F. Militello P. Tamain W. Fundamenski A. Kirk V. Naulin A.H. Nielsen The Mast Team
Numerical simulations of interchange turbulence in the Scrape-Off Layer are performed in a regime relevant for a specific L-mode MAST (Mega Ampere Spherical Tokamak) discharge. Such a discharge was diagnosed with a reciprocating arm equipped with a Gundestrup probe. A detailed comparison of the average and statistical properties of the simulated an…
PublishedA.Kirk I.T. Chapman Yueqiang Liu P. Cahyna P. Denner G. Fishpool C.J. Ham J.R. Harrison Yunfeng Liang E. Nardon S. Saarelma R. Scannell A.J. Thornton The Mast Team
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 frequency increases by up to a factor of eight with a similar reduction in ELM energy loss. A threshold current for ELM mitigation is observed above which the ELM freque…
PublishedG. Fishpool J. Canik G. Cunningham J. Harrison I. Katramados A. Kirk M. Kovari H. Meyer R. Scannell The Mast-Upgrade Team
A potentially important feature in a divertor design for a high-power tokamak is an extended and expanded divertor leg. The upgrade to MAST will allow a wide range of such divertor leg geometries to be produced, and hence will allow the roles of greatly increased connection length and flux expansion to be experimentally tested. This will include te…
PublishedS. Elmore S. Y. Allan A. Kirk A. J. Thornton J. R. Harrison P. Tamain M. Kocan J. W. Bradley The Mast Team
Knowledge of the ion temperature (Ti) is of key importance for determining heat fluxes to the divertor and plasma facing components, however data regarding this is limited compared to electron temperature (Te) data. Ti measurements at the divertor target, between edge-localised modes (inter-ELM) H-mode, have been made using a novel retarding field …
PublishedA.J. Thornton A. Kirk I.T. Chapman J.R. Harrison The Mast Team
Edge localised modes (ELMs) are a concern for future devices as they can limit the operational lifetime of the divertor. The mitigation of ELMs can be performed by the application of resonant magnetic perturbations (RMPs) which act to degrade the pressure gradient in the edge of the plasma. Investigations of the effect of RMPs on MAST have been per…
PublishedA.J. Thornton K.J. Gibson J.R. Harrison M. Lehnen R. Martin A. Kirk The Mast Team
Disruptions are of significant concern to future devices, due to the large amount of energy released during the rapid quenching of the plasma. Disruption mitigation has been performed on MAST, to study the effect on heat loads and disruption time scales in a spherical tokamak. Massive gas injection is performed using a disruption mitigation valve c…
PublishedA. Kirk I.T. Chapman J. Harrison Yueqiang Liu E. Nardon S. Saarelma R. Scannell A.J. Thornton The Mast Team
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 increase in Edge Localized Mode (ELM) frequency and reduction in plasma energy loss associated with type-I ELMs. A threshold current for ELM mitigation is observed above wh…
PublishedM Valovic G Cunningham L Garzotti C Gurl A Kirk G Naylor A Patel R Scannell The Mast Team
Shallow fuelling pellets are injected from the high field side into plasmas in which ELMs have been mitigated using external magnetic perturbation coils. The data are compared with ideal assumptions in the ITER fuelling model, namely that mitigated ELMs are not affected by fuelling pellets. Firstly it is shown that during the pellet evaporation an …
PublishedI.T. Chapman A. Kirk S. Saarelma J.R. Harrison R. Scannell The Mast Team
The application of resonant magnetic perturbations with toroidal mode number n = 4 or n = 6 is observed to result in a significant increase in ELM frequency, despite a reduction in the edge pressure gradient. A picture for how type-I ELMs are mitigated, or destabilised, when magnetic perturbations are applied is proposed. Despite the magnetic pertu…
PublishedI.T. Chapman W.A. Cooper A. Kirk C.J. Ham J.R. Harrison A. Patel S.D. Pinches R. Scannell A.J. Thornton The Mast Team
The distortion of the plasma boundary when three-dimensional resonant magnetic perturbations are applied has been measured in MAST H-mode plasmas. When the n = 3 resonant magnetic perturbations are applied to control edge localised modes, the plasma experiences a strong toroidal corrugation. The displacement of the plasma boundary is measured at va…
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