R.J. Nicholls D. Nguyen-Manh D.J.H. Cockayne S. Lazar
The unoccupied density of states is simulated for two different experimentally determined C 60 crystal structures. Several theoretical crystal structures are constructed to allow the effects of bond length and relative molecular orientation to be studied. It is found that both have an effect on the unoccupied states, and that the larger effect is c…
PublishedG A Cottrell R Kemp
In a rotating plasma, with co-neutral beam injection (NBI), the Doppler shift of the NBI particles, as viewed in the frame of the plasma, can result in a significant reduction in the beam-driven (Ohkawa) current when the rotation is strong. The correction applies to the toroidal fast-ion current calculated for a non-rotating plasma and is independe…
PublishedV.F.Shevchenko M.R.O’Brien D.Taylor Mast Team
Electron Bernstein wave (EBW) assisted plasma current start-up has been demonstrated for the first time in a tokamak. It was shown that plasma currents up to 17 kA can be generated non- inductively by 100 kW of RF power injected. With optimized vertical field ramps, plasma currents up to 33 kA have been achieved without the use of solenoid flux. It…
PublishedI. T. Chapman M. F. De Bock S. D. Pinches M. R. Turnyanskiy Mast Team V. G. Igochine M. Maraschek G. Tardini Asdex Upgrade Team
Sawtooth behavior has been investigated in plasmas heated with off-axis neutral beam injection in ASDEX Upgrade [A. Herrmann and O. Gruber, Fusion Sci. Technol. 44 , 569 (2003)] and the Mega-Ampere Spherical Tokamak MAST [A. Sykes and et al. , Nucl. Fusion 41 , 1423 (2001)]. Provided that the fast ions are well confined, the sawtooth period is foun…
PublishedJ W Connor R J Hastie P Helander
Tearing mode stability is normally analysed using MHD or two-fluid Braginskii plasma models. However for present, or future, large hot tokamaks like JET or ITER the collisionality is such as to place them in the banana regime. Here we develop a linear stability theory for the resonant layer physics appropriate to such a regime. The outcome is a set…
PublishedM. K. Lilley B. N. Breizman S. E. Sharapov
The nonlinear evolution of waves excited by the resonant interaction with energetic particles, just above the instability threshold, is shown to depend on the type of relaxation process that restores the unstable distribution function. When dynamical friction dominates over diffusion in the phase space region surrounding the wave-particle resonance…
PublishedA. Lyssoivan R. Koch J.M. Noterdaeme V. Philipps D. Van Eester et al.
ITER and future superconducting fusion machines need efficient wall conditioning techniques for routine operation in between shots in the presence oi permanent high magnetic field for wall cleaning, surface isotope exchange and to control the in-vessel long term tritium retention. Ion Cyclotron Wall Conditioning (ICWC) based on the ICRF discharge i…
PublishedM. Zucchetti L. Di Pace L. El-Guebaly B.N. Kolbasov V. Massaut R. Pampin P. Wilson
Within the framework of the International Energy Agency, an international collaborative study on fusion radioactive waste has been initiated to examine the back end of the materials cycle as an important stage in maximizing the environmental benefits of fusion as an energy provider. The study addresses the management procedures for radioactive mate…
PublishedG. De Temmerman R.P. Doerner
The prediction of tritium retention in ITER relies on the extrapolation from present data. An empirical equation was proposed in (De Temmerman G. et al 2008 Nucl. Fusion 48 075008) to account for the influence of the beryllium deposition rate, the substrate temperature and the average energy of the deuterium neutrals on the deuterium retention. How…
PublishedA. J. Webster C. G. Gimblett
A potentially serious impediment to the production of energy by nuclear fusion in large tokamaks, such as ITER [R. Aymar, V. A. Chuyanov, M. Huguet, Y. Shimomura, ITER Joint Central Team, and ITER Home Teams, Nucl. Fusion 41, 1301 (2001)]and DEMO [D. Maisonner, I. Cook, S. Pierre, B. Lorenzo, D. Luigi, G. Luciano, N. Prachai, and P. Aldo, Fusion En…
Published