A. Hollingsworth M.-F. Barthe Z. Hu P. Desgardin M.Yu. Lavrentiev S.L. Dudarev P. Derlet D. Mason J. Hess S. Davies B. Thomas H. Salter E.F.J. Shelton K. Heinola K. Mizohata A. De Backer A. Baron-Wiechec I. Jepu E. Zayachuk A. Widdowson E. Meslin A. Morellec
Self-ion bombardment of pure tungsten with ion energies of 2 MeV is used to mimic the defects created by neutrons in a fusion reactor. Electron microscopy is used to characterize the microstructure of samples. Thermal Desorption Spectrometry (TDS) is performed on deuterium implanted samples in order to estimate deuterium inventory as function of…
Preprint PublishedI. Jepu G.F. Matthews A. Widdowson M. Rubel E. Fortuna-Zaleśna J. Zdunek P. Petersson V. Thompson P. Dinca C. Porosnicu P. Coad K. Heinola N. Catarino O.G. Pompilian C. P. Lungu JET Contributors
Data on erosion and melting of beryllium upper limiter tiles, so-called dump plates (DP), are presented for all three campaigns in the JET tokamak with the ITER-like wall. High-resolution images of the upper wall of JET show clear signs of flash melting on the ridge of the roof-shaped tiles. The melt layers move in the poloidal direction from the i…
PublishedA. Widdowson E. Alves L. Avotina A. Baron Wiechec N. Catarino J P. Coad V. Corregidor K. Heinola I. Jepu JET Contributors
JET has now completed three operating periods, ILW1, ILW2 and ILW3, giving an opportunity to make comparisons between tiles exposed for single operating periods and also comparisons of tiles exposed for all three periods, ILW1-3 (2011-2016). In this contribution, a comprehensive overview of fuel retention and material erosion/deposition patterns…
Preprint PublishedJ. P. Coad M. Rubel J. Likonen N. Bekris S. Brezinsek G. F. Matthews M. Mayer A. M. Widdowson JET contributors
The first divertor was installed in the JET machine between 1992 and 1994 and was operated with carbon tiles and then beryllium tiles in 1994–5. Post-mortem studies after these first experiments demonstrated that most of the impurities deposited in the divertor originate in the main chamber, and that asymmetric deposition patterns generally favou…
PublishedA. Hollingsworth M. Yu. Lavrentiev R. Watkins A. Davies S. Davies R. Smith D. R. Mason A. Baron-Wiechec Z. Kollo J. Hess I. Jepu K. Heinola J. Likonen K. Mizohata E. Meslin M.-F. Barthe A. Widdowson I. S. Grech K. Abraham A. McShee Y. Martynova M. Freisinger A. De Backer
A new facility to study the interaction of hydrogen isotopes with nuclear fusion relevant first wall materials, its retention and release, has been produced. The new facility allows implanting a range of gases into samples, including tritium. Accurate study of isotope effects, such as the isotopic exchange in damaged microstructure, has previously …
Preprint 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 PublishedA. Widdowson A. Baron-Wiechec P. Batistoni E. Belonohy J.P. Coad P. Dinca D. Flammini F. Fox K Heinola I. Jepu J. Likonen S. Lilley C.P. Lungu G.F. Matthews J. Naish O. Pompilian C. Porosnicu M. Rubel R. Villari JET Contributors
JET components are removed periodically for surface analysis to assess material migration and fuel retention. This paper describes issues related to handling JET components and procedures for preparing samples for analysis; in particular a newly developed procedure for cutting beryllium tiles is presented. Consideration is also given to the hazards…
Preprint PublishedA. Baron-Wiechec E. Fortuna-Zalesna J. Grzonka M. Rubel A. Widdowson C. Ayres J.P. Coad C. Hardie K. Heinola G.F. Matthews JET Contributors
Results of the first dust survey in JET with the ITER - Like Wall (JET - ILW) are presented. The sampling was performed using adhesive stickers from the divertor tiles where the greatest material deposition was detected after the first JET - ILW campaign in 2011 - 2012. The emphasis was especially on metal particles (Be and W) with the aim to deter…
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 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 Published