# Cutoff frequency of toroidal plasma waveguide

## Abstract

The cutoff frequencies of E and H-modes of empty and plasma filled toroidal waveguides are evaluated. The effects of space curvature and plasma density on cutoff frequencies for both modes are investigated. Using a suitable variable change, a scalar wave equation in the direction of propagation was obtained. The study indicates that the curvature in the direction of wave propagation in toroidal waveguide has an analogous effect as a straight waveguide filled with anisotropic media. The Rayleigh-Schrodinger perturbation method was employed to solve for cutoff frequencies in the first order of approximation. In the limit of small space curvature, the toroidal waveguide cutoff frequencies for both E and H-modes approach those of TM and TE modes of empty cylindrical waveguide with a radius equal to toroidal waveguide minor radius. The analysis shows that the curvature in the direction of propagation in toroidal waveguides leads to the removal of the degeneracy between E and H-modes.

- Authors:

- Department of Physics, University of Tehran, Tehran 14399 (Iran, Islamic Republic of)

- Publication Date:

- OSTI Identifier:
- 22408074

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Physics of Plasmas; Journal Volume: 22; Journal Issue: 2; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ANISOTROPY; CYLINDRICAL CONFIGURATION; DISTURBANCES; H-MODE PLASMA CONFINEMENT; PLASMA DENSITY; TOROIDAL CONFIGURATION; WAVE EQUATIONS; WAVEGUIDES

### Citation Formats

```
Zakeri-Khatir, H., and Aghamir, F. M.
```*Cutoff frequency of toroidal plasma waveguide*. United States: N. p., 2015.
Web. doi:10.1063/1.4907795.

```
Zakeri-Khatir, H., & Aghamir, F. M.
```*Cutoff frequency of toroidal plasma waveguide*. United States. doi:10.1063/1.4907795.

```
Zakeri-Khatir, H., and Aghamir, F. M. Sun .
"Cutoff frequency of toroidal plasma waveguide". United States.
doi:10.1063/1.4907795.
```

```
@article{osti_22408074,
```

title = {Cutoff frequency of toroidal plasma waveguide},

author = {Zakeri-Khatir, H. and Aghamir, F. M.},

abstractNote = {The cutoff frequencies of E and H-modes of empty and plasma filled toroidal waveguides are evaluated. The effects of space curvature and plasma density on cutoff frequencies for both modes are investigated. Using a suitable variable change, a scalar wave equation in the direction of propagation was obtained. The study indicates that the curvature in the direction of wave propagation in toroidal waveguide has an analogous effect as a straight waveguide filled with anisotropic media. The Rayleigh-Schrodinger perturbation method was employed to solve for cutoff frequencies in the first order of approximation. In the limit of small space curvature, the toroidal waveguide cutoff frequencies for both E and H-modes approach those of TM and TE modes of empty cylindrical waveguide with a radius equal to toroidal waveguide minor radius. The analysis shows that the curvature in the direction of propagation in toroidal waveguides leads to the removal of the degeneracy between E and H-modes.},

doi = {10.1063/1.4907795},

journal = {Physics of Plasmas},

number = 2,

volume = 22,

place = {United States},

year = {Sun Feb 15 00:00:00 EST 2015},

month = {Sun Feb 15 00:00:00 EST 2015}

}