H. Chen N. C. Hawkes L. C. Ingesson M. Von Hellermann K.-D. Zastrow et al.
Poloidally asymmetric distributions of nickel ions have been observed experimentally in Joint European Torus optimized shear tokamak plasmas following nickel laser injection experiments. Two types of asymmetries occur. In the first type of asymmetry, which has earlier been observed in high-confinement mode plasmas, nickel ions accumulate on the out…
PublishedC. G. Gimblett R. J. Hastie
The finite resistivity of the wall that surrounds any toroidal plasma confinement device can lead to a branch of instabilities known as the resistive wall mode (RWM). Theory indicates that the RWM is potentially activated whenever the plasma equilibrium is unstable with the wall placed at infinity. In particular, advanced tokamak power plant design…
PublishedJ. P. Graves K. I. Hopcraft
The recent Joint European Torus deuterium-tritium campaign has yielded ion-cyclotron-resonanceheated (ICRH) pulses during which both the sawtooth characteristics and the ICRH minority ion population both evolve substantially. At multiple times during each pulse, the evolution of the kinetic-fluid MHD energy is calculated from measurement of the ene…
PublishedR. V. Budny D. R. Ernst T. S. Hahm D. C. McCune J. P. Christiansen et al.
The edge-localized, high-confinement mode regime is of interest for future Tokamak reactors since high performance has been sustained for long durations. Experiments in the Joint European Tokamak [M. Keilhacker et al. , Nuclear Fusion 39 , 209 (1999)] have studied this regime using scans with the toroidal field and plasma current varied together in…
PublishedA. Sykes R. J. Akers L. C. Appel P. G. Carolan J.W. Connor N. J. Conway G. F. Counsell A. Dnestrovskij Yu.N. Dnestrovskij M. Gryaznevich P. Helander M. P. S. Nightingale C. Ribeiro C. M. Roach M. Tournianski M. J. Walsh H. R. Wilson The S
H -mode operation has been achieved in high current I p . 200 kA plasmas in the START spherical tokamak for both neutral-beam-injection-heated and Ohmic discharges. The transition to H mode features the development of well-defined edge pedestals in density and temperature, which signifies the formation of an edge-transport barrier, and associated e…
PublishedM. E. Dieckmann P. Ljung A. Ynnerman K. G. McClements
Collisionless quasiperpendicular shocks with magnetoacoustic Mach numbers exceeding a certain threshold are known to reflect a fraction of the upstream ion population. These reflected ions drive instabilities which, in a magnetized plasma, can give rise to electron acceleration. In the case of shocks associated with supernova remnants (SNRs), elect…
PublishedF. Durodié P. Lamalle G. Agarici G. Amarante W. Baity et al.
Whereas the essential components for power generation and transmission on an ITERsized ICRF plant are readily available, or only require modest extrapolation of present day ICRF systems, the 1C launching structure itself is regarded as needing development, validation and convincing demonstration. During the ITER-EDA, the design requirements of the …
PublishedD. A. Hartmann M.-L. Mayoral J. Heikkinen J.-M. Noterdaeme E. Righi et al.
On JET the coupling resistance averaged over the four straps of the A2 antennas in the Mark II GB divertor configuration was analyzed with particular emphasis on the plasma shape dependence. The measured values were compared with models for the coupling resistance of different levels of sophistication with the ultimate goal of supplying recipes on …
PublishedJ. B. Taylor
Relaxation is the result of turbulence in a plasma that behaves essentially as an ideal conducting fluid, but has a small resistivity and viscosity. These small effects are locally enhanced by the turbulence and lead to reconnection of magnetic field lines. This destroys an infinity of topological constraints, leaving only the total magnetic helici…
PublishedC. G. Gimblett R. J. Hastie
A model is developed to analyze the stabilization of the resistive wall mode (RWM) by plasma rotation. Central to the model is a cylindrical plasma that is ideal magnetohydrodynamic unstable in the absence of a wall, and possesses an internal resonance [J. M. Finn, Phys. Plasmas 2 , 198 (1995)]. This system is then a qualitative model for the actua…
Published