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Formation of Large Amplitude Solitons and Small Amplitude Double Layers in Two-temperature Non-isothermal Electron Plasma

Received: 23 October 2024     Accepted: 15 November 2024     Published: 30 December 2024
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Abstract

Propagation of large amplitude ion-acoustic solitary waves and small amplitude double layers have been investigated in a two-temperature non-isothermal electron plasma consisting of warm positive ions, warm negative ions and warm positrons by Sagdeev pseudopotential method (SPM). Small amplitude double layer solution (ϕDL) is also discussed theoretically in this paper for further investigation. Fully non-linear large amplitude compressive solitary waves and small amplitude compressive double layers are presented graphically by the corresponding figurs 1 – 14 under the variation of different values of the mass ratios (Q) of negative to positive ions, phase velocities (V) of solitary waves, negative ion concentrations (njo), positron densities (χ) and temperature ratios (σp) of electrons (Te) and positrons (Tp). Consequently this large amplitude electrostatic solitary waves and small amplitude electrostatic double layers in complex plasmas have broad applications in space plasma Physics, Astrophysics, Fusion technology, Plasma – based devices and Fundamental wave research, offering tools for exploring wave-particle interactions, stability and energy transfer in multi-species plasmas.

Published in American Journal of Physics and Applications (Volume 12, Issue 6)
DOI 10.11648/j.ajpa.20241206.11
Page(s) 112-122
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This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited.

Copyright

Copyright © The Author(s), 2024. Published by Science Publishing Group

Keywords

Solitary Waves, Two-Temperature Non-Isothermal Electron Plasma, Double Layers, Double Layer Width and Amplitude, Double Layer Velocity

