Mark Fedorov Jan S. Wrobel Antonio Fernandez-Caballero Krzysztof J. Kurzydlowski Duc Nguyen-Manh
Multi-component alloy Fe-Cr-Mn-Ni is a promising new candidate system not only because of its potential application as structural materials beyond conventional austenitic steels but also for fundamental physics role played by Mn element in Fe-Cr-Ni based alloys. In this work, the phase stability of magnetic face-centered cubic (fcc) Fe-Cr-Mn-Ni sys…
Preprint PublishedK. Arakawa M.-C. Marinica S. Fitzgerald L. Proville D. Nguyen-Manh S. L. Dudarev P.-W. Ma T. D. Swinburne A. M. Goryaeva T. Yamada T. Amino S. Arai Y. Yamamoto K. Higuchi N. Tanaka H. Yasuda T. Yasuda H. Mori
The diffusion of defects in crystalline materials governs macroscopic behaviour in a wide range of processes, including alloying, precipitation, phase transformation, and creep. In real materials, intrinsic defects are unavoidably bound to static trapping centres such as impurity atoms, meaning that their diffusion is controlled by the de-trapping …
PublishedG. Bongiovì S. Grazioso S. Jimenez
Systems Engineering (SE) allows addressing the design of complex systems from a holistic standpoint, starting from the early stage of development until the end of its lifetime. Using a SE approach, all the stakeholders’ needs can be considered, and different design alternatives can be proposed, taking into account requirements coming from all the…
Preprint PublishedY. Q. Wang S. J. Clark B. Cai D. Alba Venero K. Yan M. Gorley E. Surrey D. G. McCartney S. Sridhar P. D. Lee
Ti-containing micro-alloyed steels are often alloyed with molybdenum (Mo) to gain superior ageing-resistance through reduced nano-precipitate coarsening, although the exact mechanism is still disputed. Using small angle neutron scattering (SANS), we characterize precipitate composition and coarsening in Ti micro-alloyed steels with and without M…
Preprint PublishedA.J. Cackett C.D. Hardie J.J.H. Lim E. Tarleton
We analyse spherical nanoindentation of single crystal copper using two different indenter tips of radii 7.4 and 27 um. The surface deformation surrounding the indents was measured using atomic force microscopy and the elastic rotation fields under the indents were measured using electron diffraction and transmission techniques. Using the measured …
Preprint PublishedD.J. Battaglia S.P. Gerhardt A. Kirk L. Kogan J.E. Menard D. Mueller A.J. Thornton
Reduced models coupled to time-dependent axisymmetric vacuum field calculations are used to develop the prefill and feed-forward coil current targets required for reliable direct induction (DI) startup on the new MA-class spherical tokamaks, MAST-U and NSTX-U. The calculations are constrained by operational limits unique to each device, such as the…
Preprint PublishedR. B. Morales S. Heuraux R. Sabot S. Hacquin
All density profile reconstruction techniques for both O-mode and X-mode are based on the assumption that the cut-off frequency profile is monotonic. However, there are many sources of perturbations to the plasma that generate hollow areas in the cut-off frequency profile, breaking the aforementioned assumption and causing a significant immediate r…
PreprintM Sasaki Y Kawachi R O Dendy H Arakawa N Kasuya F Kin K Yamasaki S Inagaki
The novel technique of dynamical mode decomposition (DMD) is applied to the outputs of a numerical simulation of Kelvin-Helmholtz turbulence in a cylindical plasma, so as to capture and quantify the time evolution of the dominant nonlinear structures. These structures comprise rotationally symmetric deformations together with spiral patterns, which…
Preprint PublishedGeorge Fulton Artem Lunev
Tungsten, a plasma-facing material for future fusion reactors, may be exposed to air during abnormal operation or accidents. Only limited information is available on the evolution of related oxide phases. This work addresses the effect of substrate orientation on structural variations of tungsten oxides. Annealing experiments in an argon-oxygen atm…
Preprint PublishedH. J. C. Oliver S. E. Sharapov B. N. Breizman A. K. Fontanilla D. A. Spong D. Terranova JET Contributors
Alfven eigenmodes driven by energetic particles are routinely observed in tokamak plasmas. These modes consist of poloidal harmonics of shear Alfven waves coupled by inhomogeneity in the magnetic field. Further coupling is introduced by 3D inhomogeneities in the ion density during the assimilation of injected pellets. This additional coupling modi…
Preprint Published