139 citations · 369 across the 12 of their papers we have counts for
12 papers
Effect of mismatch on Doppler backscattering in MAST and MAST-U plasmas
Valerian H. Hall-Chen, Felix I. Parra, Jon C. Hillesheim +14
The Doppler backscattering (DBS) diagnostic, also referred to as Doppler reflectometry, measures turbulent density fluctuations of intermediate length scales. However, when the bea…
Validating and optimising mismatch tolerance of Doppler backscattering measurements with the beam model
Valerian H. Hall-Chen, Julius Damba, Felix I. Parra +11
We use the beam model of Doppler backscattering (DBS), which was previously derived from beam tracing and the reciprocity theorem, to shed light on mismatch attenuation. This atten…
Three-Dimensional Inhomogeneity of Electron-Temperature-Gradient Turbulence in the Edge of Tokamak Plasmas
J. F. Parisi, F. I. Parra, C. M. Roach +15
Nonlinear multiscale gyrokinetic simulations of a Joint European Torus edge pedestal are used to show that electron-temperature-gradient (ETG) turbulence has a rich three-dimension…
Beam model of Doppler backscattering
Valerian H Hall-Chen, Felix I Parra, Jon C Hillesheim
We use beam tracing -- implemented with a newly-written code, Scotty -- and the reciprocity theorem to derive a model for the linear backscattered power of the Doppler Backscatteri…
Toroidal and slab ETG instability dominance in the linear spectrum of JET-ILW pedestals
Jason F. Parisi, Felix I. Parra, Colin M. Roach +9
Local linear gyrokinetic simulations show that electron temperature gradient (ETG) instabilities are the fastest growing modes for in the steep gradient regio…
Global scaling of the heat transport in fusion plasmas
Sara Moradi, Johan Anderson, Michele Romanelli +2
A global heat flux model based on a fractional derivative of plasma pressure is proposed for the heat transport in fusion plasmas. The degree of the fractional derivative of the he…
Gyrokinetic analysis and simulation of pedestals, to identify the culprits for energy losses using fingerprints
M. Kotschenreuther, X. Liu, D. R. Hatch +14
Fusion performance in tokamaks hinges critically on the efficacy of the Edge Transport Barrier (ETB) at suppressing energy losses. The new concept of fingerprints is introduced to…
Direct Gyrokinetic Comparison of Pedestal Transport in JET with Carbon and ITER-Like Walls
D. R. Hatch, M. Kotschenreuther, S. M. Mahajan +8
This paper compares the gyrokinetic instabilities and transport in two representative JET pedestals, one (pulse 78697) from the JET configuration with a carbon wall (C) and another…
Overview of recent physics results from MAST
A Kirk, J Adamek, RJ Akers +160
New results from MAST are presented that focus on validating models in order to extrapolate to future devices. Measurements during start-up experiments have shown how the bulk ion…
Dependence of intrinsic rotation reversals on collisionality in MAST
J. C. Hillesheim, F. I. Parra, M. Barnes +6
Tokamak plasmas rotate even without external injection of momentum. A Doppler backscattering system installed at MAST has allowed this intrinsic rotation to be studied in Ohmic L-m…
Measurement of high-k density fluctuation wavenumber spectrum in MAST and Doppler backscattering for spherical tokamaks
J. C. Hillesheim, N. A. Crocker, W. A. Peebles +7
The high-k () wavenumber spectrum of density fluctuations has been measured for the first time in MAST [B. Lloyd et al, Nucl. Fusion 43, 1665 (…
Current understanding of the processes underlying the triggering of and energy loss associated with type I ELMs
A. Kirk, D. Dunai, M. Dunne +7
The type I ELMy H-mode is the baseline operating scenario for ITER. While it is known that the type I ELM ultimately results from the peeling-ballooning instability, there is growi…