Determination of the minimum value of the safety factor from geodesic Alfven eigenmodes in Joint European Torus

Journal Article · Mon Nov 15 04:00:00 EST 2010 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3494212· OSTI ID:21531934

Elfimov, A G ^[1]; Galvao, R M. O. ^[1]; Sharapov, S E ^[2]

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1. Institute of Physics, University of Sao Paulo, 05508-090 Sao Paulo (Brazil)
2. Euratom/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom)

An analysis of the experimental conditions under which low-frequency (70-150 kHz) Alfven eigenmodes (AE) are excited during the monster sawtooth in Joint European Torus [F. Romanelli et al., Proceedings of the 22nd IAEA Fusion Energy Conference, Geneva, Switzerland, 2008] is presented for the specific case of a discharge with ion cyclotron heating (5 MW). Using a simplified AE model for modes excited at the Alfven wave continuum maximum with geodesic corrections taken into account, the temporal evolution of the value of the safety factor q{sub 0} at the magnetic axis is determined. We describe a new scheme to determine the time variation of q{sub 0} that works under conditions in which other standard diagnostics, such as the motional Stark effect do not give reliable results such as during a monster sawtooth.

• OSTI ID: 21531934
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 11 Vol. 17; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ALFVEN WAVES
CLOSED PLASMA DEVICES
FLUID MECHANICS
HEATING
HIGH-FREQUENCY HEATING
HYDRODYNAMICS
HYDROMAGNETIC WAVES
ICR HEATING
INSTABILITY
JET TOKAMAK
MAGNETOHYDRODYNAMICS
MECHANICS
OSCILLATIONS
PLASMA
PLASMA HEATING
PLASMA INSTABILITY
REACTOR SAFETY
SAFETY
SAWTOOTH OSCILLATIONS
STARK EFFECT
THERMONUCLEAR DEVICES
THERMONUCLEAR REACTORS
TOKAMAK DEVICES