Suprathermality Effects on Propagation Properties of Ion Acoustic Waves

A theoretical investigation is carried out to understand the basic features of ion-acoustic (IA) waves in an unmagnetised plasmas including cool ions, hot ions having a kappa distribution and kappa-distributed electrons, using small amplitude techniques. The effects of excess suprathermal ions, the ion temperature T_i and electron temperature T_e as well as the density ratio on the IA waves are studied. It is found that the suprathermality effects play an important role in the system, as the geometric characteristics of the IA solitons are found to be significantly affected through the ion and electron suprathermal index. In the presence of suprathermality effects, either polarity is in principle supported by this plasma model.