S.F. Smith A. Kirk B. Chapman J. G. Clark C.J. Ham L. Horvath C. F. Maggi R. Scannell S. Saarelma
MAST pedestal data has been analysed, where a pedestal database of 892 shots was obtained, using the new upgraded MAST Thomson Scattering (TS) diagnostic. Various ELM types are discussed, where characteristics and trends of MAST pedestals are shown. The data from the upgraded TS diagnostic confirms pedestal characteristics found in earlier analy…
PreprintA. SABBAGH J.W. BERKERY Y.S. PARK J.H. AHN Y. JIANG J.D. RIQUEZES J. BUTT J. BIALEK J.G. BAK M.J. CHOI S.H. HAHN J. KIM J. KO W.H. KO J.W. LEE J.H. LEE K.D. LEE L. TERZOLO S.W. YOON R.E. BELL M.D. BOYER K. ERICKSON B. LEBLANC M. PODESTA Z.R.WANG J. YOO C. HAM A. KIRK L. KOGAN D. RYAN A. THORNTON J. HOLLOCOMBE F.M. LEVINTON M.GALLANTE
Disruption prediction and avoidance is critical for ITER and reactor-scale tokamaks to maintain steady plasma operation and to avoid damage to device components. The present status and results from the disruption event characterization and forecasting (DECAF) research effort are shown. The DECAF paradigm is primarily physics-based and provides q…
PreprintS.F. Smith S.J.P. Pamela A. Fil M. Hölzl G.T.A. Huijsmans A. Kirk D. Moulton O. Myatra A.J. Thornton H.R. Wilson
The high heat fluxes to the divertor during edge localised mode (ELM) instabilities have to be reduced for a sustainable future tokamak reactor. A solution to reduce the heat fluxes could be the Super-X divertor, this divertor configuration will be tested on MAST-U. ELM simulations for MAST-U Super-X tokamak plasmas have been obtained, using JOR…
PreprintJ. R. Harrison T. Farley G. M. Fishpool A. Kirk B. Lipschultz J. Lovell F. Militello D. Moulton P. Ryan R. Scannell A. J. Thornton K. Verhaegh L. Xiang
The benefits of an optimised Super-X divertor configuration in mitigating the steady-state power and particle fluxes to the surfaces of the MAST Upgrade divertor have been quantified by performing a detailed comparison with a conventional divertor for the first time. In otherwise identical plasmas with conventional and Super-X divertor configu…
PreprintS. Kirk K. Keogh
The maintenance and decommissioning of nuclear reactors requires the rapid cutting and welding of thick-walled pipework, to which laser processing is highly suited. However, the large size and stand-off of current laser heads precludes their use in space constrained areas and incorporation into in-bore processing tools. To address this, novel minia…
Preprint PublishedJ. Leland S. Elmore A. Kirk H. v/d Meiden. J. Scholten S. Allan J. W. Bradley
Measurements made using flush-mounted Langmuir probes (FMPs) in tokamaks are difficult to interpret when operating at grazing angles of magnetic field incidence due to the effects of sheath expansion on the probe collection area. The super-X divertor on the upgraded Mega Ampere Spherical Tokamak (MAST-U) will have very shallow angles of magnetic fi…
Preprint PublishedM. Knolker T. Osborne E. Belli S. Henderson A. Kirk L. Kogan S. Saarelma P. B. Snyder
In preparation for the upcoming MAST-U campaign, pedestal stability of spherical tokamaks is revisited by investigating standard H-mode discharges on MAST. As a step beyond previous studies, both ion and electron profiles are used for obtaining equilibria and a diverse set of pedestals is evaluated. Stability analysis with the ELITE and CGYRO codes…
Preprint PublishedS.A. Sabbagh J.W. Berkery A. Kirk Y.S. Park J.H. Ahn J.M. Bialek Y. Jiang J.D. Riquezes J.G. Bak K. Erickson A.H. Glasser C. Ham J. Hollocombe J. Kim J. Ko W.H. Ko L. Kogan J.H. Lee A. Thornton S.W. Yoon Z.R. Wang
Disruption prediction and avoidance is critical in ITER and reactor-scale tokamaks to maintain steady plasma operation and to avoid damage to device components. The present status and results from the physics-based disruption event characterization and forecasting (DECAF) research effort are shown for multiple tokamak devices. Present analysis of K…
Preprint PublishedS.A. Sabbagh J.W. Berkery Y.S. Park J.H. Ahn Y. Jiang J.D. Riquezes J.G. Bak R.E. Bell M.D. Boyer L. Delgado-Aparicio A.H. Glasser J. Hollocombe J. Kim A. Kirk J. Ko W. Ko L. Kogan B.P. LeBlanc J.H. Lee C.E. Myers L. Terzolo A. Thornton S.W. Yoon
Disruption prediction and avoidance is a critical need for next-step tokamaks such as ITER. The Disruption Event Characterization and Forecasting Code (DECAF) is used to fully automate analysis of tokamak data to determine chains of events that lead to disruptions and to forecast their evolution allowing sufficient time for mitigation or full av…
Preprint PublishedM Valovič P T Lang A Kirk W Suttrop A Bock P J Mc Carthy M Faitsch B Plöckl2 the ASDEX Upgrade team the EUROfusion MST1 team
It is demonstrated that tokamak plasma can be fuelled by pellets while simultaneously maintaining ELM suppression by external resonant magnetic perturbations (RMPs). Pellets are injected from vertical high field site and deposited at outer part of plasma cross section. Each pellet triggers benign MHD event followed by short lived ELM free phase. Th…
Preprint Published