UKAEA Journals

Showing 1 - 10 of 10 Journals Results
2021
UKAEA-CCFE-PR(21)23

The work reported in this paper has already been presented internally by placement student Jacob Young at a MAST Physics and Technology meeting on December 17 2020. Therefore it does not require a paper review presentation. Please also note that the paper is proposed for inclusion in a special issue of Plasma Research Express linked to the recent I…

Preprint
2013

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…

Published
2013

New diagnostic, modelling and plant capability on the Mega Ampere Spherical Tokamak (MAST) have delivered important results in key areas for ITER/DEMO and the upcoming MAST Upgrade, a step towards future ST devices on the path to fusion currently under procurement. Micro-stability analysis of the pedestal highlights the potential roles of micro-tea…

Published
2013

In this paper, we extend the multiscale approach developed in Abel et al (2012 Rep. Prog. Phys. submitted) by exploiting the scale separation between ions and the electrons. The gyrokinetic equation is expanded in powers of the electron to ion mass ratio, which provides a rigorous method for deriving the reduced electron model. We prove that ion-sc…

Published
2010

Direct coupling between a transport solver and local, nonlinear gyrokinetic calculations using the multiscale gyrokinetic code TRINITY [M. Barnes, “TRINITY: A unified treatment of turbulence, transport, and heating in magnetized plasmas,” Ph.D. thesis, University of Maryland, (2008) eprint arXiv:0901.2868] is described. The coupling of the micr…

Published
2009

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…

Published
2008

A new analytically and numerically manageable model collision operator is developed specifically for turbulence simulations. The like-particle collision operator includes both pitch-angle scattering and energy diffusion and satisfies the physical constraints required for collision operators: it conserves particles, momentum, and energy, obeys Boltz…

Published
2008

We motivate the need to include collisional dissipation in gyrokinetic turbulence simulations, and constract criteria for a physically vaUd model of such dissipation. A new analytically manageable operator satisfying those criteria is presented and transformed into gyrokinetic variables. The form of conservation laws for collision operators in gyro…

Published
2007

This chapter reviews multichannel broadband measurement of the soft-X-ray radiation and total radiation in magnetically confined fusion plasma experiments. Common detector types used (including bolometers), details of their application, and interpretation of their measurements are described. An introduction is given to the application of computed t…

Published
2005

We have investigated the electronic structure of MoSi2, Mo5Si3, Mo3Si, and Mo(Si1−xAlx)2 alloys at a range of x values using a combination of valence-band x-ray photoelectron spectroscopy sVBXPSd and densityfunctional theory. We find good agreement between the experimental spectra and the calculated total densities of states. The observed differe…

Published