Experimental evidence of increased electron temperature, plasma potential, and ion energy near an ICRF antenna Faraday shield

PDF Version Also Available for Download.

Description

Plasma properties and ion energies have been measured near the surface of the Faraday shield for an ICRF antenna to determine the effect of rf fields on the energy of ions bombarding the shield surface. A resonant loop antenna with a two-tier Faraday shield was used on the rf Test Facility at Oak Ridge National Laboratory. The ECH plasma was produced by a 10.6 GHz klystron and had a central density of {approximately}10{sup 11} cm{sup {minus}3} and an electron temperature of 5--10 eV. The static magnetic field at the antenna was {approximately}2 kG. A capacitive probe was used to measure ... continued below

Physical Description

Pages: (14 p)

Creation Information

Caughman, J.B.O. II; Ruzic, D.N.; Hoffman, D.J. (Illinois Univ., Urbana, IL (USA) & Oak Ridge National Lab., TN (USA)) January 1, 1989.

Context

This article 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 article can be viewed below.

Who

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

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 article. Follow the links below to find similar items on the Digital Library.

Description

Plasma properties and ion energies have been measured near the surface of the Faraday shield for an ICRF antenna to determine the effect of rf fields on the energy of ions bombarding the shield surface. A resonant loop antenna with a two-tier Faraday shield was used on the rf Test Facility at Oak Ridge National Laboratory. The ECH plasma was produced by a 10.6 GHz klystron and had a central density of {approximately}10{sup 11} cm{sup {minus}3} and an electron temperature of 5--10 eV. The static magnetic field at the antenna was {approximately}2 kG. A capacitive probe was used to measure the time-varying floating potential and a Langmuir probe was used to measure the time-averaged electron temperature, density, and dc floating potential. Both probes were scanned in front of the antenna. Ion energies were measured with a gridded energy analyzer located next to the antenna. The time-varying floating potential followed the magnetic field pattern of the antenna, indicating that the electromagnetic field is responsible for the potential formation. Potential values of 300 V p-p have been measured. Electron temperatures increased with rf power and reached values {ge} 60 eV for an rf power of {approximately}25 kW. The energy of ions hitting a grounded surface also increased with rf power and exceeded 300 eV at {approximately}25 kW of rf power (compared with energies of 5--15 eV with no rf power). The increase in ion energy can be at least partially explained by an increase in the sheath potential, which in turn is caused by an increase in the electron temperature. 9 refs., 4 figs.

Physical Description

Pages: (14 p)

Notes

NTIS, PC A03/MF A01; OSTI; INIS; GPO Dep.

Source

  • IAEA technical committee meeting on ICRH/edge physics, Munich (Germany, F.R.), 2-5 Oct 1989

Language

Item Type

Identifier

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

  • Other: DE90001959
  • Report No.: CONF-8910225-4
  • Grant Number: AC05-84OR21400
  • Office of Scientific & Technical Information Report Number: 5588540
  • Archival Resource Key: ark:/67531/metadc1093626

Collections

This article 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 article?

When

Dates and time periods associated with this article.

Creation Date

  • January 1, 1989

Added to The UNT Digital Library

  • Feb. 10, 2018, 10:06 p.m.

Description Last Updated

  • Feb. 16, 2018, 6:01 p.m.

Usage Statistics

When was this article last used?

Congratulations! It looks like you are the first person to view this item online.

Interact With This Article

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

Citations, Rights, Re-Use

Caughman, J.B.O. II; Ruzic, D.N.; Hoffman, D.J. (Illinois Univ., Urbana, IL (USA) & Oak Ridge National Lab., TN (USA)). Experimental evidence of increased electron temperature, plasma potential, and ion energy near an ICRF antenna Faraday shield, article, January 1, 1989; Tennessee. (digital.library.unt.edu/ark:/67531/metadc1093626/: accessed April 19, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.