Dust-acoustic solitary modes in plasmas with isothermal and nonthermal ions: Polarity switches and coexistence domains

Journal Article · Mon Aug 15 04:00:00 EDT 2011 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3610560· OSTI ID:22043443

Verheest, Frank ^[1]

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1. Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281, B-9000 Gent, Belgium and School of Physics, University of KwaZulu-Natal, Private Bag X54001, Durban 4000 (South Africa)

Large dust-acoustic waves are investigated in a multispecies plasma model consisting of cold negative dust in the presence of cooler Boltzmann and hotter nonthermal Cairns positive ions, in a Sagdeev pseudopotential formalism. Use of the pseudopotential at the acoustic speed itself yields in a systematic way compositional parameter values where negative/positive solitons interchange polarities and also where both polarities coexist. The latter requires that solitons at the acoustic speed exist, with finite amplitudes, compared to superacoustic solitons of the opposite polarity. The coexistence region starts when the pseudopotential at the acoustic speed has a negative root at the limit of infinite dust compression and ends when a positive double root is encountered. Outside the coexistence domain, only negative or positive superacoustic solitons can exist. Thus, the discussion and numerical evaluations are guided by precise physical and analytic arguments rather than mere numerical experimentation. Graphs of relevant Sagdeev pseudopotentials illustrate the link with the analytical constraints.

• OSTI ID: 22043443
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 8 Vol. 18; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
AMPLITUDES
CATIONS
COMPRESSION
HEAT EXCHANGERS
ION ACOUSTIC WAVES
PLASMA
PLASMA SIMULATION
SOLITONS
SOUND WAVES