E. Lerche D. Van Eester Ph. Jacquet M.-L. Mayoral V. Bobkov L. Colas A. Czarnecka M. Graham G. Matthews I. Monakhov R. Neu T. Puetterich F. Rimini P. De Vries JET-EFDA Contributors
After the change over from the C-wall to the ITER-like Be/W wall (ILW) in JET, the radiation losses during ICRF heating have increased and are now substantially larger than those observed with NBI at the same power levels, in spite of the similar global plasma energies reached with the two heating systems. A comparison of the NBI and ICRF performan…
PublishedM.-L. Mayoral T. Pütterich P. Jacquet E. Lerche D. Van-Eester V. Bobkov C. Bourdelle L. Colas A. Czarnecka J. Mlynar R. Neu JET-EFDA Contributors
During the initial operation of the JET ITER-like wall, particular attention was given to the characterization of the Ion Cyclotron Resonance Frequency (ICRF) heating in this new metallic environment. In this contribution we compare L-modes plasmas heated by ICRF or by Neutral Beam Injection (NBI). ICRF heating as expected led to a much higher cent…
PublishedA. Czarnecka V. Bobkov I. H. Coffey L. Colas P. Jacquet K. D. Lawson E. Lerche C. Maggi M.-L. Mayoral T. Pütterich D. Van Eester JET-EFDA Contributors
Magnetically confined plasmas, such as those produced in the tokamak JET, contain measurable amounts of impurity ions produced during plasma-wall interactions (PWI) from the plasma-facing components and recessed wall areas. The impurities, including high- and mid-Z elements such as tungsten (W) from first wall tiles and nickel (Ni) from Inconel str…
PublishedD. Van Eester E. Lerche P. Jacquet V. Bobkov A. Czarnecka J. W. Coenen L. Colas K. Crombé M. Graham S. Jachmich E. Joffrin C. C. Klepper V. Kiptily M. Lehnen C. Maggi F. Marcotte G. Matthews M.-L. Mayoral K. McCormick I. Monakhov M. F. F. Nave, R. Neu, C. Noble, J. Ongena, T. Pütterich, F. Rimini, E. R. Solano, G. van Rooij, and JET-EFDA contributors
The most recent JET campaign has focused on characterizing operation with the "ITER-like" wall. One of the questions that needed to be answered is whether the auxiliary heating methods do not lead to unacceptably high levels of impurity influx, preventing fusion-relevant operation. In view of its high single pass absorption, hydrogen minority funda…
PublishedT. Franke E. Barbato A. Cardinali S. Ceccuzzi R. Cesario D. V. Eester E. Lerche M.-L. Mayoral F. Mirizzi M. Nightingale J.-M. Noterdaeme E. Poli A. A. Tuccillo R. Wenninger H. Zohm
The aim of driving a sufficient amount of plasma current with an appropriate radial current density profile is considered as one of the key challenges for a tokamak fusion power plant in steady state operation. Furthermore, efficient heating to enable transition to regime of enhanced confinement and to achieve breakeven plasma temperatures as well …
PublishedC. Giroud G.P. Maddison S. Jachmich F. Rimini M. Beurskens I. Balboa S. Brezinsek R. Coelho J.W.Coenen Et Al
This paper reports the impact on confinement and power load of the high-shape 2.5MA ELMy H-mode scenario at JET of a change from an all carbon plasma facing components to an all metal wall. In preparation to this change, systematic studies of power load reduction and impact on confinement as a result of fuelling in combination with nitrogen seeding…
PublishedM.R. Gilbert S.L. Dudarev D.Nguyen-Manh L.W. Packer J-Ch. Sublet
In a fusion reactor materials will be subjected to significant fluxes of high-energy neutrons. As well as causing radiation damage, the neutrons also initiate nuclear reactions leading to changes in the chemical composition of materials (transmutation). Many of these reactions produce gases, particularly helium, which cause additional swelling and …
PublishedT N Todd
Now that ITER is under construction, interest is increasing in the specification and design of the successor machine, a Demonstration Power Plant (DEMO), which in Europe is coordinated by the EFDA Power Plant Physics and Technology programme. This paper summarises the work carried out for EFDA in 2011-2012 on design issues pertinent to a pulsed ver…
PublishedI.Lupelli A.Murari P.Gaudio M.Gelfusa D.Mazon J.Vega
The development of computationally efficient model selection strategies represents an important problem facing the analysis of Nuclear Fusion experimental data, in particular in the field of scaling laws for the extrapolation to future machines, and image processing. In this paper, a new model selection indicator, named Model Falsification Criterio…
PublishedV Riccardo P Lomas G F Matthews I Nunes V Thompson E Villedieu JET EFDA Contributors
The aim of the JET ITER-like Wall Project was to provide JET with the plasma facing material combination now selected for the DT phase of ITER (bulk beryllium main chamber limiters and a full tungsten divertor) and, in conjunction with the upgraded neutral beam heating system, to achieve ITER relevant conditions. The design of the bulk Be plasma fa…
Published