Gap eigenmode of radially localized helicon waves in a periodic structure

Date

2013

Authors

Chang, Lei
Breizman, Boris
Hole, Matthew

Journal Title

Journal ISSN

Volume Title

Publisher

Institute of Physics Publishing

Abstract

An ElectroMagnetic Solver (Chen et al 2006 Phys. Plasmas 13 123507) is employed to model a spectral gap and a gap eigenmode in a periodic structure in the whistler frequency range. A radially localized helicon mode (Breizman and Arefiev 2000 Phys. Rev. Lett. 84 3863) is considered. We demonstrate that the computed gap frequency and gap width agree well with a theoretical analysis, and find a discrete eigenmode inside the gap by introducing a defect to the system's periodicity. The axial wavelength of the gap eigenmode is close to twice the system's periodicity, which is consistent with Bragg's law. Such an eigenmode could be excited by energetic electrons, similar to the excitation of toroidal Alfvén eigenmodes by energetic ions in tokamaks. Experimental identification of this mode is conceivable on the large plasma device (Gekelman et al 1991 Rev. Sci. Instrum. 62 2875).

Description

Keywords

Keywords: Bragg's law; Eigen modes; Electromagnetic solvers; Energetic electron; Energetic ion; Experimental identification; Gap widths; Helicon waves; Spectral gap; Whistler frequency range; Magnetoplasma; Periodic structures; Helicons

Citation

Source

Plasma Physics and Controlled Fusion

Type

Journal article

Book Title

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DOI

10.1088/0741-3335/55/2/025003

Restricted until

2037-12-31