9 research outputs found
New Longitudinal Waves in Electron-Positron-Ion Quantum Plasmas
A general quantum dispersion equation for electron-positron(hole)-ion quantum
plasmas is derived and studied for some interesting cases. In an
electron-positron degenerate Fermi gas, with or without the Madelung term, a
new type of zero sound waves are found. Whereas in an electron-hole plasmas a
new longitudinal quantum waves are revealed, which have no analogies in quantum
electron-ion plasmas. The excitation of these quantum waves by a low-density
monoenergetic straight electron beam is examined. Furthermore, the KdV equation
for novel quantum waves is derived and the contribution of the Madelung term in
the formation of the KdV solitons is discussed
Head-on collision of ion thermal solitary waves in pair-ion plasmas containing charged dust impurities
In the present research paper, the study of the head-on collision between two ion thermal solitary waves is investigated in a two-fluid (i.e., a pair-ion) plasma consisting of positive and negative ions as well as a fraction of stationary (positively/negatively) charged dust impurities, using the extended Poincaré-Lighthill-Kuo method. The effects of the concentration of charged dust impurities and the positive-to-negative ion temperature ratio on the solitary waves collisions are investigated. It is found that the phase shift is significantly affected by the presence of the positive-to-negative ion temperature ratio and positively/negatively charged dust grains