P. Mantica C. Angioni C. Challis G. Colyer L. Frassinetti N. Hawkes T. Johnson M. Tsalas P. C. Devries J. Weiland B. Baiocchi M. N. A. Beurskens A. C. A. Figueiredo C. Giroud J. Hobirk E. Joffrin E. Lerche V. Naulin A. G. Peeters A. Sal
New transport experiments on JET indicate that ion stiffness mitigation in the core of a rotating plasma, as described by Mantica et al. [ Phys. Rev. Lett. 102, 175002 (2009) ] results from the combined effect of high rotational shear and low magnetic shear. The observations have important implications for the understanding of improved ion core con…
PublishedVolker Naulin Jens Juul Rasmussen Clemente Angioni Carine Giroud Marco Valisa Maria Ester Puiatti L. Carraro
Impurity transport is an important topic for ITER as impurity density in tlie core has to stay below a relative concentration of 5 x 10~^ [1] to reach ignition conditions. The reasons for that is mainly impurity radiation leading to cooling. In the edge region on the other hand site, higher impurity densities, going along with radiation energy loss…
PublishedM.G. Von Hellermann E.Delabie R.J.E. Jaspers W.Biel O.Marchuk H.P.Summers A.Whlteford C.Giroud N.C.Hawkes K.D.Zastrow
Charge exchange Recombination Spectroscopy (CXRS) plays a pivotal role in the diagnostics of hot fusion plasmas and is implemented currently in most of the operating devices. In the present report the main features of CXRS are summarized and supporting software packages encompassing "Spectral Analysis Code CXSFIT", "Charge Exchange Analysis Package…
PublishedY. Liang H. R. Koslowski P. R. Thomas E. Nardon B. Alper P. Andrew Y. Andrew G. Arnoux Y. Baranov M. Bécoulet M. Beurskens T. Biewer M. Bigi K. Crombe E. De La Luna P. De Vries W. Fundamenski S. Gerasimov C. Giroud M. P. Gryaznevich N.
Type-I edge-localized modes (ELMs) have been mitigated at the JET tokamak using a static external n 1 perturbation field generated by four error field correction coils located far from the plasma. During the application of the n 1 field the ELM frequency increased by a factor of 4 and the amplitude of the D signal decreased. The energy loss per ELM…
PublishedM. F. F. Nave H. R. Koslowski S. Coda J. Graves M. Brix R. Buttery C. Challis C. Giroud M. Stamp P. De Vries Jet-Feda Contributors
During a recent reversed toroidal field (B T) campaign at the Joint European Torus (JET), experiments were performed to investigate the effect on sawteeth of neutral beam injection (NBI)-driven toroidal plasma rotation counter to the direction of the toroidal plasma current and B T . A power scan at constant density has permitted analytical continu…
PublishedN. C. Hawkes B. C. Stratton T. Tala C. D. Challis G. Conway R. Deangelis C. Giroud J. Hobirk E. Joffrin P. Lomas P. Lotte J. Mailloux D. Mazon E. Rachlew S. Reyes-Cortes E. Solano K-D. Zastrow
Simultaneous current ramping and application of lower hybrid heating and current drive (LHCD) have produced a region with zero current density within measurement errors in the core of JET tokamak optimized shear discharges. The reduction of core current density is consistent with a simple physical explanation and numerical simulations of radial cur…
PublishedN. C. Hawkes B. C. Stratton T. Tala C. D. Challis G. Conway R. Deangelis C. Giroud J. Hobirk E. Joffrin P. Lomas P. Lotte J. Mailloux D. Mazon E. Rachlew S. Reyes-Cortes E. Solano K-D. Zastrow
Modern charge-coupled-device (CCD) detectors can achieve peak quantum efficiencies of 90%, compared with less than 10% for the photocathode of an electron multiplier. We report on laboratory tests of examples of these two detector technologies to evaluate their relative performance for precision Doppler spectroscopy of laboratory plasmas. The tests…
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