Abstract
Electrostatic solitons formation parallel to the magnetic field in pair-ion plasmas are studied for spherical and cylindrical geometries. A modified Korteweg-de Vries equation is obtained using the reductive perturbation technique. It is found that both electrostatic hump and dip type structures are formed in nonplanar geometries depending on the temperature difference between positively and negatively charged ions. The numerical solution shows that amplitude of the soliton is large in pherical geometry in comparison with cylindrical geometry The soliton solutions are also presented by choosing different ion temperature ratios of the positive and negative ions to understand some aspects of laboratory produced fullerene plasmas. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3356057]