The Cairns-Tsallis model for ion acoustic cnoidal(periodic) waves

In this paper, considering the importance of ion acoustic waves in nonlinear phenomena of plasma, the combinedeffects of nonextensivity and nonthermality parameters on the ion acoustic cnoidal nonlinear waves studied. inthis regard, the hybrid cairns-tsallis distribution function used to describe the electrons and positrons. conditionsof formation of nonlinear ion acoustic waves and permissible values of nonextensivity (q) and nonthermality(α) parameters were determined and the behavior of these waves with changes in these parameters in thistype of plasma have been studied. for this purpose, we have used the reductive perturbation method (rpm)to derive the corresponding kdv equation for the ion acoustic wave, then considering the sagdeev potential,the conditions for the generation of ion acoustic waves in the cnoidal and soliton form discussed. the effect ofnonextensivity (q) and nonthermality (α) parameters on the sagdeev potential (potential well width and depth),wave amplitude and frequency investigated. the results show that for all of the acceptable values of q and α thecnoidal ion acoustic wave is compressive.