H. Tanabe T. Yamada T. Watanabe K. Gi M. Inomoto R. Imazawa M. Gryaznevich C. Michael B. Crowley N. J. Conway R. Scannell J. Harrison I. Fitzgerald A. Meakins N. Hawkes K. G. McClements T. O'Gorman C. Z. Cheng Y. Ono The MAST team
In the last three years, magnetic reconnection research in the MAST spherical tokamak achieved major progress by use of new 32 chord ion Doppler tomography, 130 channel YAG and 300 channel Ruby Thomson scattering diagnostics. In addition to the previously achieved high power plasma heating during merging, detailed full temperature profile measureme…
Preprint PublishedP.M.S. Buller I. Pusztai S.L. Newton J.T. Omotani
In tokamak transport barriers, the radial scale of profile variations can be comparable to a typical ion orbit width, which makes the coupling of the distribution function across flux surfaces important in the collisional dynamics. We use the radially global steady-state neoclassical f code Perfect to calculate poloidal and toroidal flows, and radi…
Preprint PublishedB. Layden Z. S. Qu M. Fitzgerald M. J. Hole
A number of tools have recently been developed to study equilibrium and stability in tokamaks with pressure anisotropy. Here we apply these tools to a Mega Ampere Spherical Tokamak (MAST) discharge to calculate equilibrium, Alfven continua and eigenmodes, through to linear growth and nonlinear saturation of a toroidal Alfven eigenmode (TAE); this i…
Preprint PublishedP. Helander F.I. Parra S.L. Newton
The bootstrap current and flow velocity of a low-collisionality stellarator plasma are calculated. As far as possible, the analysis is carried out in a uniform way across all low-collisionality regimes in general stellarator geometry, assuming only that the confinement is good enough that the plasma is approximately in local thermodynamic equilibri…
Preprint PublishedW. Guttenfelder A.R. Field I. Lupelli T. Tala S.M. Kaye Y. Ren W.M. Solomon
Non-axisymmetric magnetic fields are used to perturbatively probe momentum transport physics in MAST L-mode plasmas. The low beta L-mode target was chosen to complement previous experiments conducted in high beta NSTX H-mode plasmas (ßN=3.5-4.6) where an inward momentum pinch was measured. In those cases quasi-linear gyrokinetic simulations of uns…
Preprint PublishedG. J. Colyer A. A. Schekochihin F. I. Parra C. M. Roach M. A. Barnes Y. C. Ghim W. Dorland
In electrostatic simulations of MAST plasma at electron-gyroradius scales, using the local flux-tube gyrokinetic code GS2 with adiabatic ions, we find that the longtime saturated electron heat flux (the level most relevant to energy transport) decreases as the electron collisionality decreases. At early simulation times, the heat flux quasisatura…
Preprint PublishedM.R. Gilbert J.-Ch. Sublet
The neutrons generated in fusion plasmas interact with materials via nuclear reactions. The resulting transmutations and atomic displacements have life-limiting consequences for fusion reactor components. A detailed understanding of the production, evolution and material consequences of the damage created by cascades of atomic displacements require…
Preprint PublishedZ.S. Qu M.J. Hole M. Fitzgerald
In this paper we have developed a fluid model to study the radial mode structure of the reactive energetic geodesic acoustic modes (reactive EGAMs), a branch of GAM that becomes unstable in the presence of a cold fast ion beam. We have solved the resulting dispersion relationship, a second order ODE, both analytically in restricted cases and numeri…
Preprint PublishedG. 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…
PreprintB.P Wynne M.J. Gorley P.F. Zheng A.J. Cackett M. Porton E. Surrey
The microstructure and thermal stability of V-4Cr-4Ti-1.8Y-0.4Ti3SiC2 alloy, fabricated by 60 hr mechanical milling of blended powders followed by spark plasma sintering (SPS) and hot isostatic pressing, has been investigated. Analysis was undertaken using orientation image maps obtained from the electron backscattering and transmission Kikuchi dif…
Preprint Purchase