Dust Ion Acoustic Solitary Structures at the Acoustic Speed in the Presence of Nonthermal Electrons and Isothermal Positrons
- 17 Downloads
The Sagdeev pseudo-potential technique and the analytic theory developed by Das et al. [J. Plasma Phys.78, 565 (2012)] have been used to investigate the dust ion acoustic solitary structures at the acoustic speed in a collisionless unmagnetized dusty plasma consisting of negatively charged static dust grains, adiabatic warm ions, nonthermal electrons, and isothermal positrons. The present system supports both positive and negative potential solitary waves at the acoustic speed, but the system does not support the coexistence of solitary structures of opposite polarity at the acoustic speed. The system also supports negative potential double layer at the acoustic speed, but does not support positive potential double layer. Although the system supports positive potential supersoliton at the supersonic speed, but there does not exist supersoliton of any polarity at the acoustic speed. Solitary structures have been investigated with the help of compositional parameter spaces and the phase portraits of the dynamical system describing the nonlinear behavior of the dust ion acoustic waves at the acoustic speed. For the case, when there is no positron in the system, there exist negative potential double layer and negative potential supersoliton at the acoustic speed, and, for such case, the mechanism of transition of supersoliton to soliton after the formation of double layer at the acoustic speed has been discussed with the help of phase portraits. The differences between the solitary structures at the acoustic speed and the solitary structures at the supersonic speed have been analyzed with the help of phase portraits.
The authors are grateful to the reviewer for his constructive comments for the improvement of this paper.
One of the authors (Ashesh Paul) is thankful to the Department of Science and Technology, Govt. of India, INSPIRE Fellowship Scheme, for financial support.
- 1.P. K. Shukla and M. Marklund, Phys. Scr. T113, 36 (2004).Google Scholar
- 2.I. B. Zel’dovich and I. D. Novikov, Relativistic Astrophysics, Vol. 2: The Structure and Evolution of the Universe (University of Chicago Press, Chicago, 1971).Google Scholar
- 10.R. L. Merlino, Plasma Phys. Appl. 81, 73 (2006).Google Scholar
- 25.A. Das, A. Bandyopadhyay, and K. P. Das, arXiv Preprint No. 1110.5307 (2011). https://arxiv.org/pdf/1110.5307v2.pdf.Google Scholar
- 29.R. Z. Sagdeev, Reviews of Plasma Physics, Ed. by M. A. Leontovich (Consultants Bureau, New York, 1968), Vol. 4, p. 23.Google Scholar