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…
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.A. Schneider C. Angioni L. Frassinetti L. Horvath M. Maslov F. Auriemma M. Cavedon C.D. Challis E. Delabie M.G. Dunne J.M. Fontdecaba Climent J. Hobirk A. Kappatou D.L. Keeling B. Kurzan M. Lennholm B. Lomanovski C.F. Maggi R.M. McDermott T. Pütterich A. Thorman M. Willensdorfer
Experiments in ASDEX Upgrade (AUG) and JET with the ITER-like wall (JET-ILW) are performed to separate the pedestal and core contributions to confinement in H-modes with different main ion masses. A strong isotope mass dependence in the pedestal is found which is enhanced at high gas puffing. This is because the ELM type changes when going fro…
Preprint PublishedP. Ollus R. Akers H. El-Haroun D. Keeling T. Kurki-Suonio R. Sharma A. Snicker J. Varje MAST-U Team MST1 Team
The ASCOT orbit-following code has been equipped with a model for simulating charge exchange (CX) of fast ions with background atoms in magnetically confined fusion plasmas. The model was successfully verified by comparing simulated reaction mean free paths to analytical values across a range of fusion-relevant parameters. ASCOT was used to simulat…
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 …
PreprintK. K. Kirov E. Belonohy C. D. Challis J. Eriksson D. Frigione L. Garzotti L. Giacomelli J. Hobirk A. Kappatou D. Keeling D. King E. Lerche P. J. Lomas M. Nocente C. Reux F. G. Rimini A. C. C. Sips D. Van Eester JET Contributors
Achieving high neutron yields in today’s fusion research relies on high power auxiliary heating in order to attain required core temperatures. This is usually achieved by means of high Neutral Beam (NB) and Radio Frequency (RF) power. Application of NB power is accompanied by production of fast beam ions and associated Beam-Target (BT) reactio…
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 PublishedD. B. King E. Viezzer I. Balboa M. Baruzzo E. Belonohy J. Buchanan I.S. Carvalho K. Cave-Ayland I. Coffey C.D. Challis E.G. Delabie L. Garzotti S. Hall J.Hillesheim L. Horvath E. Joffrin D. Keeling K. Kirov C.F. Maggi M. Maslov S. Saarelma S. Silburn E.R. Solano M. Stamp D. Valcarcel H.Weisen
A study of mixed hydrogen-deuterium H-mode plasmas has been carried out in JET-ILW to strengthen the physics basis for extrapolations to JET D-T operation and to support the development of strategies for isotope ratio control in future experiments. Variations of input power, gas fuelling and isotopic mixture were performed in H-mode plasmas of the…
Preprint Published