ION-ACOUSTIC SOLITONS IN A PLASMA WITH FINITE-TEMPERATURE DRIFTING IONS - LIMIT ON ION DRIFT VELOCITY

Propagation of ion acoustic solitons in a plasma consisting of finite temperature drifting ions and nondrifting electrons has been studied. It is shown that in addition to the electron inertia and weak relativistic effects, the ion temperature also modifies the soliton behavior. By including the finite ion temperature, limit for the ion drift velocity u0 for which the ion acoustic solitons are possible, is obtained. The solitons can exist for v(Te) less-than-or-equal-to u0 less-than-or-equal-to \u0max\, where v(Te) is the electron thermal velocity and u0max is the maximum value of the ion drift velocity. The maximum value of this velocity is decided by the ion temperature. Under the limiting conditions, the Korteweg-de Vries (KdV) equation is derived for one-dimensional ion acoustic soliton. Expressions are obtained for the soliton phase velocity, peak soliton amplitude, soliton width, and the soliton energy. The present results correspond to those of the previous investigations under appropriate plasma conditions.