Showing 1 - 10 of 36 Journals Results
2020
UKAEA-CCFE-PR(20)139
J.M. Gao L.Z. Cai X.L. Zou T. Eich C.Z Cao L.W. Yan W.L. Zhong A.J. Thornton J.Adamek X.Q. Ji M. Jiang L. Liu J. Lu G.L. Xiao Z.H. Huang N. Wu
The HL-2A tokamak has a very closed divertor geometry, and a new infrared camera has been installed for high resolution studies of edge-localized mode (ELM) heat load onto the outer divertor targets. The characteristics of power deposition patterns on the lower outer divertor target plates during ELMs are systematically analyzed with the infrared t…
Preprint2020
UKAEA-CCFE-PR(20)129
S.Pamela G.Huijsmans A.J.Thornton A.Kirk S.F.Smith M.Hoelzl T.Eich JET Contributors the MAST Team the JOREK Team
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 B'{e}zier finite elements, that are aligned to the magnetic equilibrium of tokamak plasmas. To improve the applicability of these simulations, the grid-g…
Preprint Purchase2020
UKAEA-CCFE-PR(20)67
S.A. Sabbagh J.W. Berkery Y.S. Park J.H. Ahn Y. Jiang J.D. Riquezes J.G. Bak R.E. Bell M.D. Boyer L. Delgado-Aparicio A.H. Glasser J. Hollocombe J. Kim A. Kirk J. Ko W. Ko L. Kogan B.P. LeBlanc J.H. Lee C.E. Myers L. Terzolo A. Thornton S.W. Yoon
Disruption prediction and avoidance is a critical need for next-step tokamaks such as ITER. The Disruption Event Characterization and Forecasting Code (DECAF) is used to fully automate analysis of tokamak data to determine chains of events that lead to disruptions and to forecast their evolution allowing sufficient time for mitigation or full avoid…
Preprint2020
UKAEA-CCFE-PR(20)07
S.F. Smith S.J.P. Pamela A. Fil M. Hoelzl G.T.A. Huijsmans A. Kirk D.Moulton O. Myatra A.J. Thornton H.R. Wilson
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 ro…
Preprint Purchase2019
UKAEA-CCFE-PR(19)34
D.J. Battaglia S.P. Gerhardt A. Kirk L. Kogan J.E. Menard D. Mueller A.J. Thornton
Reduced models coupled to time-dependent axisymmetric vacuum field calculations are used to develop the prefill and feed-forward coil current targets required for reliable direct induction (DI) startup on the new MA-class spherical tokamaks, MAST-U and NSTX-U. The calculations are constrained by operational limits unique to each device, such as the…
Preprint Published2017
CCFE-PR(17)65
N. R. Walkden J. Harrison S. A. Silburn T. Farley S.S. Henderson A. Kirk F. Militello A.Thornton the MAST Team
Using high speed imaging of the divertor volume, the region close to the X-point in MAST is shown to be quiescent. This is confirmed by three different analysis techniques and the quiescent X-point region (QXR) spans from the separatrix to the N = 1.02 flux surface. Local reductions to the atomic density and effects associated with the camera vie…
Preprint Published2016
CCFE-PR(17)18
A. Kirk A.J. Thornton J.R. Harrison F. Militello N.R. Walkden The MAST Team The EUROfusion MST1 Team
Clear filamentary structures are observed at the edge of tokamak plasmas. These filaments are ejected out radially and carry plasma in the far Scrape Off Layer (SOL) region, where they are responsible for producing most of the transport. A study has been performed of the characteristics of the filaments observed in L-mode plasma on MAST, using visi…
Preprint Published2016
CCFE-PR(16)09
M. Valovič P.T. Lang A. Kirk W. Suttrop M. Cavedon G. Cseh M. Dunne L.R. Fischer L. Garzotti L. Guimarais G. Kocsis A. Mlynek B. Plőckl R. Scannell T. Szepesi G. Tardini A. Thornton E. Viezzer E. Wolfrum The ASDEX Upgrade team The EUROfusion MST1 team
The complete refuelling of the plasma density loss (pump-out) caused by mitigation of Edge Localised Modes (ELMs) is demonstrated on the ASDEX Upgrade tokamak. The plasma is refuelled by injection of frozen deuterium pellets and ELMs are mitigated by external resonant magnetic perturbations (RMPs). In this experiment relevant dimensionless paramete…
Preprint Published2016
CCFE-PR(16)30
S. Elmore S.Y. Allan G. Fishpool A. Kirk A.J. Thornton N.R. Walkden J.R. Harrison The MAST Team
In future nuclear fusion reactors high heat load events, such as edge-localised modes (ELMs), can potentially damage divertor materials and release impurities into the main plasma, limiting plasma performance. The most difficult to handle are type I ELMs since they carry the largest fraction of energy from the plasma and therefore deposit the large…
Preprint Published2015
CCFE-PR(15)53