arXiv subjects

M. Salahuddin

Publications and source records attributed to M. Salahuddin.

3 recordsLinked to original sources

arXiv2021

Obliquely propagating ion-acoustic shock waves in degenerate quantum plasma

A theoretical investigation has been carried out on the propagation of nonlinear ion-acoustic shock waves (IASHWs) in a collsionless magnetized degenerate quantum plasma system composed of inertial non-relativistic positively charged light and heavy ions, inertialess ultra-relativistically degenerate electrons and positrons. The reductive perturbation method has been employed to drive the Burgers' equation. It has been observed that under consideration, our plasma model supports only positive potential shock structure. It is also found that the amplitude and steepness of the IASHWs have been significantly modified by the variation of ion kinematic viscosity, oblique angle, number density, and charge state of the plasma species. The results of our present investigation will be helpful for understanding the propagation of IASHWs in white dwarfs and neutron stars.

physics.plasm-ph↗

arXiv2021

Modulational instability of dust-ion-acoustic waves in pair-ion plasma having non-thermal non-extensive electrons

The modulational instability (MI) criteria of dust-ion-acoustic (DIA) waves (DIAWs) have been investigated in a four-component pair-ion plasma having inertial pair-ions, inertialess non-thermal non-extensive electrons, and immobile negatively charged massive dust grains. A nonlinear Schrödinger equation (NLSE) is derived by using reductive perturbation method. The nonlinear and dispersive coefficients of the NLSE can predict the modulationally stable and unstable parametric regimes of DIAWs and associated first and second order DIA rogue waves (DIARWs). The MI growth rate and the configuration of the DIARWs are examined, and it is found that the MI growth rate increases (decreases) with increasing the number density of the negatively charged dust grains in the presence (absence) of the negative ions. It is also observed that the amplitude and width of the DIARWs increase (decrease) with the negative (positive) ion mass. The implications of the results to laboratory and space plasmas are briefly discussed.

physics.plasm-ph↗

arXiv2018

Optimization of Neon Soft X-ray Emission in Low Energy Dense Plasma Focus Device

The Lee model code is used in numerical experiments for characterizing and optimizing neon soft X-ray (Ysxr) yield of UNU/ICTP PFF machine operated at 14 kV and 30 micro F. The neon Ysxr yield of the dense plasma focus device is enhanced by reducing static inductance (L0) and anode length (z0) along with increasing anode radius (a) and cathode radius (b), keeping their ratio (c = b/a) constant at 3.368. At the optimum combination of the electrodes geometry and static inductance, the maximum computed value of neon Ysxr yield is 63.61 J at operating pressure 3.3 Torr with corresponding X-ray yield efficiency 2.16%, while the end axial speed becomes 6.42 cm/s. This value of neon Ysxr yield is twelve to thirteen times higher than the measured value (5.4 J) at 3.0 Torr. It is also found that this neon Ysxr yield is improved around seven times from previously computed value (9.5 J) at 3.5 Torr for optimum anode configuration of this machine. Our obtained results of neon Ysxr yield are also compared with the computed results of AECS-PF2 machine operated at 15 kV and 25 micro F and is found that our results are about three times better than that from the optimized AECS-PF2 at L0 = 15 nH.

physics.plasm-ph↗