Journals

Showing 11 - 20 of 1464 Journals Results
2020
UKAEA-CCFE-PR(20)78

During an accident with loss-of-coolant and air ingress in DEMO, the temperature of tungsten first wall cladding may exceed 1000oC and remain for months leading to tungsten oxidation. The radioactive tungsten oxide can be mobilized to the environment at rates of 10 – 150 kg per hour. Smart tungsten-based alloys are under development to…

Preprint Purchase
2020
UKAEA-CCFE-PR(20)79

Point defects in body-centred cubic Fe, Cr and concentrated random magnetic Fe-Cr are investigated

using density functional theory and theory of elasticity. The volume of a substitutional

Cr atom in ferromagnetic bcc Fe is approximately 18% larger than the…

Preprint
2020
UKAEA-CCFE-PR(20)76

Abstract—In tokamak operation the control of dangerous MHD instabilities, possibly in r-t scenarios, must rely on prompt robust diagnostics of the state and stability of the system. The set of magnetic signals measured on the outside of the plasma bound- ary, bas…

Preprint
2020
UKAEA-CCFE-PR(20)77

Anisotropy and some limiting toroidal flow effects on the stability of non resonant ideal magnetohydrodynamic modes in hybrid shaped tokamak plasmas are investigated within the ideal MHD infernal mode framework. Such effects are found to alter the plasma magnetic well/hill, which can be interpreted as imparing the average curvature, and the strengt…

Preprint
2020
UKAEA-CCFE-PR(20)75

The Gyrokinetic Toroidal Code (GTC) has been used to study Toroidal Alfven Eigenmodes (TAEs) in high-
performance plasmas. Experiments performed at the Joint European Torus, where TAEs were driven by
energetic particles arising from Neutral Beams, ion cyclotron resonant heating and resonantly excited by
ded…

Preprint Published
2020
UKAEA-CCFE-PR(20)74

The impacts of ions and neutrons in metals causes cascades of atomic collisions that expand and shrink, leaving microstructure defect debris, i.e. interstitial or vacancy clusters or loops of different sizes. In [A. De Backer, A. E. Sand, K. Nordlund, L. Lun´eville, D. Simeone, and S. L. Dudarev. EPL, 115(2):26001, 2016.], we described a method…

Preprint Published
2020
UKAEA-CCFE-PR(20)73

The evolution of the defect microstructure in materials at high temperature is dominated by
diffusion-mediated interactions between dislocations, vacancy clusters and surfaces. This gives rise
to complex non-linear couplings between interstitial and vacancy-type dislocation loops, cavities
and the field of diffusing vacancies t…

Preprint Published
2020
UKAEA-CCFE-PR(20)72

Self-ion bombardment of pure tungsten with ion energies of 2 MeV is used to mimic the defects created by neutrons in a fusion reactor. Electron microscopy is used to characterize the microstructure of samples. Thermal Desorption Spectrometry (TDS) is performed on deuterium implanted samples in order to estimate deuterium inventory as function of da…

Preprint
2020
UKAEA-CCFE-PR(20)71

Small and shear punch testing are promising techniques that can be applied as virtually non-destructive tools to monitor in-service components and maximise the amount of information that can be obtained from limited in situ material; several mechanical properties can be determined at critical locations of a component with no need for repair welds. …

Preprint