C. Giroud S. Brezinsek R. Pitts I.S. Carvalho A. Huber E. Kaveeva D. Keeling J. Mailloux S. Aleiferis B. Chapman S. Henderson L. Garzotti E. Lerche M. MArin M. Maslov M. Brix P. Carvalho I. Coffey J. Fontdecaba L. Horvath I. Jepu J. Karhunen E. Litherland-Smith A. Meigs R.B. Morales T. Pereira D. Refy Z. Stancar M. Sertoli S. Silburn G. Szepesi A. Thorman M. Tomes I. Veselova B. Viola S. Wiesen JET contributors,
JET has investigated one the key issues for the baseline scenario in ITER, the integration of a radiative divertor for heat load control with the use of neon and nitrogen as seed impurity. A characterization of the choice of the impurity seed on plasma confinement, neutrons, pedestal MHD stability, pedestal instabilities, core transport is given…
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 PublishedA 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 PublishedJ.C. Hillesheim E. Delabie E. Solano C.F. Maggi H. Meyer E. Belonohy I. Carvalho E. de la Luna A. Drenik M. Gelfusa C. Giroud J. Hobirk A.E. Hubbard A. Kappatou H.T. Kim A. Huber E. Lerche B. Lomanowski M. Mantsinen S. Menmuir I. Nunes E. Peluso F. Rimini P.A. Schneider M. Stamp G. Verdoolaege JET Contributors
Unraveling the conditions that permit access to H-mode continues to be an unresolved physics issue for tokamaks, and accurate extrapolations are important for planning ITER operations and DEMO design constraints. Experiments have been performed in JET, with the ITER-like W/Be wall, to increase the confidence of predictions for the L-H transition po…
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 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 PublishedA. R. Field P. Carvalho L. Garzotti E. Lerche C. Maggi F. Rimini C. Roach S. Saarelma M. Sertoli JET contributors
In high-performance, ITER baseline-scenario pulses (3MA/2.7T) in JET-ILW with high levels (~ 32 MW) of heating power, typically ~ 20-40% of the input power is radiated, predominantly by W impurities, which are sputtered from the divertor targets and reach the confined plasma. Sustained ELMy H-mode operation at such high heating power in JET-ILW req…
Preprint PublishedJ. S. Edwards I. S. Carvalho R. Felton C. Hogben D. Karkinsky P. J. Lomas P. A. McCullen F. G. Rimini A. V. Stephen
The JET Real-Time Protection Sequencer (RTPS) co-ordinates responses for magnetic and kinetic actuators to protect the ITER-Like Wall from possible melting events and other undesirable scenarios. It allows programmable stop responses per pulse, based on alarms raised by other systems. The architecture combines a modular run-time application deve…
Preprint PublishedSergei Gerasimov P. Abreu G Artaserse M. Baruzzo P. Buratti I.S. Carvalho I.H. Coffey E. de la Luna T.C. Hender R.B. Henriques R. Felton U. Kruezi P.J. Lomas P. McCullen M. Maslov E. Matveeva S. Moradi L. Piron F.G. Rimini W. Schippers G. Szepesi M. Tsalas L.E. Zakharov
The paper presents an analysis of disruptions occurring during JET-ILW plasma operations covering the period from the start of ILW (ITER-like wall) operation up to completion of JET operation in 2016. The total number of disruptions was 1951 including 466 with deliberately induced disruptions. The average disruption rate of unintended disruptions i…
Preprint Published