L. Kogan D. Ryan S. Gibson J. Berkery S. Sabbagh T. Farley P. Ryan K. Verhaugh B. Kool T.A. Wijkamp R. Scannell R. Sarwar C. Wade the MAST-U team
The MAST-U spherical tokamak has extensive capabilities to produce and explore strongly shaped plasmas and alternative divertor configurations, especially the Super-X. Robust and accurate reconstructions of plasma equilibria are the foundation of many physics analyses, as well as being important intershot for informing operation of the tokamak. …
PreprintS.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…
PreprintK. D. Lawson E. Pawelec I. H. Coffey M. Groth A. G. Meigs
The properties of tungsten make it ideal for use as a plasma facing surface in the divertor of large plasma machines such as JET and ITER. However, the intense heat and particle fluxes that fall on the divertor surfaces lead to its release from these surfaces into the plasma and it is necessary to model its transport from the divertor and plasma…
PreprintXu Yang Yueqiang Liu Wei Xu Yuling He Guoliang Xia
The influence of negative plasma triangularity on the n=1 (n is the toroidal mode number) tearing mode (TM) stability has been numerically investigated, with results compared to that of the positive triangularity counterpart. By matching the safety factor profile for a series of toroidal equilibria, several important plasma parameters, including th…
Preprint PublishedS Henderson M Bernert D Brida M Cavedon P David R Dux O Fevrier A Jarvinen A Kallenbach R McDermott M O Mullane
This paper addresses two key issues regarding plasma exhaust in future fusion reactors. Firstly, using newly developed spectroscopic models to measure the divertor concentration of Ne and Ar, it is shown that the experimental detachment threshold on ASDEX Upgrade with Ar-only, an Ar+N mixture, and a Ne+N mixture scales as expected in comparison wit…
Preprint PurchaseA. 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…
PreprintR O Dendy B Chapman B C G Reman J W S Cook
Observations of radiation in the ion cyclotron range of frequencies from the KSTAR tokamak and LHD heliotron-stellarator show that energetic neutral beam injected (NBI) ion populations can relax collectively in the edge plasma near the injection point. The resulting radiation is ion cyclotron emission (ICE), whose spectrum has strongly suprather…
PreprintW.G. Fuller S. Allan B. Hnat N.R. Walkden
With MAST-U’s first plasma achieved in November 2020 and one of the key aims of the first experimental programme being to study exhaust physics, there is strong motivation to develop a new probe designed specifically for studying edge turbulence effects in the exhaust region of MAST-U. To create a new versatile probe, the design will be valida…
PreprintA I Zalzali K E Thome R O Dendy S C Chapman B Chapman J W S Cook M A Van Zeeland N A Crocker G H DeGrandchamp
Ion cyclotron emission (ICE) comprises strongly suprathermal emission, which has spectral peaks at multiple ion cyclotron harmonics. ICE is driven by the magnetoacoustic cyclotron instability, resulting from an inversion in the velocity-space distribution of the minority energetic ions. Recent experimental studies on DIII-D (K E Thome et al
PreprintO.P. Bardsley T.C. Hender B.C. Lyons N.M. Ferraro S.N. Gerasimov JET contributors
Disruptions pose a serious challenge for future tokamak power plants; at the large stored thermal and magnetic energies of ITER and DEMO plasmas, the heat loads and electromagnetic forces during disruptions must be mitigated. With this objective, JET experiments employing impurity shattered pellet injection (SPI) have recently been undertaken. W…
Preprint