Three-dimensional effects for radio frequency antenna modeling

Conference · Sat Oct 15 00:00:00 EDT 1994 · AIP Conference Proceedings (American Institute of Physics); (United States)

OSTI ID:7260986

Carter, M D; Batchelor, D B; Stallings, D C ^[1]

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1. Oak Ridge National Laboratory, Oak Ridge, Tennessee 37821-8071 (United States)

Electromagnetic field calculations for radio frequency (rf) antennas in two dimensions (2-D) neglect finite antenna length effects as well as the feeders leading to the main current strap. The 2-D calculations predict that the return currents in the sidewalls of the antenna structure depend strongly on the plasma parameters, but this prediction is suspect because of experimental evidence. To study the validity of the 2-D approximation, the Multiple Antenna Implementation System (MAntIS) has been used to perform three-dimensional (3-D) modeling of the power spectrum, plasma loading, and inductance for a relevant loop antenna design. Effects on antenna performance caused by feeders to the main current strap and conducting sidewalls are considered. The modeling shows that the feeders affect the launched power spectrum in an indirect way by forcing the driven rf current to return in the antenna structure rather than the plasma, as in the 2-D model. It has also been found that poloidal dependencies in the plasma impedance matrix can reduce the loading predicted from that predicted in the 2-D model. For some plasma parameters, the combined 3-D effects can lead to a reduction in the predicted loading by as much as a factor of 2 from that given by the 2-D model, even with end-effect corrections for the 2-D model.

• DOE Contract Number: AC05-84OR21400
• OSTI ID: 7260986
• Report Number(s): CONF-9304112-; CODEN: APCPCS; TRN: 94-014236
• Journal Information: AIP Conference Proceedings (American Institute of Physics); (United States), Vol. 289:1; Conference: 10. topical conference on radio frequency power in plasmas, Boston, MA (United States), 1-3 Apr 1993; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ANTENNAS
MATHEMATICAL MODELS
RF SYSTEMS
COMPARATIVE EVALUATIONS
COMPUTER CODES
DESIGN
ELECTRIC CURRENTS
MAGNETIC FIELDS
PLASMA
RADIOWAVE RADIATION
THREE-DIMENSIONAL CALCULATIONS
TOROIDAL CONFIGURATION
TWO-DIMENSIONAL CALCULATIONS
ANNULAR SPACE
CLOSED CONFIGURATIONS
CONFIGURATION
CURRENTS
ELECTRICAL EQUIPMENT
ELECTROMAGNETIC RADIATION
EQUIPMENT
EVALUATION
MAGNETIC FIELD CONFIGURATIONS
RADIATIONS
SPACE
700350* - Plasma Production
Heating
Current Drive
& Interactions- (1992-)