Neutral Dynamics and High Frequency Electromagnetic Mode in Partially Ionised Plasma

Abstract

A general dispersion relation for the high frequency domain in a (u ? X i ) partially, ionized, inhomogeneous and magnetised plasma is derived by incorporating neutral dynamics. Plasma and neutral Ñuids are described by basic two Ñuids and MaxwellÏs equation [Alfve n, H. and Falthammar, C. G., ""Cosmical ElectrodynamicsÏÏ (Oxford 1963)]. It is emphasized that the introduction of neutral dynamics not only generates neo-modes or neoclasses of instabilities but also modiÐes earlier results [Huba, J. D., Phys. Fluids B3, 3217 (1991) and Phys. Plasma 2, 2504.]. The importance of a magnetic Ðeld gradient with neutral density gradient in generating these modes has also been demonstrated. The probable candidacy of the Ðndings is discussed.

New low-frequency electromagnetic modes associated with neutral dynamics in partially ionised plasma

“…Hence there is a natural motivation to look for the EM (electromagnetic) part of the problem with a broader aspect in PIP. We would like to mention from the outset that there exists some work pertaining to the role of neutral species (Huba, 1990;Shaikh et al, 1999;Christopher and Jeremy, 2004;Song and Vasyliunas, 2005), to the best of our awareness, in the investigation of EM mode in PIP. Huba (1990) has presented a two-fluids model for PIP which was restricted to the analysis of the Rayleigh-Taylor type mode with the exclusion of neutral compressibility.…”

“…Huba (1990) has presented a two-fluids model for PIP which was restricted to the analysis of the Rayleigh-Taylor type mode with the exclusion of neutral compressibility. Shaikh et al (1999) have analysed high-frequency EM modes, with the same model, to study the effect of neutral dynamics in PIP. The work of Christopher and Jeremy (2004) was an experimental study on the Alfvén wave based on the simple theoretical model without ∇ × B effect in the neutral momentum equation and hence the subsequent effect of this term does not appear in their results.…”

Energy Loss of a Test Charge in Collisional Dusty Plasmas

“…Recently, attempts have been made to investigate the e¡ect of dust-neutral collisions on the dust-acoustic (DA) waves in partially ionized dusty plasma [9] and in strongly coupled dusty plasmas [10]. Their e¡ects on the damping of surface waves [11] and on the dynamics of neutrals in both low and high-frequency electromagnetic modes [12] were also investigated. A wide variety of acoustic modes [13] and boundary e¡ects [14] thereon were also studied in collisional dusty plasma.…”