1. Introduction
Propagation of large amplitude ion-acoustic solitary waves and small amplitude ion-acoustic double layers have been investigated theoretically in a plasma consisting of warm positive ions, warm negative ions and warm positrons along withisothermal,non-isothermal and non-thermal electronsby many authors . A large number of physicists investigated various types of solitary waves for warm or cold ions with magnetized or unmagnetized plasmas in presence of two-temperature or single-temperature non-isothermal electrons. Solitary waves became more interesting when negative ions are found in space plasmas. This negative ions are observed in D and F regions of the earth’s ionosphere, in Saturn’s moons and in Halley’s cometarycomae. Wong, Mamas and Arnush discussed a method for producing plasmas with total replacement of electrons by negative ions. On the other hand, non-isothermal electrons give rise many interesting results in the propagation of waves. It is also found that two-temperature Maxwellian distribution of electrons presents a better result nearer to the experimental datafor the formation of solitons and double layers. Ion-acoustic double layershave been extensively studied theoretically as well as experimentally by many plasma physicists. Das et al, Watanabe and Tagare investigated theoretically and Cooney et alinvestigated experimentally the ion-acoustic solitary waves in a multispecies plasma. Mishra et alstudied the ion-acoustic compressive and rarefactive double layers in a warm plasma by reductive perturbation method. Consequently Merlino and Loomisdiscussed strong double layers experimentally for (Ar+, SF6-) plasma.Chattopadhyay et al also studied the effect of negative ions on the formation of ion-acoustic solitons for cold and warm ions in relativistic and in non-relativistic plasmas by Sagdeevpseudopotential method.In magnetized plasma with or without negativeions, Ghosh et al and Das et al studied the ion-acoustic solitary waves by a new analytical method and reductive perturbation method. In the auroral and magnetospheric plasmas, ion-acoustic double layers have been observed for two-electron species . It is therefore interesting to investigate the ion-acoustic double layers in aplasmawhere negative ions and two-temperature electron distributions present simultaneously. Again, the electrostatic waves show a significant change and behave differently when positrons are introduced in addition to three component plasmas. Popel et al found that the amplitude of ion-acoustic solitary waves could be considerably reduced when hot positrons were present. We are now wishing to study the ion-acoustic solitary waves and double layers when positrons are included in our system for two-temperature non-isothermal electron plasmas. In presence of warm negative ions, warm positive ions and warm positrons, the present author in recent year discussed critically the solitary waves and small amplitude double layers under the variation of different plasma parameters for two-temperature non-isothermal electron plasmas by SPM.
The aim of this paper is to discuss the large amplitude ion-acoustic compressive solitary wavesand small amplitude ion-acoustic compressive double layers in a multicomponent plasma consisting of warm positive ions, warm negative ions, warm positrons and two-temperature non-isothermal electrons by SPM. By taking some plasmas containing ion species (Ar+, SF6-), (H+,O2-)and (He+,O-), the profiles of Sagdeev potential function ψ(φ) for large amplitude ion-acoustic compressive solitons and small amplitude compressive double layers are drawn under the variation of negative to positive ion mass ratios (Q),phase velocities (V) of solitary waves, negative ion concentrationsnjo, positron density (χ) and temperature ratios (σp) of electronsTe andpositrons Tp.
The plan of this paper is arranged in the following ways:
The basic set of normalized fluid equations for positive ions, negative ions along with Poisson’s equations, concentrations of two-temperature non-isothermal electrons and warm isothermal positrons are given in Sec.2. The Sagdeev potential function ψ(φ) for soliton is given in this section. By using the double layer conditions, the profiles of Sagdeev potential function ψ(φ) for small amplitude compressive double layers and double layer solutionsϕDL are stated clearly in this part. In sec.3,the entire problem is discussed critically under the variation of different plasma parameters. Concluding remarks are given in sec.4.
2. Formulations
In presence of warm positrons, the set of normalized fluid equations for a collisionless, unmagnetized, non-relativistic plasma containing warm positive ions, warm negative ions and two-temperature non-isothermal electrons along with charge neutrality condition are given in the following ways:
nit+x (niui)= 0 (1)
uit+uiuix+σinipix -=фx(2)
pit+uipix+ 3piuix= 0(3)
njt+x (njuj)= 0(4)
ujt+ujujx+σjQnjpjx=ZQфx (5)
pjt+ujpjx+ 3pjujx= 0(6)
2фx2=ne-ni+ Znj-np(7)
Charge neutrality condition is
1 + Znjo=nio+ χ(8)
where
ne=
ne= (9)
np= χe-σpϕ(10)
bl=1-βlπ,bh=1-βhπ,bl1=1-βl2π,bh1=1-βh2π,β1=Tel,fTeh,f,
βl=Tel,fTel,t,βh=Teh,fTeh,t, µ+ν = 1
σp = TeffTp,σi = TiTeff,σj = TjTeff,Teff = TelTehμ Teh+ ν Tel;
For non-isothermal plasma 0 <bl or bh<1π and 0 <bl1 or bh1<1π
In this case, Tel,f = temperature of free electrons in low temperature,Teh,f = temperature of free electrons in high temperature, Tel,t = temperature of trapped electrons in low temperature, Teh,t = temperature of trapped electrons in high temperature,Teff = effective temperature of electrons, Tp = temperature of positrons, Ti = temperature of positive ions, Tj = temperature of negative ions.
