G. Pucella E. Alessi P. Buratti M. V. Falessi E. Giovannozzi F. Zonca M. Baruzzo C. D. Challis R. Dumont D. Frigione L. Garzotti J. Hobirk A. Kappatou D. L. Keeling D. King E. Lerche P. J. Lomas M. Maslov I. Nunes F. Rimini P. Siren C. Sozzi M. F. Stamp Z. Stancar D. Van Eester M. Zerbini
The experimental observation of multiple oscillations likely associated with beta-induced Alfven eigenmodes with toroidal mode number n = 1, 2 during strong tearing activity in JET plasmas is reported in this work. It is found the frequencies of these oscillations range from 5 kHz to 20 kHz, being consistent with the low-frequency beta-induc…
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 PublishedS. Saarelma L. Frassinetti P. Bilkova C.D. Challis A. Chankin R. Fridström L. Garzotti L. Horvath C.F. Maggi JET Contributors
The self-consistent core-pedestal prediction model of a combination of EPED1 type pedestal prediction and a simple stiff core transport model is able to predict type I ELMy pedestals of a large database JET-ILW (ITER-like wall) at the similar accuracy as is obtained when the experimental global plasma b is used as input. The neutral penetration …
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 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 PublishedC. Giroud N. Aiba F. Militello C. Challis A. Chankin B. Lomanowski D. Hatch J. Harrison D. Frigione D. Moulton S. Pamela F. Parra J. Parisi I. Putzai D. Refy S. Saarelma C. Stavrou B. Tal E. Belonohy S. Brezinsek S. Buller C. Bowman E. Delabie A. Field J. Fontdecaba A. Huber A. Meigs S. Menmuir J. Simpson JET Contributors
Preprint Published
D. Iglesias W. Arter I. Balboa P. Bunting C. Challis J.W. Coenen Y. Corre S. Esquembri S. Jachmich K. Krieger G.F. Matthews R.A. Pittsh V. Riccardo M.L. Richiusa M. Porton F. Rimini S. Silburn V.K. Thompson R. Otin D. Valcarcel L. Vitton-Mea Z. Vizvary J. Williams JET contributors
The JET outboard divertor targets are the in-vessel components which receive the largest heat flux density. Surface delamination, radial cracks, and tie rod failures have been observed in the outboard tungsten-coated CFC tiles, while bulk tungsten special lamellas were intentionally melted in dedicated experiments. These different types of damag…
PreprintB. Patel C. Challis D. Dickinson L. Garzotti F. Koechl C. Roach G. Staebler H. Wilson
Spherical Tokamaks (STs) could provide a route towards a compact fusion reactor due to advantageous properties such as high plasma beta. A GW-scale ST plasma is explored where Q=10 and R=2.5m. In this design 110 MW of NBI is needed to provide 9 MA of noninductive current, where the remaining 12 MA is pressure driven. To penetrate into the core a 1 …
Preprint PublishedC.D. Challis S. Brezinsek I. Coffey M. Fontana N. Hawkes D. Keeling D. King G. Pucella E. Viezzer JET Contributors
The initial current ramp phase of JET hybrid plasmas is used to optimise the target q-profile for main heating to allow access to high beta and avoid MHD instabilities. Mixed protium-deuterium experiments, carried out at JET since the installation of the beryllium-tungsten wall, have shown that the q-profile evolution during this Ohmic phase varies…
Preprint PublishedL. Piron T. C. Hender E. Joffrin F. Auriemma P. Buratti R. Paccagnella P. Zanca C. Challis S. Gerasimov R. B. Henriques L. Marrelli P. Lomas F. Rimini D. Terranova
The presence of Error Fields (EFs) in magnetic fusion devices can affect energy confinement and plasma stability by braking plasma rotation, by inducing fast particle losses and being amplified when exploring high-b regimes. The resulting EF Locked Modes (LMs) can be stabilized by NBI injection through the rotation shielding mechanism. However, …
Preprint Published