K. Heinola A. Widdowson J. Likonen E. Alves A. Baron-Wiechec N. Barradas S. Brezinsek N. Catarino P. Coad S. Koivuranta G.F. Matthews M. Mayer P. Petersson JET-EFDA Contributors
Selected Ion Beam Analysis techniques applicable for detecting deuterium and heavier impurities have been used in the post-mortem analyses of tiles removed after the first JET ITER-Like Wall (JET-ILW) campaign. Over half of the retained fuel was measured in the divertor region. The highest figures for fuel retention were obtained from regions with …
Preprint PublishedS. Elmore S.Y. Allan G. Fishpool A. Kirk M. Kocan P. Tamain A.J. Thornton The MAST Team
Edge-localised modes (ELMs) can carry significant fractions of their energy as far as main chamber plasma-facing components in divertor tokamaks. Since in future devices (e.g. ITER, DEMO) these energies could cause issues for material lifetime and impurity production, the energy and temperature of ions in ELMs needs to be investigated. In MAST, nov…
Preprint PublishedJ. Beal A. Widdowson K. Heinola A. Baron-Wiechec K. J. Gibson J. P. Coad E. Alves B. Lipschultz A. Kirschner G. F. Matthews S. Brezinsek JET-EFDA Contributors
Rotating collectors are used in JET to provide time-resolved measurements of erosion and redeposition of vessel materials. The silicon collecting disks rotate behind an aperture, driven by pulsing of the toroidal magnetic field, with the deposits analysed ex-situ by Nuclear Reaction Analysis. The angular dependence of deposition is mapped to discha…
Preprint PublishedJ.R. Harrison G.M. Fishpool B.D. Dudson
Measurements of intensity fluctuation of light emission within the divertor volume of MAST provide strong evidence for the existence of filamentary structures within the private flux region (PFR). These filaments are observed in L-mode and H-mode confinement regimes. Correlation analysis of the camera data supports the hypothesis that the filaments…
Preprint PublishedT. Eade D. Stonell A. Turner
As nuclear fusion progresses towards a sustainable energy source and the power of tokamak devices increases, a greater understanding of the radiation fields will be required. As well as on-load radiation fields, off-load or shutdown radiation field are an important consideration for the safety and economic viability of a commercial fusion reactor. …
Preprint PublishedT.S. Lee I. Jenkins E. Surrey D.P. Hampshire
The potential for reducing the Cost of Electricity (CoE) by using High Temperature Superconductors (HTS)in the Toroidal Field (TF) coils of a fusion tokamak power plant has been investigated using a new HTS module in the PROCESS systems code. We report the CoE and the design of HTS tokamaks that have been optimised by minimising the major radius of…
Preprint PublishedA.J. Thornton A. Kirk P. Cahyna I.T. Chapman G. Fishpool J.R. Harrison Y.Q. Liu L. Kripner M. Peterka The MAST Team
The application of resonant magnetic perturbations (RMPs) produces splitting of the divertor strike point due to the interaction of the RMP field and the plasma field. The application of a rotating RMP field causes the strike point splitting to rotate, distributing the particle and heat flux evenly over the divertor. The RMP coils in MAST have been…
Preprint PublishedV.F. Shevchenko Y.F. Baranov T. Bigelow J.B. Caughman S. Diem C. Dukes P. Finburg J. Hawes C. Gurl J.Griffiths J. Mailloux M. Peng A.N. Saveliev Y. TakaHe H. Tanaka G. Taylor
Start-up technique reported here relies on a double mode conversion (MC) for electron Bernstein wave (EBW) excitation. It consists of MC of the ordinary (0) mode, entering the plasma from the low field side of the tokamak, into the extraordinary (X) mode at a mirror-polarizer located at the high field side. The X mode propagates back to the plasma,…
Preprint PublishedS. J. Freethy K. G. McClements S. C. Chapman R. O. Dendy W. N. Lai S. J. P. Pamela V. F. Shevchenko R. G. L. Vann
Recent measurements of microwave and x-ray emission during edge localized mode (ELM) activity in tokamak plasmas provide a fresh perspective on ELM physics. It is evident that electron kinetics, which are not incorporated in standard (fluid) models for the instability that drives ELMs, play a key role in the new observations. These effects should b…
Preprint PublishedN.R. Walkden J. Adamek S. Allan B. D. Dudson S. Elmore G. Fishpool J. Harrison A. Kirk M. Komm
The ball pen probe (BPP) technique is used successfully to make profile measurements of plasma potential, electron temperature, and radial electric field on the Mega Amp Spherical Tokamak. The potential profile measured by the BPP is shown to significantly differ from the floating potential both in polarity and profile shape. By combining the BPP p…
Preprint Published