A.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 PublishedJ. Beal A. Widdowson K. Heinola A. Baron-Wiechec K. J. Gibson J. P. Coad E. Alves B. Lipschultz A. Kirschner G. F. Matthews S. Brezinsek JET-EFDA Contributors
Rotating collectors are used in JET to provide time-resolved measurements of erosion and redeposition of vessel materials. The silicon collecting disks rotate behind an aperture, driven by pulsing of the toroidal magnetic field, with the deposits analysed ex-situ by Nuclear Reaction Analysis. The angular dependence of deposition is mapped to discha…
Preprint PublishedA. J. Webster J. Morris T. N. Todd S. Brezinsek P. Coad J. Likonen M. Rubel JET EFDA Contributors
A unique sequence of 120 almost identical plasmas in the Joint European Torus (JET) recently provided two orders of magnitude more statistically equivalent data than ever previously available. The purpose was to study movement of eroded plasma-facing material from JET’s new Beryllium wall, but it has allowed the statistical detection of otherwise…
PublishedA.J. Webster R.O. Dendy F.A. Calderon S. C. Chapman E. Delabie D. Dodt R. Felton T. N. Todd F. Maviglia J. Morris V. Riccardo B. Alper S. Brezinsek P. Coad J. Likonen M. Rubel JET EFDA Contributors
For a two week period during the Joint European Torus (JET) 2012 experimental campaign, the same high confinement plasma was repeated 151 times. The dataset was analysed to produce a probability density function (pdf) for the waiting times between edge-localised plasma instabilities (“ELMs”). The result was entirely unexpected. Instead of a smo…
PublishedS. Grünhagen Romanelli S. Brezinsek B. Butler J.P. Coad A. Drenik C. Giroud S. Jachmich T. Keenan U. Kruezi M. Mozetic M. Oberkofler A. Parracho M. Romanelli R. Smith JET EFDA Contributors
Analytical results of a complete JET cryopump regeneration, including the nitrogen panel, follow- ing the first ITER-Like Wall campaign are presented along with the in-situ analyses of residual gas. H/D mixtures and impurities such as nitrogen and neon were injected during plasma operation in the vessel to study radiation cooling in the scrape-off-…
PublishedJ.P. Coad E. Alves N.P. Barradas A. Baron-Wiechec K. Heinola J. Likonen M. Mayer G.F. Matthews P. Petersson A. Widdowson JET-EFDA Contributors
This paper reports on the first post-mortem analyses of tiles removed from JET after the first campaigns with the ITER-like Wall (ILW) during 2011-2 [1]. Tiles from the divertor have been analysed by the Ion Beam Analysis (IBA) techniques Rutherford Backscattering Spectroscopy (RBS) and Nuclear Reaction Analysis (NRA) and by Secondary Ion Mass Spec…
PublishedA. Widdowson C.F. Ayres S. Booth J.P. Coad A. Hakola K. Heinola D. Ivanova S. Koivuranta J. Likonen M. Mayer M. Stamp JET-EFDA Contributors
A complete global balance for carbon in JET requires knowledge of the net erosion in the main chamber, net deposition in the divertor and the amount of dust and flakes collecting in the divertor region. This paper describes a number of measurements on aspects of this global picture. Profiler measurements and cross section microscopy on tiles that w…
PublishedN. P. Barradas J. Likonen E. Alves L. C. Alves P. Coad et al.
IBA techniques such as RBS, ERDA, NRA, or PIXE are highly complementary, and are often combined to maximize the extracted information. In particular, they have different sensitivities to various elements and probe different depth scales. The same is true for secondary ion mass spectrometry (SIMS), that can have much better detection limits for many…
PublishedA. Kreter H. G. Esser S. Brezinsek J. P. Coad A. Kirschner W. Fundamenski V. Philipps R. A. Pitts A. Widdowson
The impact of edge localized modes (ELMs) carrying energies of up to 450 kJ on carbon erosion in the JET inner divertor is assessed by means of time resolved measurements using an in situ quartz microbalance diagnostic. The inner target erosion is strongly nonlinearly dependent on the ELM energy: a single 400 kJ ELM produces the same carbon erosion…
Published