UKAEA Journals

Showing 241 - 250 of 1621 Journals Results
2019
UKAEA-CCFE-PR(19)49

EDGE2D-EIRENE (the ‘code’) simulations show that radial electric field, Er, in the near scrape-off layer (SOL) of tokamaks can have large variations leading to a strong local E´B shear greatly exceeding that in the core region. This was pointed out in simulations of JET plasmas with varying divertor geometry, where the magnetic conf…

Preprint Published
2019
UKAEA-CCFE-PR(19)47

High bandwidth, high spatial resolution measurements of electron temperature, density and plasma potential are valuable for resolving turbulence in the boundary plasma of tokamaks. While conventional Langmuir probes can provide such measurements either their temporal or spatial resolution is limited: the former by the sweep rate necessary for obtai…

Preprint Published
2019
UKAEA-CCFE-PR(19)46

The effect of plasma shaping on scrape-off layer (SOL) plasma turbulence is investigated through a rigorous validation exercise. Two- and three-dimensional simulations of the SOL plasma dynamics in three TCV limited discharges are carried out with the GBS code. These discharges realize an almost circular magnetic equilibrium, an elongated equilibri…

Preprint Published
2019
UKAEA-CCFE-PR(19)45

The DEMO blanket attachment concept is challenging due to several factors: the harsh radiation environment, the thermal expansion, the electro-magnetic loads, the remote maintenance feasibility, and the accurate control of the alignment of the breeding blanket first wall during operation. There are two inboard and three outboard blanket segments pe…

Preprint Purchase
2019
UKAEA-CCFE-PR(19)44

The low energy structures of irradiation-induced defects have been studied in detail, as these determine the available modes by which a defect can diffuse or relax. As a result, there are many studies concerning the relative energies of possible defect structures, and empirical potentials are commonly fitted to or evaluated with respect to these en…

Preprint Published
2019
UKAEA-CCFE-PR(19)43

Body-centered cubic metals and alloys irradiated by energetic particles form highly mobile prismatic dislocation loops with a/2 {111} -type Burgers vectors. We show how to simulate thermal diffusion of prismatic loops using a discrete dislocation dynamics approach that explicitly includes the stochastic forces associated with ambient thermal fluctu…

Preprint Published
2019
UKAEA-CCFE-PR(19)42

High temperature, neutron irradiated single crystal tungsten, with a post irradiation composition of W-1.20±0.11at.%Re-0.11±0.05at.%Os-0.03±0.01at.%Ta was characterised using a combination of Atom Probe Tomography (APT) and Scanning Transmission Electron Microscopy (STEM). APT showed that within nanoscale clusters of Re/Os, the atomic density wa…

Preprint Purchase
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
2019
UKAEA-CCFE-PR(19)40

CALANIE (CALculation of ANIsotropic Elastic energy) program evaluates an elastic interaction correction to the total energy of a localized object, for example a defect in a solid material simulated using an {it ab initio} or molecular statics approach, resulting from the use of periodic boundary conditions. The correction, computed using a fully el…

Preprint Purchase
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 Purchase