M.Yu. Lavrentiev A. Hollingsworth J. Hess S. Davies A. Wohlers B. Thomas H.Salter A. Baron-Wiechec I. Jepu Y. Zayachuk N. Peng
Molybdenum is used as plasma-facing material in tokamaks and as material for plasma optical diagnostic mirrors. Harsh conditions of neutron irradiation, exposure to hydrogen isotopes and helium, and high temperature result in degradation of molybdenum surface and ultimately limit the lifetime of fusion power plant. In the current paper, we inves…
PreprintY. 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…
Preprint PublishedC. 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…
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 PublishedLiga Avotina Anna Widdowson Ionut Jepu Aleksandra Baron-Wiechec Gunta Kizane JET Contributors
Understanding of fuel retention and release processes from plasma facing components (PFCs) of ITER like wall materials is important from fundamental and technological aspects [1]. Detailed information about fuel retention and release characteristics in plasma facing components from JET will allow…
Preprint PublishedA. 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…
PreprintI. 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 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 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 Published