Andrew Davis Aleksander Dubas Rubin Otin
The field of fusion energy is about to enter the ITER era, for the first time we will have access to a device capable of producing 500 MW of fusion power, with plasmas lasting more than 300 seconds and with core tem- perature…
Preprint PublishedJ. Leland S. Elmore A. Kirk H. v/d Meiden. J. Scholten S. Allan J. W. Bradley
Measurements made using flush-mounted Langmuir probes (FMPs) in tokamaks are difficult to interpret when operating at grazing angles of magnetic field incidence due to the effects of sheath expansion on the probe collection area. The super-X divertor on the upgraded Mega Ampere Spherical Tokamak (MAST-U) will have very shallow angles of magnetic fi…
Preprint PublishedH. 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 PublishedGuanqi 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…
Preprint PublishedR O Dendy B Chapman B C G Reman J W S Cook
Observations of radiation in the ion cyclotron range of frequencies from the KSTAR tokamak and LHD heliotron-stellarator show that energetic neutral beam injected (NBI) ion populations can relax collectively in the edge plasma near the injection point. The resulting radiation is ion cyclotron emission (ICE), whose spectrum has strongly suprather…
PreprintD. Moulton A. Fil O. Myatra B. Lipschultz B. Dudson
The paper reviews recent SOLPS modelling of long-legged divertors carried out by UKAEA and the University of York. The required upstream density required for detachment is predicted to scale inversely with the total flux expansion of the divertor, but experimentally this was not found to be the case on TCV. Interpretative SOLPS-ITER modelling sugge…
PreprintPui-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 PublishedP. 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, we p…
Preprint PublishedF. Militello L. Aho-Mantila R. Ambrosino T. Body H. Bufferand G. Calabro’ G. Ciraolo D. Coster G. Di Gironimo P. Fanelli N. Fedorczak A. Herrmann P. Innocente R. Kembleton J. Lilburne T. Lunt D. Marzullo S. Merriman D. Moulton A. Nielsen J. Omotani G. Ramogida H. Reimerdes M. Reinhart P. Ricci F. Riva A. Stegmeir F. Subba W. Suttrop P. Tamain M. Teschke A. Thrysoe W. Treutterer S. Varoutis M. Wensing A. Wilde M. Wischmeier L.Y. Xiang
A thorough physics and engineering analysis of alternative divertor configurations is carried out by examining benefits and problems by comparing the baseline single null solution with a Snowflake, an X- and a Super-X divertor. It is observed that alternative configurations can provide margin and resilience against large power fluctuations, but the…
Preprint PurchaseH.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…
Preprint Published