Modified Korteweg de Vries (MKdV) and Korteweg de Vries (KdV) Solitons in a Warm Plasma with Negative Ions and Electrons' Drift Motion

Abstract

In this investigation, both compressive and rarefactive Korteweg de Vries (KdV) solitons of high amplitude are shown to exist in a warm plasma under the influence of electrons' drift motion for different values of Q^′ (=m_j/m_i, negative to positive ion mass ratio) greater or less than one. But these KdV solitons of high amplitude are noticed in the plasma for negligible temperature α (=T_i/T_e, ion to electron temperature ratio → 0) for Q^′<1 subject to the electrons' drift motion. Interestingly, the formation of higher amplitude (<1) MKdV solitons in the entire range of drift velocity (v_e^′) for Q^′<1 is found as more favourable than those for Q^′>1 in an upper range of v_e^′≥ 45 when temperature is small. On the other hand, for concentration of heavier population of negative ions (Q^′>1) in the warm plasma, MKdV solitons of small but significant amplitude are established to exist even in a new range (45≤ v_e^′≤ 60).