Effect of entropy on soliton profile in ITG driven magneto-plasma

Abstract

Interconnection of entropy with the density and temperature of plasmas leads us to investigate the effect of entropy on different plasma related phenomena. By using Braginskii's transport equations and a transformation, the linear dispersion relation and the KdV equation for the ion temperature gradient (ITG) mode having entropy drift are derived. It is found that this mode supports only compressive solitons. Due to entropy drift, a parameter ηi=Ln/LT is observed in the KdV equation. We found that the soliton profile is sensitive to entropy, i.e., due to the changes in the entropy amplitude and the width of solitons. It is also observed that the increasing ion temperature and increasing magnetic field affect the shape of the soliton. The results are briefly compared with the well-known results of the soliton profile, and a change in the structure of the soliton profile is found by introducing entropy in the ITG mode. This work may be helpful in the study of entropy based models and in understanding the formation of nonlinear solitary waves driven by the ITG mode in magnetically confined plasmas in the presence of entropy. For illustration, the model has been applied to tokamak plasmas.