S. 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 PublishedJ. R. Harrison G. M. Fishpool A. J. Thornton N. R. Walkden MAST team
The transport of particles via intermittent filamentary structures in the private flux region (PFR) of plasmas in the MAST tokamak has been investigated using a fast framing camera recording visible light emission from the volume of the lower divertor, as well as Langmuir probes and IR thermography monitoring particle and power fluxes to plasma-fac…
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…
PublishedH.J.C. Oliver S.E. Sharapov R. Akers I. Klimek M. Cecconello The Mast Team
Compressional Alfven and ion-ion hybrid waves excited by energetic beam ions are studied in plasmas with two ion species. In our experiment, a hydrogendeuterium (H-D) plasma is used to produce instabilities similar to those likely to be present in the burning deuterium-tritium plasmas of future tokamaks. Modes are suppressed in the deuterium cyclot…
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…
PublishedI.T. Chapman J.T. Holgate N. Ben Ayed G. Cunningham C.J. Ham J.R. Harrison A. Kirk G. Mcardle A. Patel R. Scannell The Mast Team
When resonant magnetic perturbations are applied in MAST, the plasma edge boundary experiences a three dimensional distortion, which can be a few percent of the minor radius in amplitude, in good agreement with ideal 3d equilibrium modelling. This displacement occurs in plasmas both with radial position feedback control applied, and without feedbac…
PublishedA.J. Thornton A. Kirk The Mast Team
The power load to the divertor surfaces is a key concern for future devices such as ITER, due to the thermal limits on the material surface. One factor that characterises the heat flux to the divertor is the fall off length in the SOL, which recent empirical scalings have shown could be as small as 1 mm. These predictions are based on a multi-machi…
PublishedA.R. Field D. Dunai Y-C Ghim P. Hill B. Mcmillan C.M. Roach S. Saarelma A.A. Schekochihin S. Zoletnik The Mast Team
Observations of ion-scale density turbulence of relative amplitude are available on the Mega Amp Spherical Tokamak (MAST) using a 2D (8 radial × 4 poloidal channel) imaging Beam Emission Spectroscopy (BES) diagnostic. Spatial and temporal characteristics of this turbulence, i.e., amplitudes, correlation times, radial and perpendicular correlation …
Published