UKAEA Journals

Showing 1 - 10 of 23 Journals Results
2018
UKAEA-CCFE-PR(20)129

Typically applied to non-linear simulations of MHD instabilities relevant to magnetically confined fusion, the JOREK code was originally developed with a 2D grid composed of isoparametric bi-cubic Bezier finite elements, that are aligned to the magnetic equilibrium of tokamak plasmas. To improve the applicability of these simulations, the grid-gene…

Preprint Published
2019
UKAEA-CCFE-PR(20)07

ELM simulations for the MAST-U Super-X tokamak have been obtained, using the JOREK code. The JOREK visco-resistive MHD model has been used to obtain comparisons of divertor configurations. The simulations show a factor 10 decrease in the peak heat flux to the outer target of the Super-X in comparison to a conventional divertor configuration. A roll…

Preprint Published
2019
2019
UKAEA-CCFE-PR(19)53

In toroidal magnetic confinement devices, such as tokamaks and stellarators, neoclassical transport is usually an order of magnitude larger than its classical counterpart. However, when a high-collisionality species is present in an stellarator optimized for low Pfirsch-Schlüter current, its classical transport can be comparable to the neoclassica…

Preprint Published
2019
UKAEA-CCFE-PR(19)41

A new facility to study the interaction of hydrogen isotopes with nuclear fusion relevant first wall materials, its retention and release, has been produced. The new facility allows implanting a range of gases into samples, including tritium. Accurate study of isotope effects, such as the isotopic exchange in damaged microstructure, has previously …

Preprint Published
2018
UKAEA-CCFE-PR(19)04

Avoiding impurity accumulation is a requirement for steady-state stellarator operation. The accumulation of impurities can be heavily affected by variations in their density on the flux-surface. Using recently derived semi-analytic expressions for the transport of a collisional impurity species with high-Z and flux-surface density-variation in t…

Preprint Published
2018
UKAEA-CCFE-PR(18)55

A long-term high-temperature testing stress rig has been designed and fabricated for performing in situ neutron diffraction tests at the ENGIN-X beamline, ISIS facility in the UK. It is capable of subjecting metals to high temperatures up to 800°C and uniaxial loading under different boundary conditions including constant load, constant s…

Preprint Published
2018
UKAEA-CCFE-PR(18)44

High-Z impurities in magnetic confinement devices are prone to develop density variations on the fluux-surface, which can significantly affect their transport. In this paper, we generalize earlier analytic stellarator calculations of the neoclassical radial impurity flux in the mixed-collisionality regime (collisional impurity and low-collisionalit…

Preprint Published
2018
UKAEA-CCFE-PR(18)9

Elastic follow-up is a mechanical boundary condition lying between constant load and constant strain control. It exists in many engineering components operating at high temperature and can result in dramatically different creep stress relaxation and strain accumulation rates in a localized region of a component. We have performed creep tests under …

Preprint Published