A study of a parallel mode launch into a magnetic beach

Author

Keil, Douglas L. ; Bettenhausen, Michael H. ; Hershkowitz, Noah

Author_Institution

Wisconsin Univ., Madison, WI, USA

Volume

21

Issue

3

fYear

1993

fDate

6/1/1993 12:00:00 AM

Firstpage

329

Lastpage

336

Abstract

A parallel mode launch in the electron cyclotron range of frequencies is performed on axis in the east end cell of the Phaedrus-B tandem mirror. Propagation of the energy launched toward a magnetic beach in a radially hollow density profile was studied experimentally. A strong refractive dispersal of the launched energy was observed and shown to be in good agreement with a WKB-type ray tracing model using a cold plasma Appleton-Hartree dispersion relation. Measurements of plasma density and electron temperature indicate that the use of this dispersion relation is well justified. These results are compared with additional ray tracing studies for radially hollow and nonhollow, high ( f_launch<f_p) and low (f _launch>f_p) density models. For the experimental conditions examined, a reversal of refractive behavior is shown to exist as the energy propagates from a low density (f_launch>f_p) region to a high density (f_launch<f_p) region

Keywords

dispersion relations; electromagnetic wave propagation in plasma; magnetic mirrors; plasma density; plasma radiofrequency heating; plasma temperature; Phaedrus-B tandem mirror; WKB-type ray tracing model; cold plasma Appleton-Hartree dispersion relation; electron cyclotron range of frequencies; electron temperature; magnetic beach; parallel mode launch; plasma density; radially hollow density profile; ray tracing; refractive behavior; refractive dispersal; wave propagation; Cyclotrons; Density measurement; Dispersion; Electrons; Frequency; Mirrors; Plasma density; Plasma measurements; Plasma temperature; Ray tracing;

fLanguage

English

Journal_Title

Plasma Science, IEEE Transactions on

Publisher

ieee

ISSN

0093-3813

Type

jour

DOI

10.1109/27.277559

Filename

277559