The concerned plasma parametersni,nj,ne, np, ui,uj, pi ,pj, σi,σj, ϕ, Z,Q, χ,σp,x, t, µ, ν,β1,βl,βh,bl,bh,bl1and bh1 in equations (1) to (10)are respectively the density of positive ions, negative ions, electrons and positrons, the velocity of positive ion and negative ions, the pressure of positive ions and negative ions, the temperature of positive ions and negative ions, the electrostatic potential, charge of ions, mass ratio of negative to positive ions, density of positron at ϕ = 0, temperature ratio of electrons and positrons, distance, time, the unperturbed number density of low temperature and high temperature electrons, the temperature ratio of free electrons in low and high temperatures, the temperature ratio of free and trapped electrons in low temperature, the temperature ratio of free and trapped electrons in high temperatureand the normally used conventional non-isothermal parameters related with βl and βh.
In this paper the boundary conditions for our systems are
ninio,njnjo,uiuio,ujujo,pi1,pj1,ne1,npχand ф0atx
In equations (1) to (7), the Galelian transformation η = x – V tis used where V is the velocity of the solitary waves.
Following Chattopadhyay , the expression for Sagdeev pseudopotential function ψ(ϕ) for two-temperature non-isothermal electron plasmas with warm positive ions, warm negative ions and warm positrons, is obtained as
ψ(ϕ) = [-ϕ-12ϕ2+815µbl+ νbhβ132(µ+ νβ1)32ϕ52-16µ+ νβ12(µ+ νβ1)2ϕ3+16105µbl1+νbh1β152(µ+ νβ1)52ϕ72-124µ+ νβ13(µ+ νβ1)3ϕ4+......]
+16nio33σiV-uio-3σinio2-2ϕ32- V-uio+3σinio2-2ϕ32+V-uio+3σinio3- V-uio-3σinio3
+16Q3nio33σjV-ujo-3σjQnjo2+2Q32- V-ujo+3σjQnjo2+2Q32+V-ujo+3σjQnjo3- V-ujo-3σjQnjo3+χσp(1-e-σpϕ) (11)
Where
ni=12nio33σiV-uio+3σinio2-2ϕ – V-uio-3σinio2-2ϕ(12)
nj=12Qnjo33σjV-ujo+3σjQnjo2+2Q – V-ujo-3σjQnjo2+2Q(13)
The requirements to yield soliton solutions from Sagdeev potential function ψϕ are
(i) ψϕ = ψϕϕ= 0at φ = 0.
(ii) 2ψϕϕ20 at φ = 0.
(iii) ψϕ = 0 at φ = ϕm andψϕ< 0 for 0 < φ <ϕm.
(iv) 3ψϕϕ3> 0 at φ = 0 for positive (compressive) potential solitons.
(v) ψϕϕ> 0 at φ = ϕm for positive (compressive) potential solitons.
And the restriction on ϕ is
-Q2ZV-ujo-3σjQnjo2<ф<12V-uio-3σinio2(14)
Now by using the Galelian transformation and the necessary boundary conditions, it is found from equations (7), (9), (10), (11), (12) and (13) after expansion of ψ(ϕ) in power series
d2ϕ2=H1ϕ-H2ϕ32+H3ϕ2-H4ϕ52+H5ϕ3--.......=ѱϕ(15)
And
ψ(ϕ)= -12H1ϕ2+25H2ϕ52-13H3ϕ3+27H4ϕ72-14H5ϕ4(16)
Where
H1=1-ni0(V-ui0)2-3σini0-1-Z2nj0Q(V-uj0)2-3σjnj0-1+χσp
H2=43μbl+νbhβ132μ+νβ132
H3=12μ+νβ12μ+νβ12-ni03223σi(V-ui0-3σini0)-3-(V-ui0+3σini0)-3+Z3nj0322Q3Qσj(V-uj0-3σjQnj0)-3-(V-uj0+3σjQnj0)-3- χσp2
H4=815μbl1+νbh1β152μ+νβ152
H5=1213μ+νβ13μ+νβ13-ni03223σi(V-ui0-3σini0)-5-(V-ui0+3σini0)-5+Z4nj0322Q23σjQ(V-uj0+3σjQnj0)-5-(V-uj0-3σjQnj0)-5+χσp33(17)
In order to get the small amplitude double layer profiles from Sagdeev potential functionψ(ϕ) and small amplitude double layer solutionsϕDL, the Sagdeev potential ψ(ϕ)should satisfy the following conditions :
ψ(ϕ) = 0atϕ= 0 andϕ=ϕdl
ψϕ= 0atϕ= 0 andϕ=ϕdl
2ψϕ2< 0atϕ= 0 andϕ=ϕdl
ψϕ< 0 for 0 <ϕ<ϕdlandϕ>ϕdl(18)
where ϕdl( > 0) is some extreme value of the electrostatic potential ϕat which double layer isproduced.
Now taking terms uptoϕ2 in equation (15) and ϕ3 in equation (16), we get finally after using the above boundary conditions for double layers as
H1=23H3ϕdlandH2=53H3ϕdl12(19)
In terms of H3 we get finally from equations (15) and (16) after simplification as
ψϕ= -13H3ϕ2ϕ - ϕdl2(20)
ψϕϕ= -13H3ϕϕ - ϕdl 3 ϕ - 2 ϕdl(21)
ϕDL=14ϕdl1-tanhH3ϕdl24 . η2(22)
Where H3> 0 represents the stable structure of double layer. Equations (20) to (22) give us the first order double layer profile and first order double layer solution.
3. Results and Discussions
In this section, the profiles of Sagdeev potential function ψ(ϕ) against electrostatic potential ϕfor large amplitude solitons and small amplitude double layers are drawn under the variation of different plasma parameters.
In Figure 1, the profiles of Sagdeev potential function ψ(ϕ) against electrostatic potential ϕfor large amplitude solitary waves are drawn under the variation of the mass ratios (Q) of negativemj to positive miions in presence χ0of positrons.
Figure 1. Profiles of Sagdeev potential function ψ(ϕ) against ϕ for large amplitude solitary wavesin two temperature non-isothermal electron plasma under the variation of the mass ratios (Q) of negative mjand positive miions in presence of positronsfor V = 1.601, uio = 0.4, ujo = 0.2, σi = 120,σj = 125,njo = 0.0501, nio = 0.88, χ = 0.1701, σp = 0.4101, µ = 0.15, ν = 0.85, bl = 0.15, bh = 0.4, β1 = 0.25, bl1 = 0.24, bh1 = 0.51, Z = 1 whenQ = 1.912, 3.997, 31.746.
In presence of positronsχ=0.1701 the curves a2 for Q = 1.912, a3 for Q = 3.997 and a4 for Q = 31.746 are shown in Figure 1, represent the solitary waves. The maximum value of the electrostatic potential ϕmfor large amplitude solitonsis increasing for increasing values of the mass ratios Q. The Sagdeev potential profiles ψϕ against ϕ for well shaped solitary waves denoted by a2,a3 and a4 cut the ϕ axis at ϕm = 0.277666, 0.284871 & 0.287948 respectively in Figure 1.
Figures 2, 3, 4 and 5 show the profiles of Sagdeev potential function ψ(ϕ) against electrostatic potential ϕfor large amplitude solitary waves under the variation of the phase velocities (V) of solitary waves in presence χ0of positrons.
Figure 2. Profiles of Sagdeev potential function ψ(ϕ) against ϕ for large amplitude solitary wavesin two temperature non-isothermal electron plasma under the variation of phase velocity (V) in presence of positrons for uio = 0.4, ujo = 0.2, σi = 120, σj = 125 ,njo = 0.0501, nio = 0.88 , χ = 0.1701, σp = 0, 0.4101, µ = 0.15, ν = 0.85, bl = 0.15, bh = 0.4, β1 = 0.25, bl1 = 0.24, bh1 = 0.51, Z = 1, Q =3.997 when V = 1.601.
