149 citations · 1.3k across the 22 of their papers we have counts for
22 papers
The JET hybrid H-mode scenario from a pedestal turbulence perspective
L. A. Leppin, T. Görler, L. Frassinetti +4
Turbulent transport is a decisive factor in determining the pedestal structure of H-modes. Here, we present the first comprehensive characterization of gyrokinetic turbulent transp…
Flat-top plasma operational space of the STEP power plant
E. Tholerus, F. J. Casson, S. P. Marsden +16
STEP is a spherical tokamak prototype power plant that is being designed to demonstrate net electric power. The design phase involves the exploitation of plasma models to optimise…
Flexible, integrated modeling of tokamak stability, transport, equilibrium, and pedestal physics
B. C. Lyons, J. McClenaghan, T. Slendebroek +15
The STEP (Stability, Transport, Equilibrium, and Pedestal) integrated-modeling tool has been developed in OMFIT to predict stable, tokamak equilibria self-consistently with core-tr…
Three-Dimensional Inhomogeneity of Electron-Temperature-Gradient Turbulence in the Edge of Tokamak Plasmas
J. F. Parisi, F. I. Parra, C. M. Roach +15
Nonlinear multiscale gyrokinetic simulations of a Joint European Torus edge pedestal are used to show that electron-temperature-gradient (ETG) turbulence has a rich three-dimension…
Microtearing modes as the source of magnetic fluctuations in the JET pedestal
D. R. Hatch, M. Kotschenreuther, S. M. Mahajan +15
We report on a detailed study of magnetic fluctuations in the JET pedestal, employing basic theoretical considerations, gyrokinetic simulations, and experimental fluctuation data,…
Gyrokinetic analysis and simulation of pedestals, to identify the culprits for energy losses using fingerprints
M. Kotschenreuther, X. Liu, D. R. Hatch +14
Fusion performance in tokamaks hinges critically on the efficacy of the Edge Transport Barrier (ETB) at suppressing energy losses. The new concept of fingerprints is introduced to…
Direct Gyrokinetic Comparison of Pedestal Transport in JET with Carbon and ITER-Like Walls
D. R. Hatch, M. Kotschenreuther, S. M. Mahajan +8
This paper compares the gyrokinetic instabilities and transport in two representative JET pedestals, one (pulse 78697) from the JET configuration with a carbon wall (C) and another…
Overview of recent physics results from MAST
A Kirk, J Adamek, RJ Akers +160
New results from MAST are presented that focus on validating models in order to extrapolate to future devices. Measurements during start-up experiments have shown how the bulk ion…
Improved Confinement in JET High {beta} Plasmas with an ITER-Like Wall
C. D. Challis, J. Garcia, M. Beurskens +18
The replacement of the JET carbon wall (C-wall) by a Be/W ITER-like wall (ILW) has affected the plasma energy confinement. To investigate this, experiments have been performed with…
Effect of resonant magnetic perturbations on low collisionality discharges in MAST and a comparison with ASDEX Upgrade
A. Kirk, W. Suttrop, Yueqiang Liu +19
Sustained ELM mitigation has been achieved on MAST and AUG using RMPs with a range of toroidal mode numbers over a wide region of low to medium collisionality discharges. The ELM e…
Contrasting H-mode behaviour with deuterium fuelling and nitrogen seeding in the all-carbon and metallic versions of JET
G. P. Maddison, C. Giroud, B. Alper +48
The former all-carbon wall on JET has been replaced with beryllium in the main torus and tungsten in the divertor to mimic the surface materials envisaged for ITER. Comparisons are…
Current understanding of the processes underlying the triggering of and energy loss associated with type I ELMs
A. Kirk, D. Dunai, M. Dunne +7
The type I ELMy H-mode is the baseline operating scenario for ITER. While it is known that the type I ELM ultimately results from the peeling-ballooning instability, there is growi…
Modelling of three dimensional equilibrium and stability of MAST plasmas with magnetic perturbations using VMEC and COBRA
C J Ham, I T Chapman, A Kirk +1
It is known that magnetic perturbations can mitigate edge localized modes (ELMs) in experiments, for example MAST (Kirk et al 2013 Nucl. Fusion 53 043007). One hypothesis is that t…
Comparison of BES measurements of ion-scale turbulence with direct, gyrokinetic simulations of MAST L-mode plasmas
A R Field, D Dunai, Y-c Ghim +7
Observations of ion-scale (k_y*rho_i <= 1) density turbulence of relative amplitude dn_e/n_e <= 0.2% are available on the Mega Amp Spherical Tokamak (MAST) using a 2D (8 radial x 4…
Understanding ELM mitigation by resonant magnetic perturbations on MAST
A. Kirk, I. T. Chapman, Yueqiang Liu +11
Sustained ELM mitigation has been achieved using RMPs with a toroidal mode number of n=4 and n=6 in lower single null and with n=3 in connected double null plasmas on MAST. The ELM…
Towards understanding edge localised mode mitigation by resonant magnetic perturbations in MAST
I. T. Chapman, A. Kirk, C. J. Ham +10
Type-I Edge Localised Modes (ELMs) have been mitigated in MAST through the application of n = 3, 4 and 6 resonant magnetic perturbations (RMPs). For each toroidal mode number of th…
Effect of resonant magnetic perturbations with toroidal mode numbers of 4 and 6 on ELMs in single null H-mode plasmas in MAST
A. Kirk, I. T. Chapman, J. Harrison +6
The application of resonant magnetic perturbations (RMPs) with a toroidal mode number of n=4 or n=6 to lower single null plasmas in the MAST tokamak produces up to a factor of 5 in…
MHD and Gyro-kinetic Stability of JET Pedestals
S. Saarelma, M. N. A. Beurskens, D. Dickinson +4
The pedestal profile measurements in high triangularity JET plasmas show that with low fuelling the pedestal width decreases during the ELM cycle and with high fuelling it stays co…
Microtearing modes at the top of the pedestal
D. Dickinson, C. M. Roach, S. Saarelma +3
Microtearing modes (MTMs) are unstable in the shallow gradient region just inside the top of the pedestal in the spherical tokamak experiment MAST, and may play an important role i…
Kinetic instabilities that limit β in the edge of a tokamak plasma: a picture of an H-mode pedestal
D. Dickinson, C. M. Roach, S. Saarelma +3
Plasma equilibria reconstructed from the Mega-Amp Spherical Tokamak (MAST) have sufficient resolution to capture plasma evolution during the short period between edge-localized mod…
Towards the construction of a model to describe the inter-ELM evolution of the pedestal on MAST
D. Dickinson, S. Saarelma, R. Scannell +3
Pedestal profiles that span the ELM cycle have been obtained and used to test the idea that the pedestal pressure gradient in MAST is limited by the onset of Kinetic Ballooning Mod…
Observation of confined current ribbon in JET plasmas
E. R. Solano, P. J. Lomas, B. Alper +29
we report the identification of a localised current structure inside the JET plasma. It is a field aligned closed helical ribbon, carrying current in the same direction as the back…