Exact numerical analysis of EMEC mode instability in more realistic Cairns distributed non-thermal plasmas.

Non-thermal plasma systems beyond the state of thermal equilibrium must have non-thermality dependent effective temperatures. These particle populations cannot have Maxwellian temperatures T ∥ , ⊥ e (M) which are typically considered at thermal equilibrium in the context of Maxwellian plasmas. Previously, in such dilute environments, numerous non-thermal distributions incorporating the concept of Maxwellian temperature T ∥ , ⊥ e (M) have been utilized, one of them is Cairns distribution (here termed as type-A). To ameliorate this inconsistency, we propose a more realistic form of Cairns distribution (type-B) with the vigorous definition of effective temperature and effective thermal velocity. Both Cairns distributions (A and B) are utilized to calculate the transverse dielectric response function (TDERF) of electromagnetic electron cyclotron (EMEC) mode. The exact numerical solution of TDERFs of EMEC instability reveals interesting and more promising repercussions in the case of Cairns-B i.e. an augmentation in the behavior of oscillatory and imaginary frequencies of the instability. • Nonthermal populations beyond thermal equilibrium have effective temperatures. • Effective temperatures update plasma betas because of nonthermality dependence. • Cairns distribution shows an appreciable agreement with the observed distribution in solar wind. • Model-B style distributions better explain plasma dynamics, waves and instabilities. • Model-B explains natural rise in temperature due to increase in nonthermality in system. [ABSTRACT FROM AUTHOR]