UKAEA Journals

Showing 1 - 8 of 8 Journals Results
2020
UKAEA-CCFE-PR(20)138

The electron runaway phenomenon in plasmas depends sensitively on the momentum space dynamics. However, efficient simulation of the global evolution of systems involving runaway electrons typically requires a reduced fluid description. This is needed for example in the design of essential runaway mitigation methods for tokamaks. In this paper, we p…

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2020
UKAEA-CCFE-PR(20)65

A novel approach using Bayesian inference has been implemented to interpret the filamentary dynamics measured by a Langmuir probe fixed to a reciprocating assembly on MAST. The model describes the system as a superposition of time-displaced filaments and a fixed background component. Each filament is parameterised in terms of a characteristic rise …

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The published version of this paper is currently under embargo and will be available on 20/10/2021
2012

In this paper, current profiles for plasma discharges on the mega-ampere spherical tokamak are directly calculated from pickup coil, flux loop, and motional-Stark effect observations via methods based in the statistical theory of Bayesian analysis. By representing toroidal plasma current as a series of axisymmetric current beams with rectangular cr…

Published
2010

Recently, Bayesian probability theory has been used at a number of experiments to fold uncertainties and interdependencies in the diagnostic data and forward models, together with prior knowledge of the state of the plasma, to increase accuracy of inferred physics variables. A new probabilistic framework, MINERVA, based on Bayesian graphical models…

Published
2008

An analytical Bayesian inversion of the JET interferometry line integrated densities into density profiles and associated uncertainty information, is demonstrated. These are used, with a detailed model of plasma polarimetry, to predict the rotation and ellipticity for the JET polarimeter. This includes the lateral channels, for over 45,000 time poi…

Published
2007

Principal techniques and trends in the validation and analysis of data in magnetic fusion research are described and examples of applications are given. Wellestablished methods to obtain key physical quantities are outlined, as well as newer techniques employing integrated analysis of multiple diagnostics to improve quality and extract additional i…

Published
2007

The development of the Single Aperture. Single Gap 1 MV accelerator (SINGAP) is being carried out on the 1 MV test bed at the DRFC, CEA Cadarache, France. This paper reports on the latest performance achieved with the prototype, "ITER-like" accelerator, 730 keV, 120 A/m 2 D", and of on-going measurements of the beam "halo" fraction, »10%. It revie…

Published