A modified Rayleigh-Taylor (RT) instability equation is derived using a three-fluid Hall thruster plasma model by including multi-ionized ions to study the growth rate of the RT instability. For a simplified plasma density and electron drift velocity axial profile, the growth rate for an unstable wave and the condition leading to this instability are discussed. A possible analytical solution for the modified Rayleigh-Taylor equation is discussed along with the condition that leads to it. For double-ionized ions, the behavior of growth rate and perturbed potential for different densities of double-ionized ions are studied. Manuscript profile

AbstractIn the present paper, we see the effect of shapes of perturbing pulses on the evolution of electromagnetic solitons in a plasma having nonrelativistic ions and electrons. For this, we make use of IMEX scheme in our simulations, which is an invariant scheme for the two-fluid plasma flow equations. In particular, the impact of ion-to-electron mass ratio, electron-to-ion temperature ratio and the width of perturbing pulse is examined on the phase velocity, peak amplitude and width of the solitons. Manuscript profile

AbstractThis paper presents a theoretical model for the generation of terahertz radiation by cosh-Gaussian laser beams of high intensity, which are capable of creating relativistic–ponderomotive nonlinearity. We find the components of the terahertz radiation for the relativistic laser plasma interaction, i.e. beating of the two lasers of same amplitude and different frequency in under dense plasma. We plot the electric field profile of the emitted radiation under the effect of lasers index. By creating a dip in peak of the incident lasers’ fields, we can achieve multifocal terahertz radiation. Manuscript profile

AbstractIn this study, a plasma-based low-temperature, low-pressure SiN film deposition is investigated for device applications. Ammonia, nitrogen and silane are being used for optimization of the quality of SiN film for device passivation by ICPCVD. Characterization of SiN film is done using elastic recoil detection analysis, AFM, FTIR and ellipsometry. The effect of previous process parameters on subsequent process is called memory effect, which has been investigated by all the characterization techniques. During deposition, this effect has been observed for the same parameters that are used to maintain the stoichiometry of the film. It has been observed that some of the residues of gases used for SiN deposition remain present even after the deposition in the chamber and are carried over for the next deposition process and alter the film property, though parameters such as flow rate, temperature, pressure and time remain fixed. This memory effect alters the film surface roughness and stoichiometry thus affecting device characteristics after passivation. Manuscript profile