Figure 3. Profiles of Sagdeev potential function ψ(ϕ) against ϕ for large amplitude solitary waves in two temperature non-isothermal electron plasma under the variation of phase velocity (V) in presence of positrons for uio = 0.4, ujo = 0.2, σi = 120,σj = 125, njo = 0.0501, nio = 0.88,χ = 0.1701, σp = 0.4101, µ = 0.15, ν = 0.85, bl = 0.15, bh = 0.4, β1 = 0.25, bl1 = 0.24, bh1 = 0.51, Z = 1, Q =3.997 when V = 1.69445.
The Sagdeev potential function ψϕ against ϕ for large amplitude solitary waves denoted bya5 in presence of positronsχ=0.1701for V = 1.601 with σi = 120,σj = 125is shown in Figure 2 whereas the curve a6 in presence of positronsχ=0.1701 for V = 1.69445 with σi = 120,σj = 125isshown in Figure 3. It is seen from Figure 3 that the curve a6 does not show any actual well shaped solitary waves for V = 1.69445 whereas the curve a5in Figure 2 cuts the ϕ axisat ϕm = 0.284871showing the actual well shaped soliton nature.In Figure 3, the curve a6 does not cut the ϕ axis which shows no solitonic structure.Under this different values of V, Figures 2 and 3 present whether the well shaped nature of soliton will form or not.
Figure 4. Profiles of Sagdeev potential function ψ(ϕ) against ϕ for large amplitude solitons in two temperature non-isothermal electrons under the variation of phase velocity (V) in presence of positron for uio = 0.5, ujo = 0.3, σi = 130,σj = 125,njo = 0.0501, nio = 0.88,χ = 0.1701, σp = 0.4101, µ = 0.15, ν = 0.85, bl = 0.15, bh = 0.4, β1 = 0.25, bl1 = 0.24, bh1 = 0.51, Z = 1, Q =3.997 when V = 1.601.Profiles of Sagdeev potential function ψ(ϕ) against ϕ for large amplitude solitons in two temperature non-isothermal electrons under the variation of phase velocity (V) in presence of positron for uio = 0.5, ujo = 0.3, σi = 130,σj = 125,njo = 0.0501, nio = 0.88,χ = 0.1701, σp = 0.4101, µ = 0.15, ν = 0.85, bl = 0.15, bh = 0.4, β1 = 0.25, bl1 = 0.24, bh1 = 0.51, Z = 1, Q =3.997 when V = 1.601.
Figure 5. Profiles of Sagdeev potential function ψ(ϕ) against ϕ for large amplitude solitary waves in two temperature non-isothermal electron plasma under the variation of phase velocity (V) in presence of positrons for uio = 0.5, ujo = 0.3, σi = 130,σj = 125,njo = 0.0501, nio = 0.88,χ = 0.1701, σp = 0.4101, µ = 0.15, ν = 0.85, bl = 0.15, bh = 0.4, β1 = 0.25, bl1 = 0.24, bh1 = 0.51, Z = 1, Q =3.997 when V = 1.69445.Profiles of Sagdeev potential function ψ(ϕ) against ϕ for large amplitude solitary waves in two temperature non-isothermal electron plasma under the variation of phase velocity (V) in presence of positrons for uio = 0.5, ujo = 0.3, σi = 130,σj = 125,njo = 0.0501, nio = 0.88,χ = 0.1701, σp = 0.4101, µ = 0.15, ν = 0.85, bl = 0.15, bh = 0.4, β1 = 0.25, bl1 = 0.24, bh1 = 0.51, Z = 1, Q =3.997 when V = 1.69445.
In Figure 4, the sagdeev potential profile ψϕ against electrostatic potential ϕfor large amplitude solitary waves in presence of positronsχ=0.1701 is denoted by the curve a7 when the temperature of positive σiand negativeσj ions are σi = 130 and σj = 125 with V = 1.601, uio = 0.5, ujo = 0.3. The curve a7 cuts the φ axis atϕm = 0.17862 showing their soliton nature.
In Figure 5, the profile of sagdeev potential function ψϕ against electrostatic potential ϕfor large amplitude solitons in presence of positronsχ=0.1701is denoted by a8 when the temperatures of positive σiand negative σjions are σi = 130 and σj = 125 with V = 1.69445,uio = 0.5, ujo = 0.3. In presence of positronsχ=0.1701 the curve a8cuts the ϕ axis at ϕm = 0.342575 showing the actual well shaped soliton nature.
Similarly it is further found that the profiles of sagdeev potential function ψϕ against electrostatic potential ϕfor large amplitude solitons in presence χ=0.1701of positronsdo not form the actual well shape for any value of ϕ within the limit for the solitary wave condition when the temperature of positive σiand negative σjions are σi = 125 and σj = 120 with V = 1.701, 1.801, 1.901& 1.99631, uio = 0.4, ujo = 0.2, χ = 0.1701, σp = 0.4101.
Figure 6 represents the Sagdeev potential profiles ψ(ϕ) against electrostatic potential ϕ for large amplitude solitary waves under the variation of the concentrations of negative ions njo in presence χ0of positrons.
Figure 6. Profiles of Sagdeev potential function ψ(ϕ) against ϕ for large amplitude solitary wavesin two temperature non-isothermalelectron plasma under the variation ofthe negative ion concentrationsnjo in presence of positrons for uio = 0.4, ujo = 0.2, σi = 120,σj = 125, χ = 0.1701,σp = 0.4101, µ = 0.15, ν = 0.85, bl = 0.15, bh = 0.4, β1 = 0.25, bl1 = 0.24, bh1 = 0.51, Z =1, Q = 1.912, V = 1.601,nio = 0.8299, 0.88 when njo = 0, 0.0501.Profiles of Sagdeev potential function ψ(ϕ) against ϕ for large amplitude solitary wavesin two temperature non-isothermalelectron plasma under the variation ofthe negative ion concentrationsnjo in presence of positrons for uio = 0.4, ujo = 0.2, σi = 120,σj = 125, χ = 0.1701,σp = 0.4101, µ = 0.15, ν = 0.85, bl = 0.15, bh = 0.4, β1 = 0.25, bl1 = 0.24, bh1 = 0.51, Z =1, Q = 1.912, V = 1.601,nio = 0.8299, 0.88 when njo = 0, 0.0501.
In presence of positronsχ=0.1701, the sagdeev potential profiles ψ(ϕ) against the electrostatic potential ϕfor large amplitude solitary waves are denoted by c1 for njo = 0 and c2 for njo = 0.0501when V = 1.601,uio = 0.4, ujo = 0.2,σi = 120,σj = 125. The curvesc1 and c2 cut the ϕ axis at ϕm = 0.297416 andϕm = 0.277660 respectively showing their well shaped soliton nature. This shows the effect of concentrations of negative ions on Sagdeev potential function ψ(ϕ)in presence of positrons.
Figure 7. Profiles of Sagdeev potential function ψ(ϕ) against ϕ for large amplitude solitary wavesin two temperature non-isothermal electron plasma under the variation of the negative ion concentrationsnjo in presence of positrons for uio = 0.4, ujo = 0.2, σi = 120,σj = 125, χ = 0.1701,σp = 0.4101,µ = 0.15, ν = 0.85, bl = 0.15, bh = 0.4, β1 = 0.25, bl1 = 0.24, bh1 = 0.51, Z =1, 0; Q = 1.912,V = 1.601, nio =0.84, 0.9 when njo= 0.0101, 0.0901.
