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Title: Interpretation of PISCES -- A RF antenna system experimental results

Abstract

The paper describes experimental data from rf coupling experiments using one to four coil antenna arrays that encircle a linear magnetized plasma column. Experimental results using single turn coil that produce symmetric (i.e. m = 0), dipole (m = 1), and radial rf magnetic fields for coupling to ion waves are compared. By operating without a Faraday shield, it was observed for the first time that the plasma resistive load seen by these different antenna types tends to increase with the number of turns to at least the second power. A four-turn m = 0 coil experienced a record 3--5 {Omega} loading, corresponding to over 90% power coupling to the plasma. A four-turn m = 1 coil experienced up to 1--1.5 {Omega} loading, also higher than previous observations. First time observations using a two coil array of m = 0 coil are also reported. As predicted, the loading decreases with increasing phase between coil from 0{degree} to 180{degree}. Experiments using four coil arrays were difficult to optimize and interpret primarily due to complexity of the manual tuning. To facilitate this optimization in the future, a proposed feedback control system that automatically matches load variations between 0.2 and 10 {Omega} ismore » described.« less

Authors:
;  [1];  [2]
  1. General Atomics, San Diego, CA (United States)
  2. Univ. of California, San Diego, CA (United States)
Publication Date:
Research Org.:
General Atomics, San Diego, CA (United States)
Sponsoring Org.:
USDOE Office of Energy Research, Washington, DC (United States)
OSTI Identifier:
468568
Report Number(s):
GA-A22209; CONF-950905-52
ON: DE97004591; TRN: 97:010015
DOE Contract Number:  
AC03-89ER51114
Resource Type:
Technical Report
Resource Relation:
Conference: 16. IEEE/NPSS symposium on fusion engineering, Champaign, IL (United States), 1-5 Oct 1995; Other Information: PBD: Oct 1995
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION; RF SYSTEMS; ICR HEATING; THERMONUCLEAR DEVICES; EXPERIMENTAL DATA; OPERATION; CONTROL SYSTEMS; FEEDBACK

Citation Formats

Rothweil, D A, Phelps, D A, and Doerner, R. Interpretation of PISCES -- A RF antenna system experimental results. United States: N. p., 1995. Web. doi:10.2172/468568.
Rothweil, D A, Phelps, D A, & Doerner, R. Interpretation of PISCES -- A RF antenna system experimental results. United States. https://doi.org/10.2172/468568
Rothweil, D A, Phelps, D A, and Doerner, R. Sun . "Interpretation of PISCES -- A RF antenna system experimental results". United States. https://doi.org/10.2172/468568. https://www.osti.gov/servlets/purl/468568.
@article{osti_468568,
title = {Interpretation of PISCES -- A RF antenna system experimental results},
author = {Rothweil, D A and Phelps, D A and Doerner, R},
abstractNote = {The paper describes experimental data from rf coupling experiments using one to four coil antenna arrays that encircle a linear magnetized plasma column. Experimental results using single turn coil that produce symmetric (i.e. m = 0), dipole (m = 1), and radial rf magnetic fields for coupling to ion waves are compared. By operating without a Faraday shield, it was observed for the first time that the plasma resistive load seen by these different antenna types tends to increase with the number of turns to at least the second power. A four-turn m = 0 coil experienced a record 3--5 {Omega} loading, corresponding to over 90% power coupling to the plasma. A four-turn m = 1 coil experienced up to 1--1.5 {Omega} loading, also higher than previous observations. First time observations using a two coil array of m = 0 coil are also reported. As predicted, the loading decreases with increasing phase between coil from 0{degree} to 180{degree}. Experiments using four coil arrays were difficult to optimize and interpret primarily due to complexity of the manual tuning. To facilitate this optimization in the future, a proposed feedback control system that automatically matches load variations between 0.2 and 10 {Omega} is described.},
doi = {10.2172/468568},
url = {https://www.osti.gov/biblio/468568}, journal = {},
number = ,
volume = ,
place = {United States},
year = {1995},
month = {10}
}