Fast-Ion Losses due to High-Frequency MHD Perturbations in the ASDEX Upgrade Tokamak

Journal Article · Fri Feb 08 00:00:00 EST 2008 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.100.055005· OSTI ID:21024722

Garcia-Munoz, M; Fahrbach, H -U; Guenter, S; Igochine, V; Maraschek, M; Zohm, H ^[1]; Mantsinen, M J ^[1]; Martin, P; Piovesan, P ^[2]; Sassenberg, K ^[1]

---

1. Max-Planck-Institut fuer Plasmaphysik, EURATOM Association Boltzmannstrasse 2, D-85748 Garching (Germany)
2. Consorzio RFX, Associazione EURATOM-ENEA per la fusione, Padova (Italy)

Time-resolved energy and pitch angle measurements of fast-ion losses correlated in frequency and phase with high-frequency magnetohydrodynamic perturbations have been obtained for the first time in a magnetic fusion device and are presented here. A detailed analysis of fast-ion losses due to toroidal Alfven eigenmodes has revealed the existence of a new core-localized magnetohydrodynamic perturbation, the sierpes mode. The sierpes mode is a non-Alfvenic instability which dominates the losses of fast ions in ion cyclotron resonance heated discharges, and it is named for its footprint in the spectrograms ('sierpes' means 'snake' in Spanish). The sierpes mode has been reconstructed by means of highly resolved multichord soft-x-ray measurements.

• OSTI ID: 21024722
• Journal Information: Physical Review Letters, Vol. 100, Issue 5; Other Information: DOI: 10.1103/PhysRevLett.100.055005; (c) 2008 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ALFVEN WAVES
ASDEX TOKAMAK
CYCLOTRON RESONANCE
MAGNETOHYDRODYNAMICS
PERTURBATION THEORY
PLASMA INSTABILITY
SOFT X RADIATION
TIME RESOLUTION