Propagation and head-on collisions of ion-acoustic solitons in a Thomas-Fermi magnetoplasma: Relativistic degeneracy effects

Small amplitude propagation and quasielastic head-on collision of ion-acoustic solitary waves (IASWs) are investigated in a degenerate Thomas Fermi electron-positron-ion magnetized plasma using extended Poincare-Lighthill-Kuo reductive perturbation method for both ultrarelativistic and nonrelativistic electron/positron degeneracy cases. It is observed that both bright- and dark-type solitary shapes can exist in such plasma, depending on two critical values. The shape of ion-acoustic solitary structures as well as sign of their collision phase shifts are both determined by the same critical values. It is further revealed that relativistic degeneracy of electrons/positrons has significant effect on the propagation as well as interaction of IASWs. (C) 2010 American Institute of Physics. [doi:10.1063/1.3449590]