Abstract:
In this thesis, we have discussed lineariandinon-linear effectskonkdust acousticiwaves
(DAWs) inia magnetized electronegative dusty plasma. By electronegative dusty plasma,
we mean the plasmaihaving electrons, positive ions, negative ions, and dust particulates
constituents. In theilinear analysisiregime, initheiabsence of dusticharge fluctuations,
the Doppler’s frequency and growth rate are our main focus. The Doppler’s frequency
variation has been discussed with the effects of Cairns distributed positive ions, obliqueness
of the magnetic field, densityiratio of electrons versus energetic positive ions, and
normalized dust cyclotron frequency or magnitude of the magnetic field. It was found
that for dust acoustic waves these parameters affect the Doppler’s frequency. Similarly,
the growth rate variations have been discussed with the effects of Cairns distributed
positive ions, obliqueness of the magnetic field, normalized dust cyclotron frequency,
density ratio of electrons versus energetic positive ions, and density ratio of negative
ions versus energetic positive ions. It was observed that for dust acoustic waves these
parameters affect the growth rate. While in the same regime we also considered the
dust charge fluctuation and derived a linear expression.
Onithe otherihand, inithe non-lineariregime, DAWs have been investigated. Since we
are studying the low-frequency wave, therefore, we have to enlarge the space and time
coordinates by stretching the coordinates. By using the Reductive Perturbation Technique
(RPT), the Korteweg-de Vries Burger equation isiderived for theismall butifinite
amplitudeinon-linear dust acoustic wave (DAWs) bearing non-thermality (Cairns distributed)
in the positive ions. In our case, the non-linear KdVB equation in the absence
of the dust charge fluctuation, the dissipative term vanishes, and the non-linear KdVB
equation is reduced to the KdV equation which admits solitary wave solution. While
