Bin Zhu Nathanael Leung Winfried Kockelmann Saurabh Kabra Andrew J. London Michael Gorley Mark J. Whiting Yiqiang Wang Tan Sui
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 mechanical…
Preprint PublishedAndrew R. Warwick Max Boleininger Sergei L. Dudarev
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 PublishedPhillip Gopon James O. Douglas Frederick Meisenkothen Jaspreet Singh Andrew J. London Michael P. Moody
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…
PreprintMarkus Kuhbach Andrew J. London Jing Wang Daniel K. Schreiber FranciscaMendez-Martin Iman Ghamarian Huma Bilal Anna Ceguerra
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 …
PreprintAndrew Davis Aleksander Dubas Rubin Otin
The field of fusion energy is about to enter the ITER era, for the first time we will have access to a device capable of producing 500 MW of fusion power, with plasmas lasting more than 300 seconds and with core tem- perature…
Preprint PublishedC. Cowley P. Fuller Y. Andrew L. James L. Simons M. Sertoli S. Silburn A. Widdowson JET contributors
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…
PublishedAndrew Lahiff Shaun de Witt Miguel Caballer Giuseppe La Roca Stanislas Pamela David Coster
Access to both High Throughput Computing (HTC) and High Performance Computing (HPC) facilities is vitally important to the fusion community, not only for plasma modelling but also for advanced engineering and design, materials research, rendering, uncertainty quantification and advanced data analytics for engineering operations. The computing re…
Preprint PublishedSuchandrima Das Daniel R. Mason Peter M. Derlet Sergei L. Dudarev Andrew London Hongbing Yu Nicholas Phillips David Yang Kenichiro Mizohata Ruqing Xu Felix Hofmann
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 PublishedDaniel R. Mason Andrew J. London
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 PublishedYasmin Andrew Jan-Peter Baehner Ronan Battle Tomas Jirman and the MAST team
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