UKAEA Journals

Showing 1 - 8 of 8 Journals Results
2020
UKAEA-CCFE-PR(20)113

Combining spatially resolved X-ray Laue diffraction with atomic-scale simulations, we observe how ion-irradiated tungsten undergoes a series of non-linear structural transformations with increasing irradiation exposure. Nanoscale defect-induced deformations accumulating above 0.02 displacements per atom (dpa) lead to highly fluctuating strains a…

Preprint Published
2020
UKAEA-CCFE-PR(20)102

Modification of the external tearing index, Δ’ext , by magnetic feedback is analytically investigated, for the purpose of controlling the resistive plasma resistive wall mode (RP-RWM). The matching method is pursued, by deriving expressions for the close-loop Δ’ext and by linking it to the counterpart from the inner layer. Various…

Preprint Published
2019
UKAEA-CCFE-PR(19)43

Body-centered cubic metals and alloys irradiated by energetic particles form highly mobile prismatic dislocation loops with a/2 {111} -type Burgers vectors. We show how to simulate thermal diffusion of prismatic loops using a discrete dislocation dynamics approach that explicitly includes the stochastic forces associated with ambient thermal fluctu…

Preprint Published
2017

Extensive modelling efforts of the plasma response to the resonant magnetic perturbation fields, utilized for controlling the edge localized mode (ELM), help to identify the edge-peeling response as a key factor, which correlates to the observed ELM mitigation in several tokamak devices, including MAST, ASDEX Upgrade, EAST, and HL-2A. The recently …

Published
2016
CCFE-PR(16)47

Resonant magnetic perturbations (RMP) have extensively been demonstrated as a plausible technique for mitigating or suppressing large edge localized modes (ELMs). Associated with this is a substantial amount of theory and modelling efforts during recent years. Various models describing the plasma response to the RMP fields have been proposed in the…

Preprint Published
2015
CCFE-PR(15)75

The magnetohydrodynamic-kinetic hybrid theory has been extensively and successfully applied for interpreting experimental observations of macroscopic, low frequency instabilities, such as the resistive wall mode, in fusion plasmas. In this work, it is discovered that an analytic version of the hybrid formulation predicts a bifurcation of the mode d…

Preprint Published
2005

Recently, it was shown that intermittency observed in magnetic fusion devices is caused by large-scales events with high radial velocity reaching about 1/10th of the sound speed s called avaloids or blobs [G. Antar and et al. , Phys. Rev. Lett. 87 065001 (2001)]. In the present paper, the poloidal distribution of turbulence is investigated on the M…

Published
2003

The nature of intermittency, long observed in magnetic fusion devices, was revisited lately [G. Antar et al. , Phys. Rev. Lett. 87 , 065001 (2001)]. It was shown that intermittency is caused by large-scale events with high radial velocity reaching about 1/10th of the sound speed. These type of structures were named ‘‘avaloids.’’ In the pres…

Published