Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Analysis of ion cyclotron heating and current drive at omega approximate to 2 omega(cH) for sawtooth control in JET plasmas
Show others and affiliations
2002 (English)In: Plasma Physics and Controlled Fusion, ISSN 0741-3335, E-ISSN 1361-6587, Vol. 44, no 8, 1521-1542 p.Article in journal (Refereed) Published
Abstract [en]

Ion cyclotron heating and current drive at omega approximate to 2omega(cH) in JET deuterium plasmas with a hydrogen concentration n(H)/(n(D)+n(H)) in the range of 5-15% are analysed, comparing results of numerical computer modelling with experiments. Second harmonic hydrogen damping is found to be maximized by placing the resonance on the, low-field side (LFS) of the torus, which minimizes competing direct electron damping and parasitic high-harmonic D damping in the presence of D beams. The shape of the calculated current perturbation and the radial localization of the heating power density for the LFS resonance are consistent with the experimentally observed evolution of the sawtooth period when the resonance layer moves near the q = 1 surface. Since the calculated driven current is dominated by a current of diamagnetic type caused by finite orbit widths of trapped resonating ions, it is not too sensitive to the ICRF phasing. Control of sawteeth with ion cyclotron current drive using the LFS omega approximate to 2omega(cH) resonance in the present experimental conditions can thus be best obtained by varying the resonance location rather than the ICRF phasing. Due to differences in fast ion orbits, collisional electron heating and fast ion pressure profiles are significantly more peaked for a LFS resonance than for a high-field side (HFS) resonance. For the HFS omega approximate to 2omega(cH) resonance, an enhanced neutron rate is observed in the presence of D beam ions, which is consistent with parasitic D damping at the omega approximate to 2omega(cD) resonance in the plasma centre.

Place, publisher, year, edition, pages
2002. Vol. 44, no 8, 1521-1542 p.
Keyword [en]
internal kink stabilization, neutral injection, toroidal plasmas, alpha-particles, heated plasmas, tokamaks, icrf, deposition, transport, sawteeth
Identifiers
URN: urn:nbn:se:kth:diva-21897DOI: 10.1088/0741-3335/44/8/307ISI: 000178020200009OAI: oai:DiVA.org:kth-21897DiVA: diva2:340595
Note
QC 20100525Available from: 2010-08-10 Created: 2010-08-10 Last updated: 2017-12-12Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Authority records BETA

Johnson, Thomas J.

Search in DiVA

By author/editor
Hellsten, Torbjörn A. K.Johnson, Thomas J.
By organisation
Alfvén Laboratory
In the same journal
Plasma Physics and Controlled Fusion

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 28 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf