J.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 PublishedJ.C. Hillesheim N. A. Crocker W.A. Peebles H. Meyer A. Meakins A.R. Field D. Dunai M. Carr N. Hawkes The MAST Team
The high-k (7 . k??i . 11) wavenumber spectrum of density fluctuations has been measured for the first time in MAST [B. Lloyd et al, Nucl. Fusion 43, 1665 (2003)]. This was accomplished with the first implementation of Doppler backscattering (DBS) for core measurements in a spherical tokamak. DBS has become a well-established and versatile diagnost…
Preprint PublishedJ.C. Hillesheim F.I. Parra M. Barnes N.A. Crocker H. Meyer W.A. Peebles R. Scannell A. Thornton The MAST Team
Tokamak plasmas rotate even without external injection of momentum. A Doppler backscattering system installed at MAST has allowed this intrinsic rotation to be studied in Ohmic L-mode and Hmode plasmas, including the first observation of intrinsic rotation reversals in a spherical tokamak. Experimental results are compared to a novel 1D model, whic…
Preprint PublishedJ. C. Hillesheim E. Delabie H. Meyer C. F. Maggi L. Meneses E. Poli JET Contributors
High spatial resolution Doppler backscattering measurements in JET have enabled new insights into the development of the edge . We observe fine-scale spatial structures in the edge well with a wave number kr ? i ˜ 0.4–0.8, consistent with stationary zonal flows, the characteristics of which vary with density. The zonal flow amplitude and wavelen…
Preprint PublishedS. A. Silburn J. R. Harrison J. Howard K. J. Gibson H. Meyer C. A. Michael R. M. Sharples
A new coherence imaging Doppler spectroscopy diagnostic has been deployed on the UK’s Mega Amp Spherical Tokamak for scrape-off-layer and divertor impurity flow measurements. The system has successfully obtained 2D images of C III, C II, and He II line-of-sight flows, in both the lower divertor and main scrape-off-layer. Flow imaging has been obt…
PublishedJ.C. Hillesheim F.I. Parra,M. Barnes N.A. Crocker H. Meyer W.A. Peebles R. Scannell A. Thornton The Mast Team
Tokamak plasmas rotate even without any external injection of momentum. A Doppler backscattering system installed at MAST has allowed this intrinsic rotation to be studied in Ohmic L-mode and H-mode plasmas, including the first observation of intrinsic rotation reversals in a spherical tokamak. Experimental results are compared to a novel 1D model,…
PublishedH. Meyer I.G. Abel R.J. Akers A. Allan S.Y. Allan L.C. Appel O. Asunta M. Barnes N.C. Barratt Et Al
New diagnostic, modelling and plant capability on the Mega Ampere Spherical Tokamak (MAST) have delivered important results in key areas for ITER/DEMO and the upcoming MAST Upgrade, a step towards future ST devices on the path to fusion currently under procurement. Micro-stability analysis of the pedestal highlights the potential roles of micro-tea…
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…
PublishedA. Kirk Yueqiang Liu E. Nardon P. Tamain P. Cahyna I. Chapman P. Denner H. Meyer S. Mordijck D. Temple The Mast Team
Experiments have been performed on MAST using internal (n=3) resonant magnetic perturbation coils. The application of the RMPs to L-mode discharges has shown a clear density pump out when the field line pitch angle at the low field side of the plasma is sufficiently well aligned with the applied field. The application of the RMPs before the L-H tra…
Published