Spatially limited ion acoustic wave activity in low-pressure helicon discharges

Date

2004

Authors

Corr, Cormac
Plihon, N.
Chabert, Pascal
Sutherland, Orson
Boswell, Roderick

Journal Title

Journal ISSN

Volume Title

Publisher

American Institute of Physics (AIP)

Abstract

Ion acoustic wave phenomena are studied and compared in two low-pressure argon discharges created by helicon sources. The wave amplitudes are spatially localized near the edge of a plasma column as the amplitudes of the "mirror waves" that are separated from the helicon source frequency by the ion wave frequency. Dependencies of the ion wave on radial position, pressure, input power, and magnetic field are investigated. Measurements of the wavelength show that the wave is traveling azimuthally at approximately the ion sound speed in the direction of electron gyration. Although the wave spectra are indicative of a parametric decay phenomenon, it seems more likely that the radial plasma pressure gradient drives an ion acoustic instability which then modulates the helicon source.

Description

Keywords

Citation

Source

Physics of Plasmas

Type

Journal article

Book Title

Entity type

Access Statement

License Rights

DOI

10.1063/1.1785790

Restricted until

2037-12-31