S. Murphy-Sugrue J. Harrison N. Walkden P. Bryant J. W. Bradley
Ball-pen probes have been deployed in the SOL of numerous magnetic confinement experiments to make direct measurements of the plasma potential. They have also been used simultaneously with Langmuir probes to make fast measurements of the electron temperature. Despite strong empirical evidence for the success of the BPP it lacks a theoretical underp…
Preprint PublishedD. Moulton J. Harrison B. Lipschultz D. Coster
We show that a central characteristic of Super-X divertors, parallel area expansion fR (de ned as the ratio of the elementary area normal to the magnetic field at the target to that at the X-point, also known as total flux expansion), significantly changes the characteristics of the target plasma for fixed upstream conditions. To isolate the effect…
Preprint PublishedJ.R. Harrison W.A.J. Vijvers C. Theiler B.P. Duval S. Elmore B. Labit B. Lipschultz S.H.M. van Limpt S.W. Lisgo C.K. Tsui H. Reimerdes U. Sheikh K.H.A. Verhaegh M. Wischmeier The MST TCV Teams
Divertor detachment in the TCV tokamak has been investigated through experiments and modelling. Density ramp experiments were carried out in ohmic heated L-mode pulses with the ion B drift directed away from the primary X-point, similar to previous studies [pitts2001]. Before the roll-over in the ion current to the outer strike point, C III and D? …
Preprint PublishedH. 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 PublishedH. Tanabe T. Yamada T. Watanabe K. Gi K. Kadowaki M. Inomoto R. Imazawa M. Gryaznevich R. Scannell N. Conway B. Crowley K. G. McClements I. Fitzgerald C. Michael J. Harrison A. Meakins N. Hawkes T. OGorman F. Cheng Y. Ono The Mast Team
This paper describes a recent advances in merging/reconnection experiments in MAST, namely tomographic ion Doppler spectroscopy capability from 2013 which solves the problem of the absence of ion temperature profile measurement during the solenoid-less startup. Providing 32 channel line-integrated spectra from 0.25m< rtangential <1.1m are con…
PreprintA. Kirk A.J. Thornton J.R. Harrison F. Militello N.R. Walkden The MAST Team The EUROfusion MST1 Team
Clear filamentary structures are observed at the edge of tokamak plasmas. These filaments are ejected out radially and carry plasma in the far Scrape Off Layer (SOL) region, where they are responsible for producing most of the transport. A study has been performed of the characteristics of the filaments observed in L-mode plasma on MAST, using visi…
Preprint PublishedS. Elmore S.Y. Allan G. Fishpool A. Kirk A.J. Thornton N.R. Walkden J.R. Harrison The MAST Team
In future nuclear fusion reactors high heat load events, such as edge-localised modes (ELMs), can potentially damage divertor materials and release impurities into the main plasma, limiting plasma performance. The most difficult to handle are type I ELMs since they carry the largest fraction of energy from the plasma and therefore deposit the large…
Preprint PublishedH. Tanabe T. Yamada T. Watanabe K. Gi K. Kadowaki 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. OGorman C. Z. Cheng Y. Ono The MAST Team
Electron and ion heating characteristics during merging reconnection startup on the MAST spherical tokamak have been revealed in detail using 130 channel YAG- and 300 channel Ruby-Thomson scattering system and a new 32 chord ion Doppler tomography diagnostic. Detailed 2D profile measurements of electron and ion temperature together with electron de…
Preprint PublishedE. Havlíčková J. Harrison B. Lipschultz G. Fishpool A. Kirk A. Thornton M. Wischmeier S. Elmore S. Allan
SOLPS simulations of MAST-U have been carried out to identify in more detail the physics and operational properties of novel divertor configurations such as Super-X divertor (SXD), in particular the physics of detachment. A well diagnosed L-mode discharge from MAST has been utilised to determine L-mode transport coefficients representative for MAST…
Preprint PublishedA. Kirk W. Suttrop I.T. Chapman Yueqiang Liu R. Scannell A.J. Thornton L. Barrera Orte P. Cahyna T. Eich R. Fischer C. Fuchs C. Ham J.R. Harrison MW. Jakubowski B. Kurzan S. Pamela M. Peterka D. Ryan S. Saarelma B. Sieglin M. Valovic M Willensdorfer MAST and ASDEX Upgrade Teams
Sustained Edge Localised Mode (ELM) mitigation has been achieved on MAST and AUG using RMPs with various toroidal mode numbers over a wide range of low to medium collisionality discharges. The ELM energy loss and peak heat loads at the divertor targets have been reduced. The ELM mitigation phase is typically associated with a drop in plasma density…
Preprint Published