Showing 1 - 10 of 100 Journals Results
2021
UKAEA-CCFE-PR(21)04
M. Knolker T. Osborne E. Belli S. Henderson A. Kirk L. Kogan S. Saarelma P. B. Snyder
In preparation for the upcoming MAST-U campaign, pedestal stability of spherical tokamaks is revisited by investigating standard H-mode discharges on MAST. As a step beyond previous studies, both ion and electron profiles are used for obtaining equilibria and a diverse set of pedestals is evaluated. Stability analysis with the ELITE and CGYRO co…
Preprint2019
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 av…
Preprint2019
UKAEA-CCFE-PR(20)18
M Valovič P T Lang A Kirk W Suttrop A Bock P J Mc Carthy M Faitsch B Plöckl2 the ASDEX Upgrade team the EUROfusion MST1 team
It is demonstrated that tokamak plasma can be fuelled by pellets while simultaneously maintaining ELM suppression by external resonant magnetic perturbations (RMPs). Pellets are injected from vertical high field site and deposited at outer part of plasma cross section. Each pellet triggers benign MHD event followed by short lived ELM free phase. Th…
Preprint Published2018
UKAEA-RACE-PR(21)05
S. Kirk K. Keogh
The maintenance and decommissioning of nuclear reactors requires the rapid cutting and welding of thick-walled pipework, to which laser processing is highly suited. However, the large size and stand-off of current laser heads precludes their use in space constrained areas and incorporation into in-bore processing tools. To address this, novel minia…
Preprint Published2018
W. Suttrop A. Kirk V. Bobkov M. Cavedon M. Dunne R.M. McDermott H. Meyer R. Nazikian C. Paz-Soldan D.A. Ryan E. Viezzer M. Willensdorfer The ASDEX Upgrade MST1 Teams
Access conditions for full suppression of edge localised modes (ELMs) by magnetic perturbations (MP) in low density high confinement mode (H-mode) plasmas are studied in the ASDEX Upgrade tokamak. The main empirical requirements for full ELM suppression in our experiments are: 1. The poloidal spectrum of the MP must be aligned for best plasma respo…
Published2018
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 Bezier finite elements, that are aligned to the magnetic equilibrium of tokamak plasmas. To improve the applicability of these simulations, the grid-gene…
Preprint Purchase2019
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 roll…
Preprint Published2019
UKAEA-CCFE-PR(19)78
T. Farley N. R. Walkden F. Militello M. Sanna J. Young S. S. Silburn J. Harrison L. Kogan I. Lupelli S. S. Henderson A. Kirk J.W. Bradley
A new inversion technique is presented for the identification of plasma filaments in wide-angle visible camera data. Direct inversion of camera data onto a field aligned basis is a poorly conditioned problem which is overcome by breaking the analysis into a `psuedo-inversion’ step followed by a `point spread function correction’ step. Camera …
Preprint Published2019
UKAEA-CCFE-PR(19)39
Christopher Ham Andrew Kirk Stanislas Pamela Howard Wilson
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 Published2019
UKAEA-CCFE-PR(19)34