Y. Zayachuk I. Jepu M. Zlobinski C. Porosnicu N. Catarino E. Pajuste P. Petersson L. Dittrich J. P. Coad E. Grigore C. Postolache E. Alves G. Kizane M. Rubel A. Widdowson
This work was carried out to identify sources of errors, uncertainties and discrepancies in studies of fuel retention in wall components from the JET tokamak using methods based on thermal desorption. The parallel aim was to establish good practices in measurements and to unify procedures in data handling. A comprehensive program designed for deute…
PreprintA. Widdowson J.P. Coad Y. Zayachuk I. Jepu E. Alves N. Catarino V. Corregidor M. Mayer S. Krat J. Likonen C. Rowley M. Zlobinski D. Douai K. Heinola A. Baron-Wiechec L. Avotina JET Contributors
This contribution outlines a strategy for assessing tritium (T) inventory in plasma facing components (PFC) during JET T operations. It is based on retention as a fraction of fuel injected in-vessel, currently reported as 0.24% for 2011-2012 operating period, in conjunction with the planned T pulse schedule providing fueling of 4 g T injected per d…
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 favouri…
Preprint PublishedAnna Widdowson J.P. Coad E. Alves A. Baron-Wiechec N.P. Barradas N. Catarino V. Corregidor K. Heinola S. Krat M. Mayer K. Mizohata M. Sertoli JET contributors
Post mortem analysis shows that mid and high atomic number metallic impurities are present in deposits on JET plasma facing components with the highest amount of Ni and W, and therefore the largest sink, being found at the top of the inner divertor. Sources are defined as “continuous” or “specific”, in that “continuous” sources…
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…
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 Published