Guoliang Xia Yueqiang Liu T.C. Hender K.G. McClements E. Trier E. Tholerus
In this work, the MARS-F/K codes (Liu Y Q et al 2000 Phys. Plasmas 7 3681 & Liu Y Q et al 2008 Phys. Plasmas 15 112503) are utilized to model the passive and active control of the n=1 (n is the toroidal mode number) resistive wall mode (RWM) in a spherical tokamak (aspect rat…
Preprint PublishedGuoliang Xia T.C. Hender Yueqiang Liu E. Trier
The Spherical Tokamak for Energy Production (STEP) is a UKAEA program that aims to deliver a prototype fusion energy plant and a path to commercial viability of fusion [1]. The low aspect ratio spherical tokamak is attractive because of its potential to achieve high normalized beta βN operation, and the fusion power ~β…
PreprintM. Kong E. Nardon M. Hoelzl D. Bonfiglio D. Hu U. Sheikh A. Boboc P. Carvalho T.C. Hender S. Jachmich K.D. Lawson S. Silburn Ž. Štancar R. Sweeney G. Szepesi the JOREK team JET contributors
Shattered pellet injection (SPI), with research started in recent years, is the current concept for the ITER disruption mitigation system (DMS) to prevent disruption-related damage. Compared with impurity SPI, pure deuterium (D2) SPI could contribute to runaway electron (RE) avoidance in ITER via a strong dilution cooling before the thermal quen…
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…
PreprintM. Kong F. Felici O. Sauter C. Galperti T. Vu C. Ham T.C. Hender M. Maraschek M. Reich the TCV team the ASDEX Upgrade team the MAST team the EUROfusion MST1 team
This paper presents recent progress on the studies of neoclassical tearing modes (NTMs) on TCV, concerning the new physics learned and how this physics contributes to a better real-time (RT) control of NTMs. A simple technique that adds a small (sinusoidal) sweeping to the target electron cyclotron (EC) beam deposition location has proven effective…
Preprint PublishedO. P. Bardsley T. C. Hender
Reduced activation ferritic steels are an attractive option for use in large structural components surrounding tokamak plasmas in future fusion power plants, but their ferromagnetic response to the confining magnetic fields must be properly understood. Simultaneously, the advantages of operating at high plasma elongation push tokamak designs tow…
Preprint PublishedL. Piron T. C. Hender E. Joffrin F. Auriemma P. Buratti R. Paccagnella P. Zanca C. Challis S. Gerasimov R. B. Henriques L. Marrelli P. Lomas F. Rimini D. Terranova
The presence of Error Fields (EFs) in magnetic fusion devices can affect energy confinement and plasma stability by braking plasma rotation, by inducing fast particle losses and being amplified when exploring high-b regimes. The resulting EF Locked Modes (LMs) can be stabilized by NBI injection through the rotation shielding mechanism. However, …
Preprint PublishedStuart I. Muldrew Hanni Lux Tim C. Hender Bhavin Patel Peter J. Knight Garry M. Voss Howard R. Wilson
Spherical Tokamaks offer a number of potential advantages for a future fusion power plant. They have a high ratio of thermal to magnetic field pressure (beta) and strong flows, either of which could result in reduced turbulence. Fewer Toroidal Field (TF) coils and a different geometry offers the potential for new methods of remote maintenance …
Preprint PublishedS.N. Gerasimov G Artaserse P. Buratti I.S. Carvalho E. de la Luna T.C. Hender R.B. Henriques P.J. Lomas E. Matveeva S. Moradi L. Piron F.G. Rimini G. Szepesi L.E. Zakharov JET Contributors
An n = 1 locked, or slowly rotating, mode has been observed in most pulses prior to JET disruptions. However, a small fraction of non-disruptive pulses has a locked mode which eventually vanishes without disruption. Hence, on JET the locked mode amplitude is routinely used as an indicator of unhealthy plasma. There are two threshold levels…
Preprint PublishedSergei Gerasimov P. Abreu G Artaserse M. Baruzzo P. Buratti I.S. Carvalho I.H. Coffey E. de la Luna T.C. Hender R.B. Henriques R. Felton U. Kruezi P.J. Lomas P. McCullen M. Maslov E. Matveeva S. Moradi L. Piron F.G. Rimini W. Schippers G. Szepesi M. Tsalas L.E. Zakharov
The paper presents an analysis of disruptions occurring during JET-ILW plasma operations covering the period from the start of ILW (ITER-like wall) operation up to completion of JET operation in 2016. The total number of disruptions was 1951 including 466 with deliberately induced disruptions. The average disruption rate of unintended disruptions i…
Preprint Published