R.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 abs(n)< 20. During the 2019-2020 deuterium campaign, almost 7500 resonances and …
Preprint PublishedN. 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…
Preprint PublishedD. Moulton A. Fil O. Myatra B. Lipschultz B. Dudson
The paper reviews recent SOLPS modelling of long-legged divertors carried out by UKAEA and the University of York. The required upstream density required for detachment is predicted to scale inversely with the total flux expansion of the divertor, but experimentally this was not found to be the case on TCV. Interpretative SOLPS-ITER modelling sugge…
PreprintK. Verhaegh B. Lipschultz C. Bowman B.P. Duval U. Fantz A. Fil D. Moulton O. Myatra D. Wünderlich F. Federici D.S. Gahle J.R. Harrison A. Perek M. Wensing
Detachment, an important mechanism for reducing target heat deposition, is achieved through reductions in power, particle and momentum; which are induced through plasma-atom and plasma-molecule interactions. Experimental research in how those reactions precisely contribute to detachment is limited. Both plasma-atom as well as plasma-molecule intera…
Preprint PublishedR.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 PublishedR.A. Tinguely P.G. Puglia N. Fil S. Dowson M. Porkolab A. Fasoli D. Testa JET Contributors
This paper presents results of extensive analysis of mode excitation observed during the operation of the Alfvén Eigenmode Active Diagnostic (AEAD) in the JET tokamak during the 2019-2020 deuterium campaign. Six of eight toroidally-spaced antennas, each with independent power and phasing, were successful in actively exciting stable MHD modes in…
Preprint PublishedS. Dowson S. Dorling H. K. Sheikh T. Blackman G. Jones A. Goodyear P. Puglia P. Blanchard A. Fasoli D. Testa N. Fil V. Aslanyan M. Porkolab W. Pires De Sa R. Galvao L. Ruchko J. Figueiredo C. Perez Von Thun JET Contributors
The Alfvén Eigenmode Active Diagnostic system (AEAD) has undergone a major upgrade and redesign to provide a state of the art excitation and real-time detection system for JET. The new system consists of individual 4kW amplifiers for each of the six antennas, allowing for increased current, separate excitation and real time control of relative …
Preprint PublishedS.F. Smith S.J.P. Pamela A. Fil M. Hoelzl G.T.A. Huijsmans A. Kirk D. Moulton O. Myatra A.J. Thornton H.R. Wilson
ELM simulations for the MAST-U Super-X tokamak have been obtained, using the JOREK code. The JOREK visco-resistive MHD model has been used to obtain comparisons of divertor configurations. The simulations show a factor 10 decrease in the peak heat flux to the outer target of the Super-X in comparison to a conventional divertor configuration. A roll…
Preprint PublishedN. 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 Published