Reflection of modified Korteweg–de Vries solitons in a negative ion plasma

Abstract

Reflection of modified Korteweg–de Vries solitons from the sheath in front of a negatively biased metal disk is experimentally investigated in a negative ion plasma. Both rarefactive and compressive solitons are reflected and the polarity of the reflected solitons is the same as that of the incident solitons. The points of reflection for the rarefactive and compressive solitons are at different locations. As the magnitude of the negative bias potential that is applied to the reflector is increased, the two reflection points move away from the reflector. An interpretation in terms of the sheath characteristics is presented.

Soliton propagation in an inhomogeneous plasma at critical density of negative ions: Effects of gyratory and thermal motions of ions

“…Moreover, when we calculate the critical negative ion density ratio r 0 from Eq. ͑1͒ for = 0, it is obtained as 0.268, which is exactly the same as obtained by Yi et al 32 for m p / m n = 1. Therefore, these comparisons and the limiting cases substantiate the generality of our calculations.…”

Reflection of Solitons at Critical Density of Negative Ions: Contribution of Thermal and Gyratory Motions of Ions

“…Interestingly, the first term in the right hand side of (19) causes the base of the reflected soliton to shift either upward or downward, the magnitude of which depends upon the peak amplitude of the incident soliton as well as on the other parameters in the plasma. Here, it is worth mentioning the observation of Yi et al [22] in an unmagnetized plasma that both the compressive and rarefactive solitons are reflected without shift and the polarity also remains the same after their reflection. Therefore, the two observations emphasize the difference made by the thermal motions of the ions and the magnetic field in the plasma.…”

“…The interesting property of the solitons is that they get reflected from the density gradient present in the inhomogeneous plasmas [16]- [21]. Their reflection has been investigated experimentally in negative-ion-containing plasmas [4], [22], [23] and in nonnegative ion plasmas [16]- [19], [24]. Also, a large number of studies have been carried out by theoretical researchers in this direction [9], [10], [20], [21], [25], [26].…”

Soliton reflection in a negative ion containing plasma: Effect of magnetic field and ion temperature

“…In addition to the soliton reflection in ordinary plasmas, the propagation of ion acoustic solitons [16][17][18][19] and their reflection [20][21][22][23] in an unmagnetized inhomogeneous plasma having both the positive and negative ions has been reported. For studying the soliton reflection problem theoretically, modified KdV equations for incident and reflected solitons were derived using the reductive perturbation analysis and then solved after their coupling.…”