Published in

IOP Publishing, Nuclear Fusion, 10(53), p. 104002, 2013

DOI: 10.1088/0029-5515/53/10/104002

Links

Tools

Export citation

Search in Google Scholar

Overview of the JET results with the ITER-like wall

Journal article published in 2013 by R. de Angelis, Cp-H. Perez von Thun, C.-H. Perez von Thun, C. P. von Thun, Smg M. Gonzalez de Vicente, Gj J. van Rooij ORCID, G. de Arcas, Mr R. de Baar, E. de la Cal, E. de la Luna, Jl L. de Pablos, Pc C. de Vries, D. del-Castillo-Negrete, B. van Milligen, F. Romanelli ORCID and other authors.
This paper is made freely available by the publisher.
This paper is made freely available by the publisher.

Full text: Download

Green circle
Preprint: archiving allowed
Orange circle
Postprint: archiving restricted
Red circle
Published version: archiving forbidden
Data provided by SHERPA/RoMEO

Abstract

Following the completion in May 2011 of the shutdown for the installation of the beryllium wall and the tungsten divertor, the first set of JET campaigns have addressed the investigation of the retention properties and the development of operational scenarios with the new plasma-facing materials. The large reduction in the carbon content (more than a factor ten) led to a much lower Zeff (1.2-1.4) during L- and H-mode plasmas, and radiation during the burn-through phase of the plasma initiation with the consequence that breakdown failures are almost absent. Gas balance experiments have shown that the fuel retention rate with the new wall is substantially reduced with respect to the C wall. The re-establishment of the baseline H-mode and hybrid scenarios compatible with the new wall has required an optimization of the control of metallic impurity sources and heat loads. Stable type-I ELMy H-mode regimes with H98,y2 close to 1 and βN ∼ 1.6 have been achieved using gas injection. ELM frequency is a key factor for the control of the metallic impurity accumulation. Pedestal temperatures tend to be lower with the new wall, leading to reduced confinement, but nitrogen seeding restores high pedestal temperatures and confinement. Compared with the carbon wall, major disruptions with the new wall show a lower radiated power and a slower current quench. The higher heat loads on Be wall plasma-facing components due to lower radiation made the routine use of massive gas injection for disruption mitigation essential. © 2013 IAEA, Vienna.