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…
PreprintThe JET contributors* (presented by J. Mailloux)
The JET 2019–2020 scientific and technological programme exploited the results of years of concerted scientific and engineering work, including the ITER-like wall (ILW: Be wall and W divertor) installed in 2010, improved diagnostic capabilities now fully available, a major neutral beam injection upgrade providing record power in 2019–2020, and …
Preprint PublishedM. 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…
PreprintA R Field D Fajardo F J Casson C Angioni C D Challis J Hobirk A Kappatou Hyun-Tae Kim E Lerche A Loarte J Mailloux JET Contributors
Screening of high-Z (W) impurities from the confined plasma by the temperature gradient at the hot edge pedestal of fusion-grade H-mode plasmas has been demonstrated for the first time in the JET-ILW tokamak. Through careful optimisation of the hybrid-scenario, deuterium plasmas with sufficient heating power (≳ 32MW), high enough ion temperature …
PreprintHJ. Sun SA. Silburn IS. Carvalho C Giroud G Fishpool GF. Matthews DB. King RB. Henriques DL. Keeling FG. Rimini L. Garzotti D. Frigione D. Van Eester D Kos M-L. Mayoral J. Mailloux C. Maggi A. Huber D. Douai PJ. Lomas L Morten M. Maslov K. Kirov P. Jacquet CG. Lowry M. Baruzzo C. Stuart J. Mitchell L. Horvath DC. McDonald JET Contributors
Unusually high power loads on the Beryllium limiter caused by Neutral Beam re-ionisation, and much cooler divertor target surfaces were observed during the recent JET tritium campaign. As both phenomena are driven by scrape-off layer (SOL) physics, the SOL features of 72 tritium H-mode discharges and their deuterium references have been studied. …
Preprint PublishedP. J. Bonofiglo V. Kiptily V. Goloborodko Z. Stancar M. Podesta F. E. Cecil C. D. Challis J. Hobirk A. Kappatou E. Lerche I. Carvalho J. Garcia J. Mailloux C. F. Maggi A. G. Meigs
Capacitive plasma pickup is a well-known and difficult problem for plasma-facing edge diagnostics. Ths problem must be addressed to ensure an accurate and robust interpretation of the real signal measurements versus noise. JET’s Faraday cup fast ion loss detector array is particularly prone to this issue and can be used as a …
Preprint PurchaseA R Field P Carvalho D Frigione L Garzotti Hyun-Tae Kim M Lenholm E Lerche J Mailloux F Rimini C M Roach M Sertoli G Szepeisi D van Eester.
Sustained operation of high-performance, ITER-baseline scenario plasmas at the high levels of input power (~< 40MA) required to achieve ~ 15 MW of D-T fusion power in JET-ILW requires careful optimisation of the fuelling to avoid an unacceptable disruption rate due to excessive radiation, primarily from W impurities, which are sputter…
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…
PreprintJaemin 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 PublishedC. Challis R. Dumont D. Frigione L. Garzotti J. Graves E Lerche J. Mailloux M. Mantsinen F. Rimini F. Casson A. Czarneka R. Felton J. Garcia C. Giroud E. Joffrin H.-T. Kim M. Lennholm P. Lomas C. Lowry L. Meneses I Nunes et al.
The JET exploitation plan foresees D-T operations in 2019-2020. With respect to the first D-T campaign in 1998, when JET was equipped with a carbon wall, the experiments will be conducted in presence of a beryllium-tungsten ITER-like wall and will benefit from an extended and improved set of diagnostics and higher available additional heating power…
Preprint Published