Explanation of the JET n=0 chirping mode
2006 (English)In: Nuclear Fusion, ISSN 0029-5515, E-ISSN 1741-4326, Vol. 46, no 10, S888-S897 p.Article in journal (Refereed) Published
Persistent rapid up and down frequency chirping modes with a toroidal mode number of zero (n = 0) are observed in the JET tokamak when energetic ions, in the range of several hundred keV, are created by high field side ion cyclotron resonance frequency heating. Fokker-Planck calculations demonstrate that the heating method enables the formation of an energetically inverted ion distribution which supplies the free energy for the ions to excite a mode related to the geodesic acoustic mode. The large frequency shifts of this mode are attributed to the formation of phase space structures whose frequencies, which are locked to an ion orbit bounce resonance frequency, are forced to continually shift so that energetic particle energy can be released to counterbalance the energy dissipation present in the background plasma.
Place, publisher, year, edition, pages
2006. Vol. 46, no 10, S888-S897 p.
zonal flows, alfven eigenmodes, tokamak plasmas, dynamics, waves
IdentifiersURN: urn:nbn:se:kth:diva-16125DOI: 10.1088/0029-5515/46/10/S04ISI: 000242004100004ScopusID: 2-s2.0-33749064350OAI: oai:DiVA.org:kth-16125DiVA: diva2:334167
QC 20100525 QC 20110927. Conference: 9th IAEA Technical Meeting on Energetic Particles in Magnetic Confinements Systems. Takayama, JAPAN. NOV 09-11, 2005 2010-08-052010-08-052011-09-28Bibliographically approved