UKAEA Journals

Showing 1 - 10 of 20 Journals Results
2021
UKAEA-CCFE-PR(21)75

Eurofer97 steel is a primary structural material for the plasma facing-components of future fusion reactors. Laser welding is a promising technique that can overcome the challenges of remote handling and maintenance. However, the interaction of the induced residual stress distribution with the heterogeneous microstructure may degrade the mechani…

Preprint
2021
UKAEA-CCFE-PR(21)60

Using atomistic simulations based on the creation-relaxation algorithm, we explore the evolution of microstructure in irradiated zirconium over a broad range of radiation exposure. In agreement with experimental observations, we find that at relatively low temperatures, microstructure evolves towards an asymptotic dynamic steady state forming at…

Preprint Published
2021
UKAEA-CCFE-PR(21)49

Using a combination of simulated data and pyrite isotopic reference materials, we have refined a methodology to obtain quantitative δ34S measurements from atom probe tomography (APT) datasets. This study builds on previous attempts to characterize relative 34S/32S ratios in gold containing pyrite using APT. We have also improved our understand…

Preprint
2021
UKAEA-CCFE-PR(21)48

Atom probe tomography and related methods probe the 3D architecture of a material. Which software tools microscopists use and how these tools are connected into work flows makes a substantial contribution to the accuracy and precision of a materials characterization experiment. Typically, the tools of a specific community adapt results and methods …

Preprint
2020

A robust impurity detection and tracking code, able to generate large sets of dust tracks from tokamak camera footage, is presented. This machine learning–based code is tested with cameras from the Joint European Torus, Doublet-III-D, and Magnum-PSI and is able to generate dust tracks with a 65–100% classification accuracy. Moreover, the number…

Published
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 at ~…

Preprint Published
2019
UKAEA-CCFE-PR(20)06

We present a morphological analysis of atom probe data of nanoscale microstructural features, using methods developed by the astrophysics community to describe the shape of superclusters of galaxies. We describe second-phase regions using Minkowski functionals, representing the regions’ volume, surface area, mean curvature and Euler characteristi…

Preprint Purchase
2019
UKAEA-CCFE-PR(19)67

Analysis of the L-H and H-L transition power thresholds (Pth) and pedestal parameters are presented for the Mega Ampere Spherical Tokamak (MAST). The dependencies of Pth on the average, core plasma electron density, X-point height and plasma current are described. Increasing X-point distance from the divertor floor over 10-12 cm, is found to inc…

Preprint Published
2019
UKAEA-CCFE-PR(19)39

Fusion is one of very few options for sustainable, baseload power to the grid that is necessary to meet the energy needs of future generations. The tokamak is the most advanced approach to fusion and, with the construction of ITER, we are approaching power plant conditions. While commercialisation of this key technology is a main driver for tokamak…

Preprint Published
2019
UKAEA-CCFE-PR(19)18

A numerical survey of the plasma response in ASDEX Upgrade ELM control experiments is conducted, to clarify the role of triangularity in the suppression mechanism. The pedestal pressure increases with triangularity consistent with previous work [2], which modestly boosts the peeling response. However, the peeling response decreases with increasi…

Preprint Published