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Roy K.,Beluti M. K. M. High School | Chatterjee P.,Siksha Bhavana Visva Bharati | Roychoudhury R.,Siksha Bhavana Visva Bharati
Physics of Plasmas | Year: 2014

The head-on collision and overtaking collision of four solitons in a plasma comprising superthermal electrons, cold ions, and Boltzmann distributed positrons are investigated using the extended Poincare-Lighthill-Kuo (PLK) together with Hirota's method. PLK method yields two separate Korteweg-de Vries (KdV) equations where solitons obtained from any KdV equation move along a direction opposite to that of solitons obtained from the other KdV equation, While Hirota's method gives multi-soliton solution for each KdV equation all of which move along the same direction where the fastest moving soliton eventually overtakes the other ones. We have considered here two soliton solutions obtained from Hirota's method. Phase shifts acquired by each soliton due to both head-on collision and overtaking collision are calculated analytically. © 2014 AIP Publishing LLC.

Roy K.,Siksha Bhavana Visva Bharati | Saha T.,Siksha Bhavana Visva Bharati | Chatterjee P.,Siksha Bhavana Visva Bharati
Astrophysics and Space Science | Year: 2012

Dust acoustic double layers are studied in a four component dusty plasma comprising positively and negatively charged dust grains, Boltzmann distributed ions and kappa distributed electrons. The conditions for existence of double layers are studied in detail using Sagdeev's method. Large amplitude double layers are obtained for a range of values of the plasma parameters. © 2012 Springer Science+Business Media B.V.

Mandal P.K.,Siksha Bhavana Visva Bharati | Ghosh U.N.,Siksha Bhavana Visva Bharati | Chaterjee P.,Siksha Bhavana Visva Bharati
Earth, Moon and Planets | Year: 2015

The nonlinear wave structures of ion acoustic waves in magnetized plasma comprising ions, non-extensive distributed electrons and kinematic viscosity are investigated through dynamical study. In a bounded cylindrical geometry Zakharov–Kuznestov–Burger (ZKB) equation is derived, for the first time, using reductive perturbation technic. System of coupled nonlinear ordinary differential equations is derived from ZKB equation and is solved numerically using fourth order Runge–kutta method. Equilibrium points are obtained and the features are studied dynamically in the neighbourhood of these points. With the variation of the non-extensive parameter and the kinematic viscosity parameter some important features in the nonlinear waves like oscillatory shocks to steady state propagation and vis-a-vis steady state propagation to oscillatory shocks emerge. When the values of the non-extensive parameter decrease, the phase portrait of the system shows that the change from stable spiral to stable closed and stable to unstable equilibrium happens. When the effect of dissipative term i.e. kinematic viscosity is considered some other significant features also evolve.The reduction of the value of kinematic viscosity results the change in nature of the waves from oscillatory shocks to periodic one. © 2015, Springer Science+Business Media Dordrecht.

Roy K.,Siksha Bhavana Visva Bharati | Saha T.,Siksha Bhavana Visva Bharati | Chatterjee P.,Siksha Bhavana Visva Bharati | Tribeche M.,University of Science and Technology Houari Boumediene
Physics of Plasmas | Year: 2012

Arbitrary amplitude dust-acoustic (DA) double-layers in a plasma with nonextensive electrons, two-temperature thermal ions, and warm drifting dust grains are addressed. It is shown that DA double-layer structures, the onset of which depends sensitively on the plasma parameters, can exist. In particular, it may be noted that the electron nonextensivity may affect drastically the existence of these localized structures. In view of recent observation, our results should assist in the interpretation of the nonlinear double-layers observed in the downward current region of the aurora. © 2012 American Institute of Physics.

Roy K.,Siksha Bhavana Visva Bharati | Saha T.,Siksha Bhavana Visva Bharati | Chatterjee P.,Siksha Bhavana Visva Bharati
Astrophysics and Space Science | Year: 2013

The problems of large amplitude double layers are discussed using Sagdeev's pseudo-potential technique for a dusty plasma comprising two temperature isothermal ions and nonextensive nonthermal velocity distributed electron. For different sets of plasma parameter values, the Sagdeev potential V(φ{symbol}) has been plotted. It is found that nonextensive q parameter plays a significant role in determining the shape and size of large amplitude double layers. Also, it is observed that the existence of large amplitude double layers depends on different plasma parameters. © 2013 Springer Science+Business Media Dordrecht.

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