Radio frequency current drive considerations for small aspect ratio tori

PDF Version Also Available for Download.

Description

Noninductive current drive is required during plasma initiation and for current sustainment in the National Spherical Torus Experiment (NSTX). In this paper, the physics of high harmonic fast waves (HHFW) and the design of an antenna system for NSTX are considered using numerical models. For high current discharges in NSTX, the static magnetic field component in the poloidal direction varies widely during the discharge and can become comparable to the toroidal component in NSTX. Therefore, they calculate the plasma loading for a broad range of antenna and plasma geometries in a three-dimensional model, so that the results can be used ... continued below

Physical Description

35 p.

Creation Information

Carter, M.D.; Jaeger, E.F.; Strickler, D.J.; Ryan, P.M.; Swain, D.W. & Batchelor, D.B. July 1, 1998.

Context

This report is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided by UNT Libraries Government Documents Department to Digital Library, a digital repository hosted by the UNT Libraries. More information about this report can be viewed below.

Who

People and organizations associated with either the creation of this report or its content.

Sponsor

Publisher

Provided By

UNT Libraries Government Documents Department

Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.

Contact Us

What

Descriptive information to help identify this report. Follow the links below to find similar items on the Digital Library.

Description

Noninductive current drive is required during plasma initiation and for current sustainment in the National Spherical Torus Experiment (NSTX). In this paper, the physics of high harmonic fast waves (HHFW) and the design of an antenna system for NSTX are considered using numerical models. For high current discharges in NSTX, the static magnetic field component in the poloidal direction varies widely during the discharge and can become comparable to the toroidal component in NSTX. Therefore, they calculate the plasma loading for a broad range of antenna and plasma geometries in a three-dimensional model, so that the results can be used to influence the antenna design. Two-dimensional calculations of the wave propagation and absorption in the core plasma indicate that the theoretical current drive efficiency for HHFW can be high, and a general survey of parameters gives a good target for the antenna design. The current drive efficiency calculation is sensitive to the equilibrium model because finite beta effects can substantially alter the calculation of the trapped particle fraction. Traditional methods of toroidally phasing an antenna array as well as poloidal phasing are studied to optimize the current drive efficiency for a range of equilibria. Non-zero poloidal mode excitation is also found to affect the antenna performance and flexibility. Performance expectations for a preliminary antenna design are given.

Physical Description

35 p.

Notes

INIS; OSTI as DE99000346

Source

  • Other Information: PBD: Jul 1998

Language

Item Type

Identifier

Unique identifying numbers for this report in the Digital Library or other systems.

  • Other: DE99000346
  • Report No.: ORNL/TM--13576
  • Grant Number: AC05-96OR22464
  • DOI: 10.2172/677115 | External Link
  • Office of Scientific & Technical Information Report Number: 677115
  • Archival Resource Key: ark:/67531/metadc709282

Collections

This report is part of the following collection of related materials.

Office of Scientific & Technical Information Technical Reports

Reports, articles and other documents harvested from the Office of Scientific and Technical Information.

Office of Scientific and Technical Information (OSTI) is the Department of Energy (DOE) office that collects, preserves, and disseminates DOE-sponsored research and development (R&D) results that are the outcomes of R&D projects or other funded activities at DOE labs and facilities nationwide and grantees at universities and other institutions.

What responsibilities do I have when using this report?

When

Dates and time periods associated with this report.

Creation Date

  • July 1, 1998

Added to The UNT Digital Library

  • Sept. 12, 2015, 6:31 a.m.

Description Last Updated

  • Jan. 20, 2016, 3:42 p.m.

Usage Statistics

When was this report last used?

Yesterday: 0
Past 30 days: 0
Total Uses: 3

Interact With This Report

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

International Image Interoperability Framework

IIF Logo

We support the IIIF Presentation API

Carter, M.D.; Jaeger, E.F.; Strickler, D.J.; Ryan, P.M.; Swain, D.W. & Batchelor, D.B. Radio frequency current drive considerations for small aspect ratio tori, report, July 1, 1998; Tennessee. (digital.library.unt.edu/ark:/67531/metadc709282/: accessed August 20, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.