HJ. 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 PublishedG. 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…
PreprintS.N. Gerasimov P. Abreu L.R. Baylor A. Boboc I.S. Carvalho I.H. Coffey D. Craven V. Huber S. Jachmich E. Joffrin U. Kruezi M. Lehnen P.J. Lomas A. Manzanares M. Maslov E. Matveeva G. Pautasso A. Peacock S. Silburn C. Stuart H. Sun D. Shiraki R. Sweeney J. Wilson L.E. Zakharov
The disruption mitigation system at ITER will include four shattered pellet injectors (SPI), which will be dedicated to the mitigation of electro-magnetic loads (EML), thermal loads and the avoidance and suppression of runaway electrons. Recently the JETILW was equipped with an SPI with a wide capability. Specifically: pellet diameter d = [4.57, 8.…
PreprintC.I. Stuart G. Artaserse P. Card I.S. Carvalho R. Felton S.N. Gerasimov A. Goodyear R.B. Henriques D. Karkinsky P.J. Lomas P. McCullen F. Rimini A.V. Stephen D.F. Valcárcel J. Waterhouse M. Wheatley
Plasma Event TRiggering for Alarms (PETRA) is a flexible new system at JET for detecting plasma events to trigger exception handling responses. It provides a platform for all existing and new techniques which involve processing JET real-time data to identify when to change the trajectory of a plasma shot, and reduces the technical cost and risk in …
Preprint PublishedV. K. Zotta L. Garzotti F. J. Casson D. Frigione F. Koechl E. Lerche P. Lomas F. Rimini M. Sertoli D. Van Eester R. Gatto C. Mazzotta G. Pucella
The fusion performance of ELMy H-mode DT plasmas with q95 = 3 and \\beta_N = 1.8 (also referred to as medium-\\beta_N baseline scenario in the rest of this paper) are predicted with the JINTRAC suite of codes and the QuaLiKiZ transport model. The predictions are based on the analysis of DT plasmas from the first DT campaign on JET in 1997 (DTE1…
PreprintG. Pucella E. Giovannozzi P. Buratti E. Alessi F. Auriemma D. Brunetti P. J. Lomas S. Nowak C. Sozzi JET Contributors
In this work the mechanisms that can lead to disruptive MHD instabilities in the termination phase of plasma pulses on JET are investigated. It is shown that the broadening or the shrinking of the current density profile, as a consequence of a core hollowing or a edge cooling of the electron temperature profile, can lead to the destabilization o…
Preprint PublishedK. 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 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 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 PublishedS.N. Gerasimov G Artaserse P. Buratti I.S. Carvalho E. de la Luna T.C. Hender R.B. Henriques P.J. Lomas E. Matveeva S. Moradi L. Piron F.G. Rimini G. Szepesi L.E. Zakharov JET Contributors
An n = 1 locked, or slowly rotating, mode has been observed in most pulses prior to JET disruptions. However, a small fraction of non-disruptive pulses has a locked mode which eventually vanishes without disruption. Hence, on JET the locked mode amplitude is routinely used as an indicator of unhealthy plasma. There are two threshold levels…
Preprint Published