مشخصات پژوهش

Using the generalized hydrodynamic model, the possibility of var iety of large amplitude nonlinear excitations is examin ed in electron-i on plasma wit h arb itrary electron degeneracy considering also the ion temperature effect. A new energy-density relation is proposed for plasmas with arbitrary electron degeneracy which reduces to the classical Boltzmann and quantum Thomas-F ermi counterparts in the extreme limits. The pseudopotential metho d is employed to find the criteria for existence of nonlin ear structures such as solitons, per iodic nonlinear structures, and double-layers for different cases of adiabatic and isothermal ion fluids for a whole range of norm alized electron chemical potential, g0, ranging from dilute classical to completely degenerate electron fluids. It is observed that there is a Mach-speed gap in which no large amplitude localized or periodic nonlinear excitations can propagate in the plasma under consideration. It is further revealed that the plasma under investigation supports propagation of double-wells and double-layers the chemical potential and Mach number ranges of which are studied in terms of other plasma parameters. The Mach number criteria for nonlinear waves are shown to significantly differ for cases of classical with g0 < 0 and quantum with g0 > 0 regimes. It is also shown that the localized structure propagation criteria possess significant dissimilarities for plasmas with adiabatic and isothermal ions. Current research may be generalized to study the nonlinear structures in plasma containing positrons, multiple ions with different charge states, and charged dust grains.