A Korteweg–deVries equation with an additional term due to the density gradient is obtained using reductive perturbation technique in an unmagnetized plasma having a density gradient, finite temperature ions, and two-temperature nonisothermal (trapped) electrons. This equation is solved to get the solitary wave solution using sine-cosine method. The phase velocity, soliton amplitude, and width are examined under the effect of electron and ion temperatures and their concentrations. The effect of ion (electron) temperature is found to be more significant in the presence of larger (smaller) number of trapped electrons in the plasma.

No abstract

Soliton generation mechanism in a double-plasma device is explored by carrying out diagnostics measurements using a Langmuir probe and laser induced fluorescence. Soliton profiles are investigated for different amplitudes, durations and frequencies of the applied grid signal. Particle-in-cell simulations are also carried out in order to study in detail the evolution and propagation mechanism of solitons. For low temperature ions, the simulation results show similar features as observed in the experiment. However, the simulations with fast ions having larger velocities than the soliton show strong interaction of the fast ions with the soliton and ion burst, producing another soliton through the energy exchange mechanism.

This paper aims at studying the oblique reflection of solitons in an inhomogeneous plasma having finite-temperature ions and trapped electrons (two-temperature nonisothermal electrons). In order to study the soliton reflection, a coupled equation is derived based on modified Korteweg-deVries equations for the incident and reflected solitons, and then, it is solved along with the use of incident soliton solution. The expressions for the reflected soliton amplitude, width, and reflection coefficient are obtained and examined for different parameter regimes. The reflection coefficient, which is the ratio of reflected and incident soliton amplitudes, is found to be independent of the ion and electron temperatures. It infers that both the amplitudes change in the same proportion with the ion and electron temperatures. It is observed that the soliton reflects with higher amplitude when the obliqueness is smaller. It is also seen that the reflected soliton undergoes a downshift in its original line of propagation. This downshift is further investigated in detail. The effect of the trapped electrons on the soliton reflection characteristics and on the downshift is also analyzed.