Showing 1 - 10 of 394 Journals Results
2021
UKAEA-CCFE-PR(21)08
H. J. Sun E. Wolfrum T. Eich A. Kallenbach P. Schneider B. Kurzan U. Stroth the ASDEX Upgrade Team
A survey of the correlation between temperature and density gradient lengths ( and ) has been performed for the near SOL regions in the ASDEX Upgrade tokamak. In common with previous studies, the near SOL temperature and density gradient length ratio, , is found to be close to unity across a wide range of plasmas. However, it is found that it is po…
Preprint Published2021
UKAEA-CCFE-PR(21)02
Guanqi Dong Yueqiang Liu Xi Chen Guangzhou Hao Yi Liu Shuo Wang Neng Zhang Guoliang Xia
In quiescent H-mode (QH-mode) regime, edge harmonic oscillations (EHOs) are believed to provide necessary radial transport to prevent occurrence of large edge localized modes. A systematic modeling study is performed here on the low-n EHOs in a DIII-D QH-mode plasma [Chen et al. 2016 Nucl. Fusion 56 076011], by utilizing the MARS-Q code [Liu et a…
Preprint2020
UKAEA-CCFE-PR(20)141
Pui-Wai Ma S L Dudarev
Using ab initio density function theory calculations, we have determined the structure of self-interstitial atom (SIA) defects in the most commonly occurring face-centred cubic (FCC) metals. The most stable SIA defects in Al, Ca, Ni, Cu, Pd and Ag are the {100} dumbbells whereas octahedral SIA configurations have the lowest energy in Pt, R…
Preprint Published2020
UKAEA-CCFE-PR(20)138
P. Svensson O. Embreus S. L. Newton K. Särkimäki O. Vallhagen T. Fülöp
The electron runaway phenomenon in plasmas depends sensitively on the momentum space dynamics. However, efficient simulation of the global evolution of systems involving runaway electrons typically requires a reduced fluid description. This is needed for example in the design of essential runaway mitigation methods for tokamaks. In this paper, w…
Preprint2020
UKAEA-CCFE-PR(20)132
H.E. Coules S. O. Nneji J. A. James S. Kabra J. N. Hu Y. Wang
Mechanical constitutive models of metals undergoing deformation in three dimensions can be challenging to validate without loss of generality. For example, creep-induced stress relaxation in stainless steels has previously been studied using axisymmetric notched-bar tests which control the triaxiality of the initial stress state. However, such expe…
Preprint2020
UKAEA-CCFE-PR(20)130
A.Kareer E. Tarleton C. Hardie S.V.Hainsworth A.J.Wilkinson
In this paper we investigate the residual deformation field in the vicinity of nano-scratch experiments generated using two tip geometries in a (100) Cu single crystal. We compare the deformation with that from indentation, in an attempt to understand the mechanisms of deformation in tangential sliding. The lattice rotation fields are mapped exp…
Preprint Purchase2020
UKAEA-CCFE-PR(20)103
Federico Baraglia Pui-Wai Ma
We develop a dynamic model for the evolution of an ensemble of hundreds of interacting irradiation-induced mobile nanoscale defects in a micrometre size sample. The model uses a Langevin defect dynamics approach coupled to a finite element model, treated using the superposition method. The elastic field of each defect is described by its elastic…
Preprint2020
UKAEA-CCFE-PR(20)76
E. Lazzaro L. Bonalumi S. Nowak D. Brunetti
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 boundary, based on the Zakharov-Shafranov, Shkarowsky, Wootton (ZSSW) current moments has been always used f…
Preprint Published2020
UKAEA-CCFE-PR(20)70
V.D. Vijayanand M. Mokhtarishirazabad J. Peng Y. Wang M. Gorley D.M. Knowles M. Mostafavi
Determining tensile properties from small punch test is being pursued actively in the nuclear industry due to the limited volume of material such tests use compared with standard tests which can be critical when considering active or development samples. One of the crucial challenges in harnessing the full potential of this technique is formulat…
Preprint Published2020
UKAEA-CCFE-PR(20)21