Peculiarity of highly radiating multi-impurity seeded H-mode plasmas on JET with ITER-like wall

A. Huber*, M. Wischmeier, M. Bernert, S. Wiesen, S. Glöggler, S. Aleiferis, S. Brezinsek, G. Calabro, P. Carvalho, V. Huber, G. Sergienko, E. R. Solano, C. Giroud, M. Groth, S. Jachmich, Ch Linsmeier, G. F. Matthews, A. G. Meigs, Ph Mertens, M. SertoliS. Silburn, G. Telesca

*Corresponding author for this work

Research output: Contribution to journalConference articleScientificpeer-review

1 Citation (Scopus)

Abstract

On JET with fully metallic first wall, highly radiative conditions with N2, Ne and Ar as well as their mixture as radiators are approached in high density H-mode plasmas. The confinement increases from H 98(y,2) = 0.65 in unseeded pulses with γ rad ∼ 30% to a value of H 98(y,2) = 0.75 at γ rad ∼ 50% with N2 injection. A degradation of the pedestal profile is compensated by steeper core n e and T e profiles. Further increase of γ rad with increase of the N2 seeding rate leads to a moderate confinement degradation which can be avoided by applying of combined impurity seeding. The enhancement of the plasma performance for the radiation fractions beyond 55% with the maximum value of H 98(y,2) = 0.78 is reached with combined N2 + Ne and N2 + Ar impurity injections. The observed intense, strongly localized radiation at the X-point inside the confined plasma in the scenarios with the highest radiated power fraction is interlinked to complete divertor detachment. In the JET-ILW, the X-point radiation is stable, reproducible and reversible.

Original languageEnglish
Article number014055
JournalPhysica Scripta
Volume2020
Issue numberT171
DOIs
Publication statusPublished - 1 Jan 2020
MoE publication typeA4 Article in a conference publication
EventInternational Conference on Plasma-Facing Materials and Components for Fusion Applications - Eindhoven, Netherlands
Duration: 20 May 201924 May 2019
Conference number: 17

Keywords

  • Detachment
  • Divertors
  • Impurities in plasmas
  • Power exhaust
  • Radiation
  • Tokamaks

Fingerprint Dive into the research topics of 'Peculiarity of highly radiating multi-impurity seeded H-mode plasmas on JET with ITER-like wall'. Together they form a unique fingerprint.

Cite this