In Figure 7, the sagdeev potential function ψ(ϕ) against the electrostatic potential ϕ for large amplitude solitary wavesin presence χ=0.1701of positronsare denoted byc3 for njo = 0.0101 and c4 for njo = 0.0901 whenV = 1.601,uio = 0.4, ujo = 0.2,σi = 120,σj = 125. It is evident from this figure that the curve c3 for njo = 0.0101 cuts the ϕ axis at a larger distance than the curve c4 for njo = 0.0901 with χ = 0.1701 where the curvec4 cuts the ϕ axis at ϕm = 0.259325. The Figures 6 and 7 show the characteristics of the sagdeev potential function under the variation of the concentration of negative ionsnjo in presence χ=0.1701of positrons.
In Figure 8, the profiles of Sagdeev potential function ψ(ϕ) against the electrostatic potential ϕ for large amplitude solitary waves are drawn under the variation of the concentrations of positrons(χ). For different values of the concentrations of positronsχ, the sagdeev potential function ψϕ cuts the ϕ axis at different values. The sagdeev potential function ψϕ at χ = 0.0801 denoted by c5 cuts the ϕ axis at ϕm = 0.213413 and at χ = 0.1201, the sagdeev potential function ψϕdenoted by c6 cuts the ϕ axis at ϕm = 0.246681. The curve c7 represents the sagdeev potential function ψϕcuts the ϕ axis at ϕm = 0.277660 for χ = 0.1701 which is larger than all other values.
Figure 8. Profiles of Sagdeev potential function ψ(ϕ) against ϕ for large amplitude solitary waves in two temperature non-isothermal electron plasma under the variation of the concentrationsχ of positrons for V = 1.601, uio = 0.4, ujo = 0.2, σi = 120,σj = 125,njo = 0.0501, nio =1.0501, 0.97, 0.93,0.88,σp = 0, 0.4101,µ = 0.15, ν = 0.85, bl = 0.15, bh = 0.4, β1 = 0.25, bl1 = 0.24, bh1 = 0.51, Z =1,Q = 1.912 when χ =0.0801, 0.1201,0.1701.
Figure 9. Profiles of Sagdeev potential function ψ(ϕ) against ϕ for large amplitude solitons in two temperature non-isothermal electrons under the variation of the temperature ratios σp of electrons and positrons for V = 1.601, uio = 0.4, ujo = 0.2, σi = 120,σj = 125 ,njo = 0.0501, nio =0.88, χ =0.1701,µ = 0.15, ν = 0.85, bl = 0.15, bh = 0.4, β1 = 0.25, bl1 = 0.24, bh1 = 0.51, Z =1,Q = 1.912 when σp = 0.4101, 1.Profiles of Sagdeev potential function ψ(ϕ) against ϕ for large amplitude solitons in two temperature non-isothermal electrons under the variation of the temperature ratios σp of electrons and positrons for V = 1.601, uio = 0.4, ujo = 0.2, σi = 120,σj = 125 ,njo = 0.0501, nio =0.88, χ =0.1701,µ = 0.15, ν = 0.85, bl = 0.15, bh = 0.4, β1 = 0.25, bl1 = 0.24, bh1 = 0.51, Z =1,Q = 1.912 when σp = 0.4101, 1.
In Figure 9, the Sagdeev potential profiles ψ(ϕ) against the electrostatic potential ϕ for large amplitude solitons are drawn under the variation of the different temperature ratios σpof electronTe and positron Tp. It is observed from Figures 9 and 10 that the Sagdeev potential profiles cut the ϕ axis at larger distances as long as the temperature ratiosσpofelectronTeand positron Tp is increasing. The Sagdeev potential profiles ψ(ϕ) against ϕfor solitary waves are denoted respectively by the curves c9 for σp = 0.4101, c10 for σp = 1 in Figure 9 and c12 for σp = 1.301,c13 for σp = 1.9501 in Figure 10. In Figure 9, the Sagdeev potential curves for actual well shaped solitary waves denoted by c9 forσp = 0.4101 cuts the ϕ axis at ϕm = 0.277660, c10 for σp = 1 cuts the ϕ axis at ϕm = 0.307871 but in Figure 10, forσp = 1.301 and 1.9501 no solitary waves for actual well shaped are found and thus it is concluded that for σp> 1 no proper solitary waves are found in two-temperature non-isothermal electron plasmas in presence of negative ions.
Figure 10. Profiles of Sagdeev potential function ψ(ϕ) against ϕ for large amplitude solitons in two temperature non-isothermal electrons under the variation of the temperature ratios of electrons and positronsσp for V = 1.601,uio = 0.4, ujo = 0.2, σi = 120,σj = 125,njo = 0.0501, nio =0.88,χ =0.1701, µ = 0.15, ν = 0.85, bl = 0.15, bh = 0.4, β1 = 0.25, bl1 = 0.24, bh1 = 0.51, Z =1, Q = 1.912 when σp = 1.301, 1.9501.Profiles of Sagdeev potential function ψ(ϕ) against ϕ for large amplitude solitons in two temperature non-isothermal electrons under the variation of the temperature ratios of electrons and positronsσp for V = 1.601,uio = 0.4, ujo = 0.2, σi = 120,σj = 125,njo = 0.0501, nio =0.88,χ =0.1701, µ = 0.15, ν = 0.85, bl = 0.15, bh = 0.4, β1 = 0.25, bl1 = 0.24, bh1 = 0.51, Z =1, Q = 1.912 when σp = 1.301, 1.9501.
In the next part, we are now presenting graphically the profiles of small amplitude double layers in presence χ=0.1701of positrons under the variation of some plasma parameters.
In Figure 11, the profiles of Sagdeev potential function ψ(ϕ) against the electrostatic potential ϕ for small amplitude double layers are drawn in presenceχ=0.1701 of positrons under the variation of the phase velocity (V) of solitary waves. In presence of positrons (χ = 0.1701), the Sagdeev potential profiles ψ(ϕ) against ϕ for small amplitude double layers are denoted by p1 for V = 1.6501, p2 for V = 1.6801. It is evident from the figure that for increasing values of V, the maximum values of the electrostatic potential (ϕdl) where the respective curves cut the ϕ axis are larger.
Figure 11. Profile of Sagdeev potential functionψ(ϕ) against ϕ for small amplitude double layers in presence of positrons under the variation of phase velocity (V) of solitary waves for uio = 0.4, ujo = 0.2, σi = 125,σj = 120,njo = 0.0501, nio =0.88, χ =0.1701,σp = 0.4101,µ = 0.15, ν = 0.85, bl = 0.15, bh = 0.4, β1 = 0.25, bl1 = 0.24, bh1 = 0.51, Z =1,Q = 1.912 when V = 1.6501, V = 1.6801.
