Nonlinear low-frequency structures in an electron–positron–ion plasma

Abstract

Nonlinear ion cyclotron and ion-acoustic waves have been studied in an electron–positron–ion plasma. Using Boltzmann distributions for the electrons and positrons and fluid equations for the ions, a set of nonlinear equations in the rest frame of the propagating wave is derived and numerically solved for the electric field. A scan of parameter space reveals a range of solutions for the parallel electric field, from sinusoidal to sawtooth to highly spiky waveforms. The results are compared with satellite observations.

Periodic low-frequency electric field structures in a magnetized non-thermal auroral plasma

“…For the present model, the unnormalized electric field is given as [14], [17], [18]EUNbadbreakafter=EMTeeρi. Note that the ratio of the Mach numbers, M2M1 is equal to the amplitudes of the electric field E1E2, i.e., E1false(E2false) is the electric field corresponding to the Mach number M1false(M2false). In this paper, the electric field structures obtained are for electron temperature Tegoodbreakafter=1goodbreakafter−10 eV [9] and the ion-cyclotron frequency of about normalΩi≈1000 rad/sec.…”

“…Further investigations revealed that BENs consist of non-linear, quasi-static, time-domain parallel or/and perpendicular electric field structures, such as spiky, sawtooth and sinusoidal structures in an electrostatic ion cyclotron (EIC) wave reported by S3-3 [8], Viking [9], FREJA [10], POLAR [11], [12] and FAST [13] satellites. Various theoretical investigations of such electric field structures parallel and perpendicular to the geomagnetic field line have been done by several authors [14], [15], [16], [17], [18] using the fluid theory technique. In order to explain the generating mechanism of the parallel electric field fluctuations which exhibit sawtooth or spiky wave structures observed by FAST satellite mission, Reddy et al [14] presented a magnetized two-component auroral plasma model consisting of a cold ion and Boltzmann electron distribution, which is responsible for the field-aligned current.…”

Head-on Collision of Ion-acoustic Multi-Solitons in e-p-i Plasma

“…A lot of research has been carried out to study the e-p and e-p-i plasmas in the past few years. [14−18] For instance, Moolla et al [19] investigated nonlinear low frequency structures in e-p-i plasma. Baluku and Hellberg [20] investigated the effect of nonthermal electrons on IASWs in an e-p-i plasma.…”