K. G. McClements R. J. Akers W.U. Boeglin M. Cecconello D. Keeling O.M. Jones A. Kirk I. Klimek R.V. Perez K. Shinohara K. Tani
The effects of resonant magnetic perturbations (RMPs) on the confinement of energetic (neutral beam) ions in the Mega Amp Spherical Tokamak (MAST) are assessed experimentally using measurements of neutrons, fusion protons and fast ion D _ (FIDA) light emission. In single null-diverted (SND) MAST pulses with relatively low plasma current (400 kA), t…
Preprint PublishedX. Yi A.E. Sand D.R. Mason M.A. Kirk S.G. Roberts K. Nordlund S.L. Dudarev
Using in-situ transmission electron microscopy, we have directly observed nano-scale defects formed in ultra-high purity tungsten by low-dose high energy self-ion irradiation at 30K. At cryogenic temperature lattice defects have reduced mobility, so these microscope observations over a window on the initial, primary damage caused by individual coll…
Preprint PublishedY. Liu R. Akers I.T. Chapman Y. Gribov G.Z. Hao G.T.A. Huijsmans A. Kirk A. Loarte S.D. Pinches M. Reinke D. Ryan Y. Sun Z.R. Wang
The linear and quasi-linear plasma response to the n = 3 and n = 4 (n is the toroidal mode number) resonant magnetic perturbation (RMP) fields, produced by the in-vessel edge localized mode control coils, is numerically studied for an ITER 15MA H-mode baseline Scenario. Both single fluid and fluid-kinetic hybrid models are used. The inclusion of dr…
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 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 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 PublishedC. J. Ham I. T. Chapman A. Kirk S. Saarelma
It is known that magnetic perturbations can mitigate edge localized modes (ELMs) in experiments, for example, MAST [Kirk et al., Nucl. Fusion 53, 043007 (2013)]. One hypothesis is that the magnetic perturbations cause a three dimensional corrugation of the plasma and this corrugated plasma has different stability properties to peeling-ballooning mo…
PublishedA.J. Thornton A. Kirk J.R. Harrison P. Cahyna I.T. Chapman E. Nardon The Mast Team
The high pressure gradients in the edge of a tokamak plasma can lead to the formation of explosive plasma instabilities known as edge localised modes (ELMs). The control of ELMs is an important requirement for the next generation of fusion devices such as ITER. Experiments performed on the Mega Amp Spherical Tokamak (MAST) at Culham have shown that…
PublishedYueqiang Liu A. Kirk A.J. Thornton Mast Team
Optimal correction of the intrinsic error field (EF) by the correction coils in MAST is numerically studied, based on linear, full MHD plasma response computed in full toroidal geometry. Various optimisation criteria are proposed, and the results are compared with empirical optima from representative error field correction (EFC) experiments. The tw…
PublishedA. Kirk Yueqiang Liu R. Martin G. Cunningham D. Howell The Mast Team
The misalignment of field coils in tokamaks can lead to toroidal asymmetries in the magnetic field, which are known as intrinsic error fields. These error fields often lead to the formation of locked modes in the plasma, which limit the lowest density that is achievable. The intrinsic error fields on MAST have been determined by the direct measurem…
Published