Figure 12. Profile of Sagdeev potential function ψ(ϕ) against ϕ for small amplitude double layers in presence of positronsunder the variation of the concentration of negative ionsnjoforV = 1.6501, uio = 0.4, ujo = 0.2, σi = 125,σj = 120, χ =0.1701,σp = 0.4101,µ = 0.15, ν = 0.85, bl = 0.15, bh = 0.4, β1 = 0.25, bl1 = 0.24, bh1 = 0.51, Z =1,Q = 1.912,nio =0.87 when njo = 0.0401. Profile of Sagdeev potential function ψ(ϕ) against ϕ for small amplitude double layers in presence of positronsunder the variation of the concentration of negative ionsnjoforV = 1.6501, uio = 0.4, ujo = 0.2, σi = 125,σj = 120, χ =0.1701,σp = 0.4101,µ = 0.15, ν = 0.85, bl = 0.15, bh = 0.4, β1 = 0.25, bl1 = 0.24, bh1 = 0.51, Z =1,Q = 1.912,nio =0.87 when njo = 0.0401.
Figures 12 and 13 show the profiles of Sagdeev potential function ψ(ϕ) against the electrostatic potential ϕ for small amplitude double layers in presence of positronsχ=0.1701under the variation of the concentrations of negative ionsnjo.In Figure 12, when the concentration of negative ions is njo = 0.0401, the Sagdeev potential profile ψ(ϕ) against ϕ for small amplitude double layers is represented by the curve p3for χ = 0.1701 whereas in Figure 13, when the concentration of negative ions is njo = 0.0501, the Sagdeev potential profile ψ(ϕ) against ϕ for small amplitude double layers is denoted by the curve p4 for χ = 0.1701. In Figure 12, it is observed that the curve p3 in presence of positron (χ = 0.1701) cuts the ϕ axis at ϕdl = 0.020621 while in Figure 13, the Sagdeev potential profile ψ(ϕ) against ϕ for small amplitude double layers denoted by the curve p4 for χ = 0.1701 cuts the ϕ axis at ϕdl = 0.342005 when the concentration of negative ions is njo = 0.0501.
Figure 13. Profile of Sagdeev potential function ψ(ϕ) against ϕ for small amplitude double layersin presence of positronsunder the variation of the concentration of negative ionsnjoforV = 1.6501, uio = 0.4, ujo = 0.2, σi = 125,σj = 120, χ =0.1701, σp = 0.4101,µ = 0.15, ν = 0.85, bl = 0.15, bh = 0.4, β1 = 0.25, bl1 = 0.24, bh1 = 0.51, Z =1,Q = 1.912,nio =0.88 when njo = 0.0501.Profile of Sagdeev potential function ψ(ϕ) against ϕ for small amplitude double layersin presence of positronsunder the variation of the concentration of negative ionsnjoforV = 1.6501, uio = 0.4, ujo = 0.2, σi = 125,σj = 120, χ =0.1701, σp = 0.4101,µ = 0.15, ν = 0.85, bl = 0.15, bh = 0.4, β1 = 0.25, bl1 = 0.24, bh1 = 0.51, Z =1,Q = 1.912,nio =0.88 when njo = 0.0501.
Figure 14 shows the profiles of Sagdeev potential function ψ(ϕ) against the electrostatic potential ϕ for small amplitude double layers under the variation of the temperature ratios σp of electronsTe and positronsTp. The Sagdeev potential profiles ψ(ϕ) against ϕ for small amplitude double layers in presence of positron (χ = 0.1701)denoted by p6 for σp = 0.1501 and p7 for σp = 0.4101 cut the ϕ axis at ϕdl = 0.322136 and 0.342005 respectively. In this case, it is found that as σp increases ϕdl also increases.
Figure 14. Profiles of Sagdeev potential function ψ(ϕ) against ϕ for small amplitude double layers in presence of positrons under the variation of the temperature ratios σpof electrons and positronsfor V = 1.6501, uio = 0.4, ujo = 0.2, σi = 125,σj = 120,njo = 0.0501, nio =0.88, χ =0.1701, µ = 0.15, ν = 0.85, bl = 0.15, bh = 0.4, β1 = 0.25, bl1 = 0.24, bh1 = 0.51, Z =1,Q = 1.912 when σp = 0.1501, 0.4101.
From Figure 14, it is observed that in presence of positronχ=0.17, the Sagdeev potential profiles ψϕagainst ϕ for small amplitude double layers cut the ϕ axis at larger values of ϕdl for higher values of σp while for the smaller values of σp the respective Sagdeev potential curves for small amplitude double layerscut the ϕ axis at smaller values of ϕdl.
4.Conclusion
In this paper, the present author investigated the large amplitude ion-acoustic compressive solitary waves and small amplitude ion-acoustic compressive double layers in two-temperature non-isothermal electron plasmas consisting of warm negative ions, warm positive ions and warm positronsby Sagdeev pseudopotential method under the variation of different plasma parameters. In presence χ0of positrons, the nature of Sagdeev potential function ψϕ for large amplitude ion-acoustic compressive solitary waves are shown in Figures 1 to 10 under the variation of the mass ratios (Q) of negative to positive ions, phase velocities (V) of solitary waves, concentrationsnjoof negative ions,concentrations of positronsχ and temperature ratios σp of electronsTe and positronsTp. In Figures 11 to 14, the profiles of Sagdeev potential profiles ψϕagainst electrostatic potential ϕfor small amplitude double layers are presented graphically under the variation of the phase velocity (V) of solitary waves, concentration of negative ions njo and temperature ratios σp of electronsTe and positronsTp. In presence of positrons, the author studied and discussed the effect of positronsfor large amplitude solitons and small amplitude double layers. Generally solitons are important in understanding energy transport in space plasmas and have been considered in plasma–based devices for signal transmission without dissipation. On the other hand, double layers are relevant in the context of space weather phenomena and are important for understanding energy dissipation and particle acceleration mechanisms in astrophysical plasmas. The present study has been used in the experimental investigation of strong double layers for (Ar+,SF6-)plasma and will be helpful for the investigation of ion-acoustic waves in space and in laboratory experiments.
The author’s future plan is to solve the fully non-linear differential equations for relativistic warm positive and negative ions, two-temperature isothermal electrons and warm isothermal positrons to investigate the ion-acoustic compressive (rarefactive) solitary waves, double layers and supersolitons.
Abbreviations

