Linear and nonlinear analysis of Ion-Temperature-Gradient (ITG) driven mode in the asymmetric pair-ion magnetoplasma

Abstract

We have investigated linear and nonlinear dynamics of ion-temperature-gradient (ITG) driven drift mode for Maxwellian and non Maxwellian pair-ion plasma embedded in an inhomogeneous magnetic field having gradients in the temperature and number density of ions. Linear dispersion relations are derived and analyzed analytically as well as numerically for different cases. It has been found that growth rate of instability increases with increasing η. By using the transport equations of Braginskii, model, a set of nonlinear equations are derived. In the nonlinear regime, soliton structures are found to exist. Our numerical analysis shows that amplitude of solitary waves increases by increasing ion to electron number density ratio. These solitary structures are also found to be sensitive to asymmetries in pair plasma and non thermal kappa and Cairns distributed electrons. Our present work may contribute a good illustration of the observation of nonlinear solitary waves driven by the ITG mode in magnetically confined pair-ion plasmas and space pair-ion plasmas as the formation of localized structures along drift modes is one of the striking reasons for L-H transition in the region of improved confinements in magnetically confined devices like tokamaks.