James Harrison RJ Akers SY Allan JS Allcock JO Allen L Appel M Barnes N Ben Ayed W Boeglin C Bowman J Bradley P Browning P Bryant M Carr M Cecconello CD Challis S Chapman IT Chapman GJ Colyer S Conroy NJ Conway M Cox G Cunningham RO Dendy W Dorland BD Dudson L Easy SD Elmore T Farley X Feng AR Field A Fil GM Fishpool M Fitzgerald
Recent results from MAST address key physics issues for ITER operations and the design of future devices, by advancing our understanding of through analysis of high-resolution data and numerical modelling. Modelling of the interaction between filaments with BOUT++ indicates filaments separated by more than 5x their width move independently, and …
Preprint PublishedG. J. Colyer A. A. Schekochihin F. I. Parra C. M. Roach M. A. Barnes Y. C. Ghim W. Dorland
In electrostatic simulations of MAST plasma at electron-gyroradius scales, using the local flux-tube gyrokinetic code GS2 with adiabatic ions, we find that the longtime saturated electron heat flux (the level most relevant to energy transport) decreases as the electron collisionality decreases. At early simulation times, the heat flux “quasisatura…
Preprint PublishedY.-C. Ghim A. A. Schekochihin A. R. Field I. G. Abel M. Barnes G. Colyer S. C. Cowley F. I. Parra D. Dunai S. Zoletnik The Mast Team
Beam emission spectroscopy (BES) measurements of ion-scale density fluctuations in the MAST tokamak are used to show that the turbulence correlation time, the drift time associated with iontemperature or density gradients, the particle (ion) streaming time along the magnetic field, and the magnetic drift time are consistently comparable, suggesting…
PublishedS. Saarelma P. Hill A. Bottino G. Colyer A.R. Field B. Mcmillan A. Peeters C.M. Roach Mast Team
Electrostatic gyrokinetic analyses are presented for an L-mode discharge with an internal transport barrier, from the spherical tokamak, MAST. Local and global microstability analysis finds similar linear growth rates for ion temperature gradient (ITG) driven modes. When the electron response is assumed to be adiabatic, growth rates are found to be…
PublishedP. 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…
Published