N. Fil M. Porkolab P. Puglia V. Aslanyan S. Dowson M. Fitzgerald S. E. Sharapov H. K. Sheikh Z. Lin J. Bao P. Blanchard A. Fasoli D. Testa J. Mailloux M. Tsalas M. Maslov A. Whitehead R. Scannell S. Gerasimov S. Dorling T. Blackman G. Jones A. Goodyear K. K. Kirov R. Dumont M. Podesta JET Contributors
The resonant detection and measurement of the damping rates of Alfvén Eigenmodes (AEs) is of critical importance to the design of experiments and development of models of AE stability [1]. With the Alfvén Eigenmodes Active Diagnostic (AEAD) on JET, weakly-damped Toroidal AEs (TAEs) have been probed. Theoretical modeling using the Gyrokinetic Toro…
Preprint PublishedAllah Rakha M.J. Mantsinen A.V. Melnikov S.E. Sharapov D.A. Spong A. Lopez-Fraguas F. Castejon
Alfven frequency sweeping modes in stellarator plasmas with normal and reversed shear rotational transform are modelled using a reduced MHD model. We focus on a TJ-II dynamic discharge in which a sequence of frequency sweeping modes with a frequency sweeping range from 20 kHz to 140 kHz (Melnikov A.V. et al 2014 Nucl. Fusion 54 123002) have been ob…
Preprint PublishedA. Dvornova G.T.A. Huijsmans S. Sharapov F.J. Artola P. Puglia M. Hoelzl S. Pamela A. Fasoli D. Testa
Toroidal Alfven Eigenmode (TAE) excitation can be caused by fusion-born or Ion Cyclotron Resonance and neutral beam heating fast particles through wave-particle resonance. TAEs may affect fast particle confinement, reduce heating and current drive efficiency, cause damage to the first wall, and decrease overall plasma performance. Excitation of TA…
Preprint PublishedH. J. C. Oliver S. E. Sharapov B. N. Breizman A. K. Fontanilla D. A. Spong D. Terranova JET Contributors
Alfven eigenmodes driven by energetic particles are routinely observed in tokamak plasmas. These modes consist of poloidal harmonics of shear Alfven waves coupled by inhomogeneity in the magnetic field. Further coupling is introduced by 3D inhomogeneities in the ion density during the assimilation of injected pellets. This additional coupling modi…
Preprint PublishedLuca Garzotti C. Challis R. Dumont D. Frigione J. Graves E Lerche J. Mailloux M. Mantsinen F. Rimini F. Casson A. Czarnecka J. Eriksson R. Felton L. Frassinetti D. Gallart J. Garcia C. Giroud E. Joffrin H.-T. Kim N. Krawczyk M. Lennholm P. Lomas C. Lowry L. Meneses I. Nunes C. M. Roach M. Romanelli S. Sharapov S. Silburn A. Sips E. Stefanikova M. Tsalas D. Valcarcel M. Valovic JET contributors
The JET exploitation plan foresees D-T operations in 2020 (DTE2). With respect to the first D-T campaign in 1997 (DTE1), when JET was equipped with a carbon wall, the experiments will be conducted in presence of a beryllium-tungsten ITER-like wall (ILW) and will benefit from an extended and improved set of diagnostics and higher additional heating …
Preprint PublishedYu.V. Yakovenko V.V. Lutsenko B.S. Lepiavko V.Ya. Goloborodko Ya.I. Kolesnichenko A.I. Tishchenko V. Kiptily S. Sharapov L. Giacomelli T. Craciunescu H. Weisen JET Contributors
Results of simulations of the sawtooth-induced redistribution of fast ions in JET and ITER with the code OFSEF are presented. The dependence of the redistribution on the particle parameters (energy and pitch angle) is studied. The redistribution of the trapped and marginally passing particles is found to exhibit barrier-like behaviour at the separa…
Preprint PublishedJ.Galdon-Quiroga M.Garcia-Munoz S.Sharapov L.Sanchis-Sanchez L.Chen M.Dunne J.Gonzalez-Martin M.Hoelz A.S.Jacobsen K.G.McClements M.Nocente F.Orain J.F.Rivero-Rodriguez D.A.Ryan M.Salewski P.Schneider A.Snicker W.Suttrop Y.Todo M.A.Van Zeeland E.Viezzer M.Willensdorfer D.Zarzoso F.Zonca The ASDEX Upgrade Team MST1 Team
An edge resonant transport layer has been found to explain many aspects of fast-ion confinement under symmetry breaking 3D edge perturbations, such as edge localized modes (ELMs) and externally applied magnetic perturbations (MPs). Experimental measurements in the ASDEX Upgrade (AUG) tokamak show that fast-ion losses in the presence of symmetry bre…
Preprint PublishedM. Fitzgerald J. Buchanan R.J. Akers B.N. Breizman S.E. Sharapov
HALO (HAgis LOcust) solves the initial value Vlasov-Maxwell problem perturbatively for application to certain nonlinear wave-particle problems in tokamak plasmas. It uses the same basic approach as the HAGIS code (Pinches et al., 1998) for wave evolution but is built on the LOCUST-GPU full-orbit code (Akers et al., 2012) for the solution of the Ham…
Preprint PublishedA.V. Melnikov E. Ascasibar A. Cappa F. Castejon L.G. Eliseev C. Hidalgo P.O. Khabanov N.K. Kharchev A.S. Kozachek L.I. Krupnik M. Liniers S.E.Lysenko J.L. dePablos V.N. Zenin S.E. Sharapov M.V. Ufimtsev and TJ-II team
Alfven Eigenmodes were studied in low magnetic shear flexible heliac TJ-II (B0=0.95 T, =1.5 m, =0.22 m) NBI heated plasmas (PNBI <1.1 MW, ENBI=32 keV) by Heavy Ion Beam Probe (HIBP) [1, 2, 3]. The L-mode hydrogen plasma was investigated at various magnetic configurations with rotational transform t(a)/2
Preprint PublishedV. Aslanyan S. Taimourzadeh L. Shi Z. Lin G. Dong P. Puglia M. Porkolab R. Dumont S. E. Sharapov J. Mailloux M. Tsalas M. Maslov A. Whitehead R. Scannell S. Gerasimov S. Dorling S. Dowson H. K. Sheikh T. Blackman G. Jones A. Goodyear K. K. Kirov P. Blanchard A. Fasoli D. Testa JET Contributors
The Gyrokinetic Toroidal Code (GTC) has been used to study Toroidal Alfvén Eigenmodes (TAEs) in high-performance plasmas. Experiments performed at the Joint European Torus, where TAEs were driven by energetic particles arising from Neutral Beams, ion cyclotron resonant heating and resonantly excited by dedicated external antennas, have been simula…
Preprint Published