S.Wiesen S. Brezinsek D. Harting T. Dittmar E. de la Luna D. Matveev K. Schmid JET contributors
There is experimental evidence that the pedestal dynamics in type-I ELMy H-mode discharges is significantly affected by a change in the recycling conditions at the tungsten plasma-facing components (W-PFCs) after an ELM event. The integrated code JINTRAC has been employed to assess the impact of recycling conditions during type-I ELMs in JET ITER-l…
PublishedJ. Beal A. Widdowson K. Heinola A. Baron-Wiechec K.J. Gibson J.P. Coad E. Alves B. Lipschultz A. Kirschner H.G. Esser G.F. Matthews S. Brezinsek JET Contributors
Rotating collectors and quartz microbalances (QMBs) are used in JET to provide time-dependent measurements of erosion and deposition. Rotation of collector discs behind apertures allows recording of the long term evolution of deposition. QMBs measure mass change via the frequency deviations of vibrating quartz crystals. These diagnostics are used t…
Preprint PublishedS. Wiesen M. Groth S. Brezinsek M. Wischmeier JET contributors
An overview is given on the recent progress on edge modelling activities for the JET ITER like wall using the computational tools like the SOLPS or EDGE2D-EIRENE code. The validation process of these codes on JET with its metallic plasma-facing components is an important step towards predictive studies for ITER and DEMO in relevant divertor operati…
Preprint PublishedD. Rendell S.R. Shaw P.J. Pool C. Oberlin-Harris JET EFDA Contributors
The JET flywheel generator converters have operated since 1983 and for over 85,000 pulses. Problems with this plant are discussed, including corrosion, unbalanced flow and arcing within the liquid resistors; starting difficulties on both machines; and failure of the plug-braking transformers at energisiation. In 2012/13 two sets of thrust bearing p…
Preprint PublishedJ. C. Flanagan M. Sertoli M. Bacharis G. F. Matthews P. C. de Vries A. Widdowson I. H. Coffey G. Arnoux B. Sieglin S. Brezinsek J. W. Coenen S. Marsen T. Craciunescu A. Murari D. Harting A. Cackett E. Hodille JET-EFDA Contributors
Recent studies dedicated to the characterisation of in-vessel dust in JET with the new ITER-like wall (ILW) show that dust levels are orders of magnitude lower compared with the latter stages of the carbon-wall (CW) period and are decreasing with operational time. Less than 1 g of dust was recovered in a recent inspection, compared with more than 2…
Preprint PublishedU. Kruezi S. Jachmich H.R. Koslowski M. Lehnen S. Brezinsek G. Matthews JET EFDA Contributors
Disruptions, the fast accidental losses of plasma current and stored energy in tokamaks, represent asignificant risk to the mechanical structure as well as the plasma facing components of reactor-scale fusion facilities like ITER. At JET, the tokamak experiment closest to ITER in terms of operating parameters and size, massive gas injection has bee…
Preprint PublishedE. Lerche M. Goniche P. Jacquet D. Van Eester V. Bobkov L. Colas A. Czarnecka S. Brezinsek M.Brix K. Crombe M. Graham M. Groth I. Monakhov T. Mathurin G. Matthews L. Meneses C. Noble V. Petrzilka F. Rimini A. Shaw JET-EFDA Contributors
Recent JET-ILW [1,2] experiments reiterated the importance of tuning the plasma fuelling in order to optimize ion cyclotron resonance frequency (ICRF) heating in high power H-mode discharges. By fuelling the plasma from gas injection modules (GIMs) located in the midplane and on the top of the machine instead of adopting the more standardly used di…
Preprint PublishedK.D. Lawson M. Groth P. Belo S. Brezinsek G. Corrigan A. Czarnecka E. Delabie P. Drewelow D. Harting I. KsiaSek C.F. Maggi C. Marchetto A.G. Meigs S. Menmuir M.F. Stamp S. Wiesen JET-EFDA Contributors
A discrepancy in the divertor radiated powers between EDGE2D-EIRENE simulations, both with and without drifts, and JET-ILW experiments employing a set of NBI-heated L-mode discharges with step-wise density variation is investigated. Results from a VUV/visible poloidally scanning spectrometer are used together with bolometric measurements to determi…
Preprint PublishedA.Baron-Wiechec A.Widdowson E.Alves C.F.Ayres N. P. Barradas S.Brezinsek J.P.Coad N.Catarino K.Heinola J.Likonen G.F.Matthews M.Mayer P. Petersson M.Rubel W. van Renterghem I. Uytdenhouwen JET-EFDA contributors
A set of Be and W tiles removed after the first ITER-like Wall campaigns (JET-ILW) from 2011-2012 has been analysed. The results indicate that the primary erosion site is in the main chamber (Be) as in previous carbon campaigns (JET-C). In particular the limiters tiles near the mid-plane are eroded probably during the limiter phases of discharges. …
Preprint PublishedK. Heinola A. Widdowson J. Likonen E. Alves A. Baron-Wiechec N. Barradas S. Brezinsek N. Catarino P. Coad S. Koivuranta G.F. Matthews M. Mayer P. Petersson JET-EFDA Contributors
Selected Ion Beam Analysis techniques applicable for detecting deuterium and heavier impurities have been used in the post-mortem analyses of tiles removed after the first JET ITER-Like Wall (JET-ILW) campaign. Over half of the retained fuel was measured in the divertor region. The highest figures for fuel retention were obtained from regions with …
Preprint Published