# Nonlinear propagation of ion-acoustic waves in electron-positron-ion plasma with trapped electrons

## Abstract

A theoretical investigation has been made for ion-acoustic waves in an unmagnetized electron-positron-ion plasma. A more realistic situation in which plasma consists of a negatively charged ion fluid, free positrons, and trapped as well as free electrons is considered. The properties of stationary structures are studied by the reductive perturbation method, which is valid for small but finite amplitude limit, and by pseudopotential approach, which is valid for large amplitude. With an appropriate modified form of the electron number density, two new equations for the ion dynamics have been found. When deviations from isothermality are finite, the modified Korteweg-deVries equation has been found, and for the case that deviations from isothermality are small, calculations lead to a generalized Korteweg-deVries equation. It is shown from both weakly and highly nonlinear analysis that the presence of the positrons may allow solitary waves to exist. It is found that the effect of the positron density changes the maximum value of the amplitude and M (Mach number) for which solitary waves can exist. The present theory is applicable to analyze arbitrary amplitude ion-acoustic waves associated with positrons which may occur in space plasma.

- Authors:

- Faculty of Physics, Tabriz University, Tabriz 51664 (Iran, Islamic Republic of)
- (Iran, Islamic Republic of)

- Publication Date:

- OSTI Identifier:
- 20782435

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Physics of Plasmas; Journal Volume: 13; Journal Issue: 1; Other Information: DOI: 10.1063/1.2158148; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; AMPLITUDES; ELECTRON DENSITY; ION ACOUSTIC WAVES; IONS; KORTEWEG-DE VRIES EQUATION; MACH NUMBER; NONLINEAR PROBLEMS; PERTURBATION THEORY; PLASMA; PLASMA DENSITY; POSITRONS; SOLITONS; TRAPPED ELECTRONS; TRAPPING

### Citation Formats

```
Alinejad, H., Sobhanian, S., Mahmoodi, J., and Physics Department, University of Qom, Qom.
```*Nonlinear propagation of ion-acoustic waves in electron-positron-ion plasma with trapped electrons*. United States: N. p., 2006.
Web. doi:10.1063/1.2158148.

```
Alinejad, H., Sobhanian, S., Mahmoodi, J., & Physics Department, University of Qom, Qom.
```*Nonlinear propagation of ion-acoustic waves in electron-positron-ion plasma with trapped electrons*. United States. doi:10.1063/1.2158148.

```
Alinejad, H., Sobhanian, S., Mahmoodi, J., and Physics Department, University of Qom, Qom. Sun .
"Nonlinear propagation of ion-acoustic waves in electron-positron-ion plasma with trapped electrons". United States.
doi:10.1063/1.2158148.
```

```
@article{osti_20782435,
```

title = {Nonlinear propagation of ion-acoustic waves in electron-positron-ion plasma with trapped electrons},

author = {Alinejad, H. and Sobhanian, S. and Mahmoodi, J. and Physics Department, University of Qom, Qom},

abstractNote = {A theoretical investigation has been made for ion-acoustic waves in an unmagnetized electron-positron-ion plasma. A more realistic situation in which plasma consists of a negatively charged ion fluid, free positrons, and trapped as well as free electrons is considered. The properties of stationary structures are studied by the reductive perturbation method, which is valid for small but finite amplitude limit, and by pseudopotential approach, which is valid for large amplitude. With an appropriate modified form of the electron number density, two new equations for the ion dynamics have been found. When deviations from isothermality are finite, the modified Korteweg-deVries equation has been found, and for the case that deviations from isothermality are small, calculations lead to a generalized Korteweg-deVries equation. It is shown from both weakly and highly nonlinear analysis that the presence of the positrons may allow solitary waves to exist. It is found that the effect of the positron density changes the maximum value of the amplitude and M (Mach number) for which solitary waves can exist. The present theory is applicable to analyze arbitrary amplitude ion-acoustic waves associated with positrons which may occur in space plasma.},

doi = {10.1063/1.2158148},

journal = {Physics of Plasmas},

number = 1,

volume = 13,

place = {United States},

year = {Sun Jan 15 00:00:00 EST 2006},

month = {Sun Jan 15 00:00:00 EST 2006}

}