7 Asia-Pacific Conference on Plasma Physics, 12-17 Nov, 2023 at Port Messe Nagoya
thZonal flow generation by small-scale drift-ion-acoustic waves in electron–positron–ion plasmas

L.Z. Kahlon1, I. Javaid1, T.D. Kaladze2, H. A. Shah11Physics Department, Forman Christian College (A Chartered University), Ferozpur Road, 54600
Lahore, Pakistan; lailakahlon@fccollege.edu.pk ; lailakahlon192@gmai.com
2
I. Vekua Institute of Applied Mathematics of Tbilisi State University, Tbilisi, Georgia
3
E. Andronikashvili Institute of Physics, I. Javakhishvili Tbilisi State University, 0128 Tbilisi,
Georgia
Many laboratory and astrophysical medium
frequently form the three-component plasma containing
electrons, positrons, and ions (EPI plasma). The study of
low-frequency long wavelength drift and ion-acoustic
waves (DIAWs) has great attention due to its
applications to many laboratory, space, and astrophysicalsystems. This problem received much attention due tothe possibility of the formation of spatiallythree-dimensional different nonlinear solitary structures(vortices and zonal flows) in multicomponent plasmas.
Such interest of DIAWs is connected with the generationof sheared zonal flow spontaneously arising in laboratory
plasmas as a consequence of the secondary instability ofplasma due to the nonlinear interaction between theprimary oscillations. Note that the existence of spatially
isolated sheared zonal flows is an integral property ofmany planetary atmospheres and laboratory plasmas
controlling anomalous transport of heat and particles
across the magnetic surfaces of plasma confinement
systems due to the energy transport toward large-scale
structures as a result of inverse energy cascade [1, 2, 3].
In the present work, we investigate the possibilityof generation of the zonal flow for low-frequency
coupled electrostatic DIAWs in an electron–positron–ion
plasma and its corresponding growth rate is analyzed
both analytically and numerically. We will draw ourattention to the small-scale (!" # ≥ 1, where # is theion Larmor radius defined at the electron temperature)solitary structures. The parametric interaction
formulation is used to investigate the instabilities ofzonal flows driven by a monochromatic wave packet ofprimary modes.
To describe the nonlinear propagation of electrostatic
drift and ion-acoustic waves (DIAWs), the generalized
Hasegawa-Mima equation containing both vector(Jacobian) and scalar (Korteweg-de Vries type)nonlinearities is obtained for electron-positron-ion (EPI)
plasmas [3]. In addition, density and temperature
non-homogeneities of electrons and positrons are taken
into account. Appropriate set of 3D equations consistingof generalized Hasegawa-Mima equation for theelectrostatic potential and equation of parallel tomagnetic field motion of ions where vector nonlinearity
is taken into account for short-scale DIAWs [4].
We have shown that the dynamics oflow-frequency waves studied in usual EI plasmas [5] isgenerally modified in EPI plasmas [3, 6]. Density andtemperature inhomogeneity of electrons and positrons istaken into account. The generalized HM equation
containing both vector and scalar nonlinearities valid forarbitrary sizes of structures is obtained. We have shownthat due to the existence of positrons in the plasma the** (,)*
sign of the derivative &'()(,)= '.)− '0)(,) maychange, which in turn enriches the class of solutions of
the generalized HM equation. The appropriate dispersion
equation and propagation frequency of drift andion-acoustic waves (DIAWs) are obtained.
The modified parametric approach is developed
for the monochromatic primary modes. Accordingly, theinteraction of a pump drift-ion-acoustic waves, twosatellites of the pump waves (sideband waves), and asheared zonal flow is studied. The driving mechanism of
this instability is the Reynold stress and the meanelectromotive force. The obtained results are applied tolaboratory plasma experiments, that were considered forthe case when !" # ≥ 1. The corresponding expressions
for the growth rate are found.
This study shows that the parametric instability
presented here is a sufficient nonlinear mechanism todrive large-scale zonal flows in EPI laboratory plasmas.
The results obtained in the present study may be applied
to the large-scale inhomogeneities in density of theuniverse and also to the astrophysical EPI jets where ionsconcentrations are taken as small fractions of theelectron–positron plasma number densities.
Finally, the mathematical results and graphicalanalysis in this paper highlight the importance of effects
that have not been taken into account in earlier works. In
the numerical work, we analyze the dependence ofgrowth rate on different parameters zonal wave vector,
presence of positron and scale length. It is shown that
how the presence of positron enhances the growthrate.[7]References:[1] M.J. Rees, in The Very Early Universe, ed. by G. M.
Gibbons, S. W. Hawking, S. Siklas. (Cambridge
University Press, Cambridge, 1983)[2] A. Mushtaq, H.A. Shah, Phys. Plasmas 12, 072306(2005)[3] L.Z. Kahlon, I. Javaid, Chin. Phys. Lett. 34(12),123201 (2017)[4] T.D. Kaladze, L.V. Tsamalashvili, L.Z. Kahlon, J.
Plasma Phys. 77, 813 (2011)[5] T.D. Kaladze, M. Shad, H.A. Shah, Phys. Plasmas 16,024502 (2009)[6] I. Javaid, L.Z. Kahlon, H. A. Shah, T.D . Kaladze,
Phys. Plasmas, 29, 112109 (2022)