Observations of toroidicity-induced Alfven eigenmodes in a reversed field pinch plasma
2005 (English)In: Physics of Plasmas, ISSN 1070-664X, Vol. 12, no 4Article in journal (Refereed) Published
High frequency peaks in the spectra of magnetic field signals have been detected at the edge of Extrap-T2R [P. R. Brunsell, H. Bergshker, M. Cecconello, J. R. Drake, R. M. Gravestijn, A. Hedqvist, and J-A. Malmberg, Plasma Phys. Controlled Fusion, 43, 1457 (2001)]. The measured fluctuation is found to be mainly polarized along the toroidal direction, with high toroidal periodicity n and Alfvenic scaling (f proportional to B / root m(i)n(i)). Calculations for, a reversed field pinch plasma predict the existence of an edge resonant, high frequency, high-n number toroidicity-induced Alfven eigenmode with the,observed frequency scaling. In addition, gas puffing experiments show that edge density fluctuations are responsible for the rapid. changes of mode frequency. Finally a coupling with the electron drift turbulence is proposed as drive mechanism for the eigenmode.
Place, publisher, year, edition, pages
2005. Vol. 12, no 4
tokamaks, mode, excitation, turbulence, particles, transport, rotation, spectra
IdentifiersURN: urn:nbn:se:kth:diva-14723DOI: 10.1063/1.1861896ISI: 000228865900030ScopusID: 2-s2.0-20844463454OAI: oai:DiVA.org:kth-14723DiVA: diva2:332764
QC 201005252010-08-052010-08-05Bibliographically approved