-
UKAEA-CCFE-PR(25)3782024
We develop an atomic cluster expansion (ACE) interatomic potential for lithium that accurately models both the solid and liquid phase and the corresponding melting point. The predicted properties for both phases are in close agreement with density functional theory (DFT) and experimental data from literature. The potential is able to capture the…
-
UKAEA-CCFE-PR(25)3752025
The National Spherical Torus Experiment (NSTX) at the Princeton Plasma Physics Laboratory in the United States, and the Mega Ampere Spherical Tokamak (MAST) at the United Kingdom Atomic Energy Authority in the United Kingdom, and their respective upgrades (NSTX-U and MAST-U) are two mega-amp class spherical tokamak fusion devices that have operated…
-
UKAEA-CCFE-PR(25)3742025
Microwave diagnostics will be one of the few diagnostic techniques that can be operated in future fusion devices. In the past, they have contributed significantly to the understanding of the plasma dynamics, in particular electron cyclotron emission (ECE) and reflectometry. While these provide 1D measurements of plasma electron temperature and…
-
UKAEA-CCFE-PR(25)3762024
Magnetic stochastic perturbations can strongly influence cross-field transport in high β tokamak plasmas. The impact of stochastic magnetic fields on electron heat transport in MAST/MAST-U is studied over a range in collisionality. Different formulae, based on the Rechester-Rosenbluth and the semi-empirical Rebut-Lallia-Walkins models, are used to…
-
UKAEA-CCFE-PR(25)3732024
Two closely-related candidate surrogate models for global tokamak plasma dynamics both exhibit spiking behaviour, which may be understood using concepts from the classical problem of particle motion in a well of potential energy. Numerical work indicates that when there is coupled evolution of the well’s properties, there is the bifurcation ca…
-
UKAEA-CCFE-PR(25)3712024
Instabilities of Alfvén eigenmodes (AEs) are of significant concern because they can enhance the cross-field transport of alpha particles beyond the neoclassical level in magnetic fusion plasmas. The threshold value of alpha-particle pressure for exciting AEs depends critically on the damping rate of AEs. The damping mechanisms include kinetic dam…
-
UKAEA-CCFE-PR(25)3722024
The crystal plasticity-based finite element method is widely used as it allows complex microstruc8 tures to be simulated and for direct comparison with experiments. In this paper, we introduce and demonstrate a new crystal plasticity code (OXFORD-UMAT for Abaqus® 9 ), which we have 10 made freely available online to encourage other …
-
UKAEA-CCFE-PR(25)3702023
14C is produced from the activation of N and O with high-energy neutrons. Due to its long half-life, high residence time in the environment and ease of assimilation into living matter, it is a major concern for the transportation of activated material and disposal of radioactive waste materials. This paper reports the discrepancy in the 14C prod…
-
UKAEA-CCFE-PR(25)3692024
Plasma detachment in tokamaks is useful for reducing heat flux to the target. It involves interactions of the plasma with impurities and neutral particles, leading to significant losses of plasma power, momentum, and particles. Accurate mapping of plasma emissivity in the divertor and X-point region is essential for assessing the rel…
-
UKAEA-CCFE-PR(25)3682024
This research utilizes established cyclic deformation models to simulate the Bauschinger effect observed in copper monocrystal cantilever experiments during the initial bending and straightening phases. Crystal plasticity finite element simulations employing Armstrong-Frederick, Orowan-Sleeswyk, and various other backstress models have failed to…
Showing 31 - 40 of 2477 UKAEA Paper Results