Diagnostic Development for ST Plasmas on NSTX

PDF Version Also Available for Download.

Description

Spherical tokamaks (STs) have much lower aspect ratio (a/R) and lower toroidal magnetic field, relative to tokamaks and stellarators. This paper will highlight some of the challenges and opportunities these features pose in the diagnosis of ST plasmas on the National Spherical Torus Experiment (NSTX), and discuss some of the corresponding diagnostic development that is underway. The low aspect ratio necessitates a small center stack, with tight space constraints and large thermal excursions, complicating the design of magnetic sensors in this region. The toroidal magnetic field on NSTX is less than or equal to 0.6 T, making it impossible to ... continued below

Physical Description

1 MB pages

Creation Information

Johnson, D. & Team, NSTX June 16, 2003.

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

Spherical tokamaks (STs) have much lower aspect ratio (a/R) and lower toroidal magnetic field, relative to tokamaks and stellarators. This paper will highlight some of the challenges and opportunities these features pose in the diagnosis of ST plasmas on the National Spherical Torus Experiment (NSTX), and discuss some of the corresponding diagnostic development that is underway. The low aspect ratio necessitates a small center stack, with tight space constraints and large thermal excursions, complicating the design of magnetic sensors in this region. The toroidal magnetic field on NSTX is less than or equal to 0.6 T, making it impossible to use ECE as a good monitor of electron temperature. A promising new development for diagnosing electron temperature is electron Bernstein wave (EBW) radiometry, which is currently being pursued on NSTX. A new high-resolution charge exchange recombination spectroscopy system is being installed. Since non-inductive current initiation and sustainment ar e top-level NSTX research goals, measurements of the current profile J(R) are essential to many planned experiments. On NSTX several modifications are planned to adapt the MSE technique to lower field, and two novel MSE systems are being prototyped. Several high speed 2-D imaging techniques are being developed, for viewing both visible and x-ray emission. The toroidal field is comparable to the poloidal field at the outside plasma edge, producing a large field pitch (>50{sup o}) at the outer mid-plane. The large shear in pitch angle makes some fluctuation diagnostics like beam emission spectroscopy very difficult, while providing a means of achieving spatial localization for microwave scattering investigations of high-k turbulence, which are predicted to be virulent for NSTX plasmas. A brief description of several of these techniques will be given in the context of the current NSTX diagnostic set.

Physical Description

1 MB pages

Notes

INIS; OSTI as DE00814679

Source

  • Other Information: PBD: 16 Jun 2003

Language

Item Type

Identifier

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

  • Report No.: PPPL-3822
  • Grant Number: AC02-76CH03073
  • DOI: 10.2172/814679 | External Link
  • Office of Scientific & Technical Information Report Number: 814679
  • Archival Resource Key: ark:/67531/metadc733616

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

  • June 16, 2003

Added to The UNT Digital Library

  • Oct. 18, 2015, 6:40 p.m.

Description Last Updated

  • April 15, 2016, 8:36 p.m.

Usage Statistics

When was this report last used?

Yesterday: 0
Past 30 days: 0
Total Uses: 8

Interact With This Report

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

Citations, Rights, Re-Use

Johnson, D. & Team, NSTX. Diagnostic Development for ST Plasmas on NSTX, report, June 16, 2003; Princeton, New Jersey. (digital.library.unt.edu/ark:/67531/metadc733616/: accessed December 18, 2017), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.