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…
PublishedM. Bécoulet G. Huysmans X. Garbet E. Nardon D. Howell A.Garofalo M. Schaffer T. Evans K. Shaing A. Cole J.-K. Park P. Cahyna
Non-linear reduced MHD modelling of the response of a toroidally rotating plasma on Resonant Magnetic Perturbations (RMPs) is presented for DIII-D and ITER typical parameter. The non-linear cylindrical reduced MHD (RMHD) code was adapted to take into account toroidal rotation and plasma braking mechanisms such as resonant braking (~jxB) and the Neo…
PublishedM. Barnes I. G. Abel W. Dorland D. R. Ernst G. W. Hammett P. Ricci B. N. Rogers A. A. Schekochihin T. Tatsuno
A set of key properties for an ideal dissipation scheme in gyrokinetic simulations is proposed, and implementation of a model collision operator satisfying these properties is described. This operator is based on the exact linearized test-particle collision operator, with approximations to the field-particle terms that preserve conservation laws an…
PublishedK. G. McClements & R. J. Mckay
Impurity ions with sufficiently high mass in toroidally-rotating tokamak plasmas are deeply trapped by a centrifugal potential well in the outer plasma midplane, with a bounce period that is shorter than both the bounce period of magnetically-trapped ions and the collision time. As a result trace impurity ions can undergo collisional transport at a…
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-D Hua IT Chapman SD Pinches RJ Hastie The Mast Team
‘Advanced tokamak’ (AT) scenarios were developed with the aim of reaching tokamak steady-state operation. They are designed to optimise the self-generated current, whilst also reaching sufficiently high plasma pressure to achieve optimal fusion reaction rates. AT scenarios exhibit non-monotonic to flat safety factor profiles (q, a measure of th…
PublishedE.S. Marmar A. Bader M. Bakhtiari H. Barnard W. Beck I. Bespamyatnov A. Binus P. Bonoli B. Bose M. Bitter I. Cziegler G. Dekow et al.
This paper summarizes highlights of research results from the Alcator C-Mod tokamak covering the period 2006 through 2008. Active flow drive, using mode converted waves in the ion cyclotron range of frequencies (ICRF), has been observed for the first time in a tokamak plasma, using a mix of D and 3 He ion species; toroidal and poloidal flows are dr…
PublishedI. Pusztai T. Fülöp J. Candy R. J. Hastie
The stability of ion temperature gradient ITG modes and the quasilinear fluxes driven by them are analyzed in weakly collisional tokamak plasmas using a semianalytical model based on an approximate solution of the gyrokinetic equation, where collisions are modeled by a Lorentz operator. Although the frequencies and growth rates of ITG modes far fro…
PublishedI. Monakhov M. Graham T. Blackman M.L. Mayoral M. Nightingale et al.
The External Conjugate-T (ECT) matching system was successfully commissioned on two A2 ICRH antennas at JET in 2009. The system allows trip-free injection of RF power into ELMy H-mode plasmas in the 32-52 MHz band without antenna phasing restrictions. The ECT demonstrates robust and predictable performance and high load-tolerance during routine ope…
Published