B. Hnat S. Gadgil A. Kirk F. Militello N. Walkden The MAST Team
Reciprocating Mach probe data is used to estimate the radial wave number of oscillatory zonal flows in Ohmic MAST plasma. An intermittent 10kHz mode is detected in the wavelet decomposition and windowed spectra of plasma potential fluctuations of the MAST tokamak edge plasma. Previously, this mode has been identified as a Geodesic Acoustic Mode (GA…
Preprint PublishedL. Yueqiang A. Kirk L. Li Y. In R. Nazikian Y. Sun W. Suttrop B. Lyons D. Ryan S. Wang X. Yang L. Zhou EUROfusion MST1 team
Extensive modelling efforts of the plasma response to the resonant magnetic perturbation fields, utilized for controlling the edge localized mode (ELM), help to identify the edge-peeling response as a key factor, which correlates to the observed ELM mitigation in several tokamak devices, including MAST, ASDEX Upgrade, EAST, and HL-2A. The recently …
PublishedY. Liu C.J. Ham A. Kirk L. Li A. Loarte D.A. Ryan Y. Sun W. Suttrop X. Yang L. Zhou
Resonant magnetic perturbations (RMP) have extensively been demonstrated as a plausible technique for mitigating or suppressing large edge localized modes (ELMs). Associated with this is a substantial amount of theory and modelling efforts during recent years. Various models describing the plasma response to the RMP fields have been proposed in the…
Preprint PublishedT. R. Barrett G. Ellwood G. Pérez M. Kovari M. Fursdon F. Domptail S. Kirk S.C. McIntosh S. Roberts S. Zheng L.V. Boccaccini J-H. You C. Bachmann J. Reiser M. Rieth E. Visca G. Mazzone F. Arbeiter P.K. Domalapally
The European DEMO power reactor is currently under conceptual design within the EUROfusion Consortium. One of the most critical activities is the engineering of the plasma-facing components (PFCs) covering the plasma chamber wall, which must operate reliably in an extreme environment of neutron irradiation and surface heat and particle flux, while …
Preprint PublishedS. Kirk M. Porton G. Perez Z. Vizvary N. Luzginova G. Eaton S. Banetta T. Cicero
The detachment of a beryllium tile from the ITER Normal Heat Flux (NHF) First Wall (FW) panels would result in an unacceptable degradation of panel performance. Such detachment has previously been observed under High Heat flux (HHF) testing of NHF FW prototypes, with initiation of de-bonding at tile edges and subsequent delamination occurring betwe…
PreprintG. Pérez M. Porton S. Kirk Z. Vizvary G. Eaton
The European ITER First Wall panel design relies on a HIP based manufacturing sequence. However, failures of the bond to the beryllium tile might occur during the fabrication and under high heat flux qualification. A dedicated project has been stablished between UKAEA/CCFE and F4E aiming to identify suitable repair techniques. One of the most prom…
PreprintA. 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 PublishedJ.C. Hillesheim D. Dickinson C.M. Roach S. Saarelma R. Scannell A. Kirk N.A. Crocker W.A. Peebles H. Meyer The MAST Team
Measurements of local density and magnetic field fluctuations near the pedestal top, conditionally-averaged over the ELM cycle, have been made in MAST. A Doppler backscattering (DBS) system installed at MAST was used to measure intermediate-k (k ? _i _ 3 - 4) density fluctuations at the top of the pedestal. A novel diagnostic technique combining DB…
Preprint PublishedC.J. Ham R.G.J. Cramp S. Gibson S.A. Lazerson I.T. Chapman A. Kirk
The magnetic perturbations produced by the resonant magnetic perturbation (RMP) coils will be rotated in ITER so that the spiral patterns due to strike point splitting which are locked to the RMP also rotate. This is to ensure even power deposition on the divertor plates. VMEC equilibria are calculated for different phases of the RMP rotation. It i…
Preprint PublishedM. 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 Published