Effect of dust particle and magnetic field on EEPF and plasma oscillation

Abstract

The significance of dust particles for the electron energy probability function (EEPF) and plasma oscillations is studied under varying magnetic field strength in a filamentary discharge hydrogen plasma. The experimental result shows that with an increase in dust density, the electron density decreases as a result of the charging of dust grains in the plasma background. A bi-Maxwellian EEPF is computed in both a pristine hydrogen plasma and a dust-containing plasma at different magnetic field strengths. We have observed that the increase in magnetic field decreases the lower energy electron population. The electron population of the lower energy range shows nearly identical results at magnetic field, $B\leqslant 3.7$ mT whereas the behaviour of the high-energy electron population becomes identical for a field strength $B\leqslant 5.8$ mT. From the observation, we have seen that the mid energy electron population slightly decreases and the high energy electron population slightly increases due to the presence of dust particles as compared to a pristine plasma. Further, very low energy electron population remains almost unchanged. With increase in dust density, the mid energy electron population further decreases whereas the high energy electron population slightly increases for different magnetic fields. But, no changes were observed for the very low energy electron population in the presence of dust particles. From the study of plasma oscillation, it is observed that the dominant frequency associated with the plasma oscillation is matched with the ion cyclotron frequency. The amplitude of the ion cyclotron frequency reduces with the increase of dust density which might be due to the decrease of plasma density.

Determination and control of ion parameters in complex plasma of a DC discharge

“…The proposed scheme summarizes the analysis of numerous experimental results and simulations listed above. One of the main conclusions is that the axial electric field E z and the electron temperature both increase in a positive column with a dust cloud: these facts are confirmed by the results obtained in various gases under similar conditions [32][33][34][35][36][37][38][39][40]. Spectroscopic and probe measurements also confirm these effects [41][42][43].…”

Secondary electron emission and collisional effects in a two‐electron temperature plasma sheath

“…Recently, many experimental studies have reported the existence of non-Maxwellian electron distribution in processing plasmas as well as in edge plasmas of tokamaks. [18][19][20][21][22] Therefore, it becomes necessary to go for a more generalized approach that incorporates the effects of short as well as long-range particle interactions in plasmas. Such an approach has been recently put forward by Tsallis in the form of non-extensive entropy, given as [23]…”

“…Recently, many experimental studies have reported the existence of non‐Maxwellian electron distribution in processing plasmas as well as in edge plasmas of tokamaks. [ 18–22 ] Therefore, it becomes necessary to go for a more generalized approach that incorporates the effects of short as well as long‐range particle interactions in plasmas. Such an approach has been recently put forward by Tsallis in the form of non‐extensive entropy, given as [ 23 ] $$$$ {S}_q={k}_B\left(\frac{1-{\Sigma}_i{p}_i^q}{q-1}\right) $$$$ where $$$ {k}_B $$$ is the Boltzmann constant, $$$ {p}_i $$$ is the probability of $$$ {i}^{th} $$$ micro‐state and $$$ q $$$ is a real number denoting the measure of non‐extensivity of the system.…”