Robert J Ewart Felix I Parra Alessandro Geraldini
The Debye sheath is shown to vanish completely in magnetised plasmas for a sufficiently small angle between the magnetic field and the wall that depends on the current to the wall. When the Debye sheath vanishes, there is still a potential drop between the wall and the plasma across the magnetic presheath. The magnetic field angle corresponding …
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…
PreprintI. Ivanova-Stanik C.D. Challis A. Chomiczewska J. Hobirk A. Huber. A Kappatou E. Lerche G. Telesca R. Zagorski
The aim of this paper is to numerically study the influences of the impurities on the high power hybrid discharges in the JET ILW configuration in the DD and DT scenarios. Numerical simulations with the COREDIV code of hybrid discharges with 32MW auxiliary heating, 2.2MA plasma current and 2.8T toroidal magnetic field in the ITER-like wall (ILW)…
PreprintE. Tholerus L. Garzotti Y. Baranov G. Corrigan F. Eriksson D. Farina L. Figini D.M. Harting F. Koechl A. Loarte E. Militello Asp H. Nordman V. Parail S.D. Pinches A.R. Polevoi R. Sartori P. Strand
An important part of the ITER Research Plan [1] is the Pre-Fusion Power Operation (PFPO) phase, which includes demonstration of H-mode plasma operation and the commissioning of ELM control systems. However, since hydrogen or helium are the main ion species in PFPO plasmas, the L–H power threshold PL–H is expected to be cons…
PreprintG. Szepesi L.C. Appel E. de la Luna L. Frassinetti P. Gaudio M. Gelfusa S. Gerasimov N.C. Hawkes M. Sertoli D. Terranova
Many of the essential data analysis procedures for a tokamak experiment rely on the knowledge of the magnetic field structure obtained from MHD force balance. On JET, the code that is responsible for computing the magnetic equilibrium is called EFIT++. Interpretation of JET data has been challenging due to inconsistencies between diagnostic meas…
PreprintFrancesco Palermo G. D. Conway E. Poli C. M. Roach
Geodesic acoustic modes (GAMs) represent the oscillating counterpart of the zonal flow and can affect transport with their interaction on turbulence eddies. GAMs have been observed in many experiments and modelled under different conditions, but because of their variety of characteristics, we do not yet have a complete picture of their dynamics.…
PreprintYuling He Yueqiang Liu Li Li Xu Yang Guoliang Xia
Magnetic feedback stabilization of the tearing mode (TM) is numerically investigated, utilizing the MARS-F code (Liu et al 2000 Phys. Plasmas 7 3681) for toroidal tokamak equilibria. Magnetic feedback generally (partially or fully) stabilizes the TM independent of the feedback coil configuration and the type of plasma equilibrium. The best c…
PublishedJacob Chapman Pui-Wai Ma Sergei Dudarev
Fundamental flaws in the Heisenberg Hamiltonian are highlighted in the context of its application to BCC Fe, including the particular issues arising when modelling lattice defects. Exchange integrals are evaluated using the magnetic force theorem. The bilinear exchange coupling constants are calculated for all the interacting pairs of atomic ma…
PublishedK. Verhaegh A.C. Williams D. Moulton B. Lipschultz B.P. Duval O. Février A. Fil J. R. Harrison N. Osborne H. Reimerdes C. Theiler
Divertor detachment requires plasma-neutral interactions which dissipate momentum, power and particles simultaneously. Plasma-molecular interactions can result in molecular ions which react with the plasma. This can contribute to detachment through molecular activated recombination (MAR) and molecular activated dissociation (MAD), both of which cre…
Preprint Published