Low and high frequency instabilities in an explosion-generated-plasma and possibility of wave triplet

Abstract

An explosion-generated-plasma is explored for low and high frequency instabilities by taking into account the drift of all the plasma species together with the dust particles which are charged. The possibility of wave triplet is also discussed based on the solution of dispersion equation and synchronism conditions. High frequency instability (HFI) and low frequency instability (LFI) are found to occur in this system. LFI grows faster with the higher concentration of dust particles, whereas its growth rate goes down if the mass of the dust is higher. The ion and electron temperatures affect its growth in opposite manner and the electron temperature causes this instability to grow. In addition to the instabilities, a simple wave is also observed to propagate, whose velocity is larger for larger wave number, smaller mass of the dust and higher ion temperature.

High-frequency instabilities in an explosion-generated relativistic plasma

“…Hence, it can also be said that the wave propagating at higher speed evolves into an instability having larger growth rate. This is the similar result as obtained recently in a nonrelativistic EGP [33]. Consistent to Ref.…”

“…Consistent to Ref. 33, the present plasma also supports a propagating mode which has a constant velocity (Fig. 2).…”

“…Here, the electron temperature is found to reduce the growth rates of both the instabilities. This result is contrary to the observation made in an explosion-generated nonrelativistic plasma [33]. Hence, it appears that due to the relativistic effect of the ions and electrons, the thermal motions of the electrons start suppressing the growth of the instabilities.…”

“…However, in view of heavy mass of the dust particles, this is justified to consider them as nonrelativistic but to drift with a finite speed. Our earlier article [33] depicts an approximate situation, where we considered only the initial drifts of the plasma species. In view of the nonrelativistic situation, we had also neglected the temperature of the dust species.…”

Effect of dust on tilted electrostatic resistive instability in a Hall thruster

“…It is found that in the previous studies, dust particles have been neglected by the researchers, which become important plasma species in the Hall thrusters due to the erosion of the wall of the chamber and sputtering [22,23]. In general, it is found that current carried by the highly mobile electrons plays the important role in dust charging, and as a result, the dust particles are negatively charged in the plasma [24][25][26][27][28][29]. The & Hitendra K. Malik hkmalik@hotmail.com negatively charged dust particles will hinder the movement of ions and, hence, alter the thrust and efficiency of the thruster.…”