Confinement and Edge Studies
Towards Low r* and n* at JET
I. Nunes, P.J. Lomas, D.C. McDonald, G. Saibene, R. Sartori, I. Voitsekhovitch,
M. Beurskens, G. Arnoux, A. Boboc, T. Eich, C. Giroud, S Heureux,
E de la Luna, G. Maddison, A.C.C. Sips, H. Thomsen, T.W. Versloot
and JET EFDA contributors
The size and capability of JET to reach high plasma current and field enables a study of
the plasma behaviour at ion Larmor radius and collisionality values approaching those of ITER.
In this paper such study is presented. The achievement of stationary type I ELMy H-modes at
high current proved to be quite challenging. As the plasma current was increased, it became
more difficult to achieve stationary conditions. Nevertheless, it was possible to achieve stable
operation at high plasma current (up to 4.5MA) and low
q95 (2.65-3) at JET. One of the main reasons
to revisit the high plasma current experiments done in 1997 is the higher power available
and he improvement of the pedestal diagnostics. Indeed, compared with previous results, higher
stored energy was achieved but confinement was still degraded. The causes of this
confinement degradation are discussed in the paper.
Preprint of Paper to be submitted for publication in Proceedings of the
23rd IAEA Fusion Energy Conference,
Daejon, Republic of Korea.
(10th October 2010 - 16th October 2010)