Large amplitude dust-acoustic solitary waves and double layers in nonthermal plasmas

A systematic investigation has been made of large amplitude dust-acoustic solitary waves in plasmas consisting of negatively charged cold dust in the presence of either nonthermally distributed ions or electrons, with a particular emphasis on the delimitation of the compositional parameter space where such structures can be generated. The occurrence of negative electrostatic potential solitary waves is for higher Mach numbers limited by infinite dust compression. On the positive potential side solitary waves are possible until double layers are encountered, provided two distinct aspects of the dusty plasma compositions are fulfilled: Sufficient nonthermality in the ions and sufficient negative charge on the dust, the electron presence not really being required. There is then a region in parameter space where both negative and positive solitary structures can coexist. When electrons are the nonthermal plasma constituent, only negative potential waves are possible.