SPM

Sagdeev Pseudopotential Method

Acknowledgments
The present author would like to thank Dr. S.N. Paul for his valuable suggestions and discussions in the preparation of this paper to its present form.
Funding
Thus this research work did not receive any specific grant from any funding agencies in the public, commercial, or not-for-profit sectors.
Conflicts of Interest
The author declares no conflicts of interest.
References
[1] M. K. Kalita and S. Bujarbarua, Can. J. Phys. 60, (1982) 392 - 396.
[2] S. G. Tagare and R. V. Reddy, J. Plasma Phys. 35, (1986) 219.
[3] S. G. Tagare and R. V. Reddy, Plasma Phys. and Controlled Fusion, 29(6), (1987) 671 – 676.
[4] S. Chattopadhyay, Brazilian Journal of Physics, 52(4), (2022) 117.
[5] R. V. Reddy and S. G. Tagare, J. Physical Soc. Japan, 56(12), (1987) 4329 – 4335
[6] S. Chattopadhyay and S. N. Paul, The African Review of Phys. 7:0033, (2012) 289 – 299.
[7] K. P. Das, S. R. Majumdar and S. N. Paul, Phys. Rev. E 51, (1995) 4796.
[8] S. Chattopadhyay, The African Review of Phys. 9: 0041, (2014) 317 – 331.
[9] B. N. Goswami and B. Buti,Phys. Letts. A, 57,2, (1976) 149 – 150.
[10] S. Chattopadhyay, Sri Lankan Journal of Phys. 29, (2019) 1 – 16.
[11] T. S. Gill, P. Bala, H. Kaur, N. S. Saini, S. Bansal and J. Kaur, The Euro. Phy. J. D31,(2004) 91.
[12] M. Tajiri and M. Tuda, J. Phys. Soc. Jpn. 54, (1985) 19.
[13] G. C. Das, B. Karmakar and S. N. Paul, IEEE Trans. Plasma Sci. 16(1), (1988) 22 – 26.
[14] M. K. Mishra, R. S. Chhabra and S. R. Sharma,J. Plasma Phys. 52(3),(1994) 409 – 429.
[15] S. Chakraborty, A. Roychowdhury and S. N. Paul, Inter. J. Theor. Phys. 32,(1993) 1465.
[16] S. G. Tagare, Phys. Plasmas, 7(3) (2000) 883 – 888.
[17] A. Y. Wong, D. L. Mamas and D. Arnush, Phys. Fluids 18(11) (1975) 1489 – 1493.
[18] S. Chattopadhyay, Sri Lankan Journal of Phys. 23(2), (2022) 93 – 124.
[19] S. Chattopadhyay, Jurnal Fizik Malaysia 43(1), (2022) 10214 – 10243.
[20] S. Chattopadhyay, Brazzilian Journal of Phys. 53, (2023) 6.
[21] G. C. Das, S. G. Tagare and J. Sarma, Planet Space Sci. 46(4), (1998) 417 – 424.
[22] R. Roychowdhury, G. C. Das and J. Sharma,Phys. Plasma 6(7), (1999) 2721 – 2726.
[23] K. S. Goswami and S. Bujarbarua, Phys. Lett. A, 108(3), (1985) 149 – 152.
[24] R. Bharuthram and P. K. Shukla, Phys. Fluids 29, (1986) 3214.
[25] L. L. Yadav and S. R. Sharma, Phys. Scr. 43(1), (1991) 106.
[26] A. N. Sekar and Y. C. Saxena, Plasma Phys. Controlled Fusion 27(2), (1985) 181.
[27] N. Hershkowitz, Space Sci. Rev. 41, (1985) 351 – 391.
[28] G. Hairapetian and R. L. Stenzel, Phys. Rev. Lett. 65, (1990) 175.
[29] G. C. Das and S. G. Tagare, Plasma Phys. 17(12), (1975) 1025.
[30] S. Watanabe, J. Phy. Soc. Japan 53(3), (1984) 950 – 956.
[31] S. G. Tagare, J. Plasma Phys. 36, (1986) 301.
[32] J. L. Cooney, M. T. Gavin and K. E. Lonngren, Phys. Fluids B 10, (1991) 2758 – 2766.
[33] M. K. Mishra, A. K. Arora and R. S. Chhabra, Phys. Rev. E 66, (2002) 046402.
[34] R. L. Merlino and J. J. Loomis,Phys. Fluids B 2, (1990) 2865 – 2867.
[35] S. Chattopadhyay, S. K. Bhattacharaya and S. N. Paul, Indian J. Phys. 76 B (1), (2002) 59 – 65.
[36] S. Chattopadhyay, S. N. Paul and D. Ray, Fizika A (Zagreb) 18, 3, (2009) 89 – 106.
[37] R. Z. Sagdeev, Reviews of Plasma Physics, Consultants Bureau, New York, 4, (1966) 23.
[38] K. K. Ghosh, D. Ray and S. N. Paul, Int. J. Theoretical Phys. 31(1), (1992) 75 – 80.
[39] G. C. Das and A. Nag, Assam Univ. J. Sci. Technol. 5, (2010) 169.
[40] M. Temerin, K. Cerny, W. Lotko and F. S. Mozer,Phys. Rev. Lett. 48, (1982) 1175.
[41] R. Bostrom, G. Gustafsson, B. Holback, G. Holmgren, H. Koskinen and P. Kintner,Phys. Rev. Lett. 61, (1988) 82.
[42] S. I. Popel, S. V. Vladimirov and P. K. Shukla, Phys. Plasmas 2, (1995) 716 – 719.
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    Chattopadhyay, S. (2024). Formation of Large Amplitude Solitons and Small Amplitude Double Layers in Two-temperature Non-isothermal Electron Plasma. American Journal of Physics and Applications, 12(6), 112-122. https://doi.org/10.11648/j.ajpa.20241206.11

