N.R.Walkden B.D.Dudson C.Ham F.Militello D.Moulton F.Riva J.T.Omotani
A firm grasp of transport processes perpendicular to the magnetic field line is required in order to understand and predict heat and particle fluxes to divertor components in tokamaks. Perpendicular transport from the hot core into the scrape-off layer (SOL) upstream impacts the SOL profile at the divertor via parallel streaming along the magnetic …
Preprint PurchaseS. S. Henderson M. Bernert S. Brezinsek M. Carr M. Cavedon R. Dux D. S. Gahle J. Harrison B. Lipschultz B. Lomanowski A. Meigs M. O’Mullane F. Reimold M. L. Reinke S. Wiesen the EUROfusion MST1 team the ASDEX Upgrade team JET contributors
Reducing the plasma power exhaust impacting on plasma facing components during steady state operation is one of the major design issues in future tokamaks such as ITER. Impurity seeding, e.g. with N, is one method of achieving this and has been used for a long time in tokamak research [1]. In this work we exploit a recently developed spectroscopic …
Preprint PublishedC.J. Ham S.C. Cowley H.W. Wilson
The nonlinear phase of MHD ballooning modes determines whether they are essentially benign or disruptive. Disruptive or hard limits are produced by ballooning modes across magnetic confinement fusion, for example; as ELMs, some tokamak disruptions [1], and perhaps the LHD Core Density Collapse [2]. This work improves our understanding of how these …
Preprint PublishedV.H. Chen F.I. Parra J.C. Hillesheim
The Doppler Backscattering (DBS) microwave diagnostic enables the non-perturbative characterisation of density fluctuations and flows, both at the edge and the core of the plasma. The large magnetic pitch angle (up to 35 degrees, compared to 15 degrees in standard tokamaks like JET) and the time-varying magnetic equilibrium make the use of DBS in s…
Preprint PublishedD A Ryan L Piron A Kirk Y Q Liu M Dunne L Li B Dudson W Suttrop the ASDEX Upgrade team the EUROfusion MST1 team
Edge Localised Modes (ELMs) in H-mode tokamak plasmas may be controlled or entirely suppressed by applying 3D magnetic perturbations (MPs). The applied perturbation is amplified by the plasma response, and it has previously been established that the size of the peeling component of this response is a reliable indicator for expected ELM control on A…
PreprintK.V. Ellis H. Lux E. Fable R. Kembleton M. Siccinio
Systems codes are used in the conceptual phases of fusion reactors design. They employ a multitude of simplified models to simulate an entire power plant and ensure that designs are self-consistent, viable and optimised with respect to a given figure of merit. Their strength is the fast determination of an overall design. However, their output shou…
Preprint PublishedR O Dendy B Chapman S C Chapman K G McClements G S Yun S G Thatipamula M H Kim
During ELM crashes in deuterium plasmas in the KSTAR tokamak, the emitted electromagnetic radiation includes features with sharp spectral structure in the frequency range up to ~900MHz. Cases where the spectral peaks below ~500MHz correspond to proton cyclotron harmonics at the outer midplane edge are explained (B Chapman et al., Nucl.…
Preprint PublishedA. R. Field L. Frassinetti C. Maggi S. Saarelma JET contributors
Empirically-based power-balance calculations of the inter-ELM separatrix loss power are presented for JET pulses with both the carbon- (JET-C) and ITER-like (JET-ILW) walls, to facilitate comparisons with results of on-going, non-linear gyro-kinetic calculations of pedestal heat transport, e.g. as reported in [1]. These might be able to explain the…
PreprintR. Ochoukov V. Bobkov H. Faugel M. García-Muñoz B. Geiger D. Moseev K. G. McClements S. Nielsen P. Schneider M. Weiland J.-M. Noterdaeme ASDEX Upgrade Team MST1 Team
Ion cyclotron emission (ICE) is a commonly observed feature of magnetized toroidal plasmas in the presence of fