Showing 1 - 10 of 48 Journals Results
2021
UKAEA-CCFE-PR(21)19
S. H. Ward R. Akers A. Jacobsen P. Ollus S. D. Pinches E. Tholerus R. G. L. Vann M. A. Van Zeeland
A novel high-performance computing algorithm, developed in response to the next generation of computational challenges associated with burning plasma regimes in ITER-scale tokamak devices, has been tested and is described herein. LOCUST-GPU 2 The Lorentz-Orbit Code for Use in Stellarators and Tokamaks (LOCUST) is designed for computationally s…
Preprint2018
UKAEA-CCFE-PR(19)05
M. Fitzgerald J. Buchanan R.J. Akers B.N. Breizman S.E. Sharapov
HALO (HAgis LOcust) solves the initial value Vlasov-Maxwell problem perturbatively for application to certain nonlinear wave-particle problems in tokamak plasmas. It uses the same basic approach as the HAGIS code (Pinches et al., 1998) for wave evolution but is built on the LOCUST-GPU full-orbit code (Akers et al., 2012) for the solution of the Ham…
Preprint Published2018
UKAEA-CCFE-PR(18)28
M. Fitzgerald J. Buchanan S. E. Sharapov V. G. Kiptily M. Sertoli G. Szepesi J. Boom R. Akers D. King JET contributors
Fishbones are ubiquitous in high-performance JET plasmas and are typically considered to be unimportant for scenario design. However, during recent high-performance hybrid experiments, sporadic and explosive fishbones have been observed which correlate with a reduction in performance and main chamber hotspots. Clear evidence has been obtained of fu…
Preprint Published2018
UKAEA-CCFE-PR(18)4
K. G. McClements K. Tani R. J. Akers Y. Q. Liu K. Shinohara H. Tsutsui S. Tsuji-Iio
The application of non-axisymmetric resonant magnetic perturbations (RMPs) to low current plasmas in the Mega Amp Spherical Tokamak (MAST) was found to be correlated with substantial drops in neutron production, suggesting a significant degradation of fast ion confinement. The effects of such perturbations on fast ions in MAST have been modelled us…
Preprint Published2016
CCFE-PR(16)40
K. Tani K. Shinohara T. Oikawa H. Tsutsui K.G. McClements R.J. Akers Y.Q. Liu M. Suzuki S. Ide Y. Kusama S. Tsuji-Iio
A non-steady-state orbit-following Monte-Carlo code has been developed. As part of the verification and validation of the code, calculations of time dependent neutron rates have been made for a specific shot in the Mega Amp Spherical Tokamak (MAST) using three-dimensional fields representing vacuum resonant magnetic perturbations (RMPs) and toroida…
Preprint Published2016
CCFE-PR(16)34
L.M. Evans J.D. Arregui-Mena P. M. Mummery R. Akers E. Surrey A. Shterenlikht M. Broggi L. Margetts
The extreme environments found within the nuclear sector impose large safety factors on modelling analyses to ensure components operate in their desired manner. Improving analysis accuracy has clear value of increasing the design space that could lead to greater efficiency and reliability. Novel materials for new reactor designs often exhibit non-…
Preprint Published2015
CCFE-PR(15)50
O.M. Jones M. Cecconello K.G. McClements I. Klimek R.J. Akers W.U. Boeglin D.L. Keeling A.J. Meakins R.V. Perez S.E. Sharapov M. Turnyanskiy The MAST team
The results of a comprehensive investigation into the effects of toroidicity- induced Alfven eigenmodes (TAE) and energetic particle modes on the NBI-generated fast-ion population in MAST plasmas are reported. Fast-ion redistribution due to frequency-chirping TAE in the range 50 kHz to 100 kHz, and frequency-chirping energetic particle modes known …
Preprint Published2015
CCFE-PR(15)47
K. G. McClements R. J. Akers W.U. Boeglin M. Cecconello D. Keeling O.M. Jones A. Kirk I. Klimek R.V. Perez K. Shinohara K. Tani
The effects of resonant magnetic perturbations (RMPs) on the confinement of energetic (neutral beam) ions in the Mega Amp Spherical Tokamak (MAST) are assessed experimentally using measurements of neutrons, fusion protons and fast ion D _ (FIDA) light emission. In single null-diverted (SND) MAST pulses with relatively low plasma current (400 kA), t…
Preprint Published2015
CCFE-PR(15)114
Y. Liu R. Akers I.T. Chapman Y. Gribov G.Z. Hao G.T.A. Huijsmans A. Kirk A. Loarte S.D. Pinches M. Reinke D. Ryan Y. Sun Z.R. Wang
The linear and quasi-linear plasma response to the n = 3 and n = 4 (n is the toroidal mode number) resonant magnetic perturbation (RMP) fields, produced by the in-vessel edge localized mode control coils, is numerically studied for an ITER 15MA H-mode baseline Scenario. Both single fluid and fluid-kinetic hybrid models are used. The inclusion of dr…
Preprint Published2015
CCFE-PR(17)40