm plasma and discussed the various methods analyzing the instability conditions. Also, we derived an expression for the growth rate of TSI and analyzed the growth rate for photospheric and coronal plasmas. A very promising result is that the ion temperature is the source of this instability and shifts the growth rate to high frequency region, while the electron temperature does the reverse. TSI shows a high growth rate for a wide frequency range for photosphere plasma, suggesting that the electron precipitation by magnetic reconnection current, acceleration by flares, may be source of TSI in the photosphere. But for corona, these waves are damped to accelerate the ions and further growing of such instability is prohibited due to the high conductivity in coronal plasma. The TSI is a common instability; the theory can be easily modifiable for multi-ion plasmas and will be a useful tool to analyze all the astrophysical problems and industrial devices, too.
Kappa distributions and with loss cone features have been frequently observed with flares emissions with the signatures of Lower hybrid waves. We have analysed the plasma with Kappa distributions and with loss cone features for the drift wave instabilities in perpendicular propagation for Large flare and Normal flare and Coronal condition . While analysing the growth/damping rate, we understand that the growth of propagation of EM waves increases with kappa distribution index for all the three cases. In comparing the propagation large flare shows lesser growth in compared with the normal and the coronal plasmas. When added the loss cone features to Kappa distributions, we find that the damping of EM wave propagation takes place. The damping rate EM waves is increases with T ⊥ T and loss cone index l, in all the three cases but damping is very high for large flare and then normal in comparision with coronal condition. This shows that the lower hybrid damping may be the source of coronal heating.
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