E. Havlícková W. Fundamenski M. Wischmeier G. Fishpool D. Coster
As part of preparations for the new Super-X divertor (SXD) on MAST, the influence of long divertor leg is modelled by SOL transport codes. The SOLPS5.0 package is used to study the effect of the expanded divertor in two dimensions and a comparison between the conventional geometry (standard short divertor) and the SXD geometry is presented. We focu…
PublishedI. T. Chapman A. Kirk C. J. Ham J. R. Harrison Y. Q. Liu et al.
Type-I Edge Localised Modes (ELMs) have been mitigated in MAST through the application of n = 3, 4, and 6 resonant magnetic perturbations. For each toroidal mode number of the non-axisymmetric applied fields, the frequency of the ELMs has been increased significantly, and the peak heat flux on the divertor plates reduced commensurately. This increa…
PublishedD. Dickinson C. M. Roach S. Saarelma R. Scannell A. Kirk H. R. Wilson
Plasma equilibria reconstructed from the Mega-Amp Spherical Tokamak have sufficient resolution to capture plasma evolution during the short period between edge-localized modes (ELMs). Immediately after the ELM, steep gradients in pressure, P , and density, n e , form pedestals close to the separatrix, and they then expand into the core. Local gyrok…
PublishedJohn Connor Colin Windsor
Derek Robinson was a leading UK plasma physicist of his generation. After an early success in measuring the electron temperature in the ZETA plasma through the Thomson scattering of laser light, he became a key member of the team from Culham Laboratory sent to Moscow in 1968 to verify the high temperatures claimed by the Russians for their T3 tokam…
PublishedJ. Huang S. Lisgo G. Maddison The Mast Team
The retention of deuterium fuel during MAST discharges has been studied using the method of global gas balance. The results show that with inter-shot 4 He- GDC, the total number of particles retained for a discharge increases with total number of injected particles, and the total retention fraction stays very high, mostly around 80%, and can be alm…
PublishedAnthony J. Webster
The surface or “skin” current that can flow at a perturbed interface between plasma and vacuum is considered in the approximation where a surface marks a sharp transition from plasma to vacuum. A short magnetohydrodynamic calculation gives an exact and general expression for the component perpendicular to the average of the magnetic field eithe…
PublishedM. Kovari B. Crowley S. J. Cox
Measurements have been made of the emittance plot of a partly neutralized positive ion beamlet, using a slit, a polymer target, and an infrared camera. This thermographic approach is intrinsically linear and absolute since the properties of the target are known and approximately independent of temperature. It is sufficiently sensitive that only one…
PublishedS. Khakshouri D. Alfè D. M. Duffy
Irradiation of a metal by lasers or swift heavy ions causes the electrons to become excited. In the vicinity of the excitation, an electronic temperature is established within a thermalization time of 10–100 fs, as a result of electron-electron collisions. For short times, corresponding to less than 1 ps after excitation, the resulting electronic…
PublishedR. Prokopowicz M. Scholz A. Szydlowski S. Popovichev
The paper reports on experiments carried out at JET to test the possibility of using some activating materials (e.g. 89Y, 167Er, 204Pb, 180Hf, 111Cd, etc.) to perform multi-foil neutron activation measurements. It is shown that apart from indium other materials can be successfully used in these measurements delivering more exact information about f…
PublishedP.U. Lamalle M. Shannon A. Borthwick S. Brons B. Chuilon P. Dumortier F. Durodié M. Evrard R. Goulding F. Louche A. Messiaen M. Nightingale D. Swain M. Vervier
The design of the ITER ICRF system has been under revision for several years. The paper presents the status of the design proposal based on a 24 strap antenna plug (6 poloidal by 4 toroidal short radiating conductors) in which the straps are passively combined in 8 poloidal triplets by means of 4-port junctions. These triplets are connected in para…
Published