V.G. Kiptily M. Fitzgerald S.E. Sharapov M. Poradzinski Z. Stancar P. J. Bonofiglo R. Dumont Z. Ghani V. Goloborodko S. Menmuir1 D. Keeling M. Podestà H. Sun D.M. Taylor D. Douai J. Garcia C.F. Maggi J. Mailloux F. Rimini
The fusion-born alpha-particle heating in magnetically confined fusion machines is a high priority subject for study. The self-heating of thermonuclear fusion plasma by alpha-particles was observed in recent deuterium-tritium (D-T) experiments on the Joint European Torus (JET). This observation was possible by conducting so-called “after…
PreprintM. Fitzgerald R. Dumont D. Keeling J. Mailloux S. Sharapov M. Dreval A. Figueiredo R. Coelho J. Ferreira P. Rodrigues F. Nabais D. Borba Ž. Štancar G. Szepesi R.A. Tinguely N Fil P.G. Puglia H.J.C. Oliver V. Kiptily M. Baruzzo M. Lennholm P. Siren J. Garcia C.F. Maggi
A toroidal Alfven eigenmode (TAE) has been observed driven by alpha particles in the Joint European Torus (JET). The observation was made in dedicated deuterium-tritium experiments where radio-frequency (RF) heating was absent, in the so-called “afterglow” period when neutral beam heating was removed. Agreement with reduced and perturbative mod…
PreprintV.G.Kiptily Ye.O.Kazakov M.Nocente J.Ongena M.Dreval T.Craciunescu M.Fitzgerald L.Giacomelli V.Goloborodko D.Rigamonti A.V.Shevelev J.Garcia H.J.C.Oliver S.E.Sharapov Z.Stancar H. Weisen
Alfvén eigenmode (AE) instabilities driven by alpha-particles have been observed in D-3He fusion experiments on the Joint European Torus (JET) with the ITER-like wall (ILW). For the efficient generation of fusion alpha-particles from D-3He fusion reaction, the 3‑ion radio frequency (RF) scenario was used t…
Preprint PublishedR.A. Tinguely N. Fil P.G. Puglia S. Dowson M. Porkolab V. Guillemot M. Podesta M. Baruzzo A. Fasoli M. Fitzgerald Y. Kazakov M.F.F. Nave M. Nocente J. Ongena S.E. Sharapov Z. Stancar JET Contributors.
The interaction of Alfvén Eigenmodes (AEs) and energetic particles will determine the success of future tokamaks. In JET, eight in-vessel antennas were installed to actively probe stable AEs with frequencies ranging 25 – 250 kHz and toroidal mode numbers |n| < 20. During the 2019-2020 deuterium campaign, almost 7500 resonances and …
PreprintN. Fil S.E. Sharapov M. Fitzgerald G.J. Choi Z. Lin R.A. Tinguely H.J.C. Oliver K.G. McClements P.G. Puglia R.J. Dumont M. Porkolab JET Contributors
Recent JET Deuterium experiments with an advanced internal transport barrier (ITB) scenario have been performed to clearly observe destabilised toroidicity-induced Alfvén eigenmodes (TAEs) by fast ions; interestingly, these also exhibit unstable electromagnetic (EM) perturbations in the sub-TAE frequency range. We identify such EM perturbations to…
Preprint PublishedM. Fitzgerald S. E. Sharapov P. Siren E. Tholerus M. Dreval G. Szepesi P. Olivares T. Jonsson N. Fil J. Ferreira P. Rodrigues A. Figueiredo D. Borba R. Coelho F. Nabais J. Mailloux H.J.C. Oliver C. Di Troia F. Napoli Z. Stancar R. Dumont D. Keeling
In this work, we use reduced and perturbative models to examine the stability of TAEs during the ITB afterglow in JET experiments designed for the observation of alpha driven TAEs. We demonstrate that in JET-like conditions, it is sufficient to use an incompressible cold plasma model for the TAE to reproduce the experimental adiabatic features…
PreprintB. Geiger A. N. Karpushov S. Sharapov R. Akers A. Bock M. Dunne B. Duval M. Fontana L. Giannone J. Hobirk C. Hopf A.S. Jacobsen D. Keeling P. Lauber C. Marini P. ZS. Poloskei M. Salewski O. Sauter P. A. Schneider D. Testa A.J. Van Vuuren M. Willensdorfer TCV Team ASDEX Upgrade Team EUROfusion MST15 Team
The fast-ion transport has been investigated in low-collisionality discharges at ASDEX Upgrade and TCV using offaxis neutral beams. In both devices Alfven eigenmode activity was observed which does, however, not strongly affect the global fast-ion confinement. In contrast, charge exchange losses have been identified to have a strong effect. At TCV …
PreprintR.A. Tinguely P.G. Puglia N. Fil S. Dowson M. Porkolab A. Dvornova A. Fasoli M. Fitzgerald G.T.A. Huysmans M. Maslov S. Sharapov D. Testa JET Contributors
This paper presents a dedicated study of plasma-antenna (PA) coupling with the Alfvén Eigenmode Active Diagnostic (AEAD) in JET. Stable AEs and their resonant frequencies f, damping rates < 0, and toroidal mode numbers n are measured for various PA separations and limiter versus X-point magnetic cofigurations. Two stable AEs are observed to be …
Preprint PublishedV.G. Kiptily M. Fitzgerald Ye.O. Kazakov M. Nocente J. Ongena S.E. Sharapov M. Dreval Ž. Štancar T. Craciunescu J. Garcia L. Giacomelli V.Goloborodko J. Oliver H. Weisen
Dedicated experiments to generate high-energy D ions and D-3He fusion-born alpha particles have been performed at the Joint European Torus (JET) with the ITER-like wall (ILW). Deuterium ions from neutral beam injection (NBI) with acceleration voltage of 100 keV were accelerated to higher energies in the core of mixed D-3He…
Preprint PublishedJaemin Seo J. Kim J. Mailloux R.J. Dumont M. Fitzgerald S.E. Sharapov D.L. Keeling F. Koechl F.J. Casson C.Y. Lee T.S. Hahm Y.-S. Na JET contributors
Parametric dependencies of the linear stability of toroidal Alfven eigenmode (TAE) in the presence of neutral beam injection (NBI) are investigated to understand the beam drive and damping effect of TAEs in JET and KSTAR. It is found that the results depend on the drift orbit width of the beam-ions normalized to the characteristic mode widths. I…
Preprint Published