G. 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 PublishedA.R. Field D. Dunai Y-C Ghim P. Hill B. Mcmillan C.M. Roach S. Saarelma A.A. Schekochihin S. Zoletnik The Mast Team
Observations of ion-scale density turbulence of relative amplitude are available on the Mega Amp Spherical Tokamak (MAST) using a 2D (8 radial × 4 poloidal channel) imaging Beam Emission Spectroscopy (BES) diagnostic. Spatial and temporal characteristics of this turbulence, i.e., amplitudes, correlation times, radial and perpendicular correlation …
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…
PublishedA.R. Field D. Dunai R. Gaffka Y.-C. Ghim I. Kiss et al.
A new beam emission spectroscopy turbulence imaging system has recently been installed onto the MAST spherical tokamak. The system utilises a high-throughput, direct coupled imaging optics, and a single large interference filter for collection of the Doppler shifted emission from the ~2 MW heating beam of ~70 keV injection energy. The collected lig…
PublishedYoung-Chul Ghim(Kim) A. R. Field S. Zoletnik D. Dunai
The beam emission spectroscopy BES turbulence diagnostic on MAST is to be upgraded in June 2010 from a one-dimensional trial system to a two-dimensional imaging system 8 radial 4 poloidal channels based on a newly developed avalanche photodiode array camera. The spatial resolution of the new system is calculated in terms of the point spread functio…
Published