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    Chattopadhyay, S. Formation of Large Amplitude Solitons and Small Amplitude Double Layers in Two-temperature Non-isothermal Electron Plasma. Am. J. Phys. Appl. 2024, 12(6), 112-122. doi: 10.11648/j.ajpa.20241206.11

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    Chattopadhyay S. Formation of Large Amplitude Solitons and Small Amplitude Double Layers in Two-temperature Non-isothermal Electron Plasma. Am J Phys Appl. 2024;12(6):112-122. doi: 10.11648/j.ajpa.20241206.11

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  • @article{10.11648/j.ajpa.20241206.11,
      author = {Sankar Chattopadhyay},
      title = {Formation of Large Amplitude Solitons and Small Amplitude Double Layers in Two-temperature Non-isothermal Electron Plasma},
      journal = {American Journal of Physics and Applications},
      volume = {12},
      number = {6},
      pages = {112-122},
      doi = {10.11648/j.ajpa.20241206.11},
      url = {https://doi.org/10.11648/j.ajpa.20241206.11},
      eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ajpa.20241206.11},
      abstract = {Propagation of large amplitude ion-acoustic solitary waves and small amplitude double layers have been investigated in a two-temperature non-isothermal electron plasma consisting of warm positive ions, warm negative ions and warm positrons by Sagdeev pseudopotential method (SPM). Small amplitude double layer solution (ϕDL) is also discussed theoretically in this paper for further investigation. Fully non-linear large amplitude compressive solitary waves and small amplitude compressive double layers are presented graphically by the corresponding figurs 1 – 14 under the variation of different values of the mass ratios (Q) of negative to positive ions, phase velocities (V) of solitary waves, negative ion concentrations (njo), positron densities (χ) and temperature ratios (σp) of electrons (Te) and positrons (Tp). Consequently this large amplitude electrostatic solitary waves and small amplitude electrostatic double layers in complex plasmas have broad applications in space plasma Physics, Astrophysics, Fusion technology, Plasma – based devices and Fundamental wave research, offering tools for exploring wave-particle interactions, stability and energy transfer in multi-species plasmas.
    },
     year = {2024}
    }
    

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  • TY  - JOUR
    T1  - Formation of Large Amplitude Solitons and Small Amplitude Double Layers in Two-temperature Non-isothermal Electron Plasma
    AU  - Sankar Chattopadhyay
    Y1  - 2024/12/30
    PY  - 2024
    N1  - https://doi.org/10.11648/j.ajpa.20241206.11
    DO  - 10.11648/j.ajpa.20241206.11
    T2  - American Journal of Physics and Applications
    JF  - American Journal of Physics and Applications
    JO  - American Journal of Physics and Applications
    SP  - 112
    EP  - 122
    PB  - Science Publishing Group
    SN  - 2330-4308
    UR  - https://doi.org/10.11648/j.ajpa.20241206.11
    AB  - Propagation of large amplitude ion-acoustic solitary waves and small amplitude double layers have been investigated in a two-temperature non-isothermal electron plasma consisting of warm positive ions, warm negative ions and warm positrons by Sagdeev pseudopotential method (SPM). Small amplitude double layer solution (ϕDL) is also discussed theoretically in this paper for further investigation. Fully non-linear large amplitude compressive solitary waves and small amplitude compressive double layers are presented graphically by the corresponding figurs 1 – 14 under the variation of different values of the mass ratios (Q) of negative to positive ions, phase velocities (V) of solitary waves, negative ion concentrations (njo), positron densities (χ) and temperature ratios (σp) of electrons (Te) and positrons (Tp). Consequently this large amplitude electrostatic solitary waves and small amplitude electrostatic double layers in complex plasmas have broad applications in space plasma Physics, Astrophysics, Fusion technology, Plasma – based devices and Fundamental wave research, offering tools for exploring wave-particle interactions, stability and energy transfer in multi-species plasmas.
    
    VL  - 12
    IS  - 6
    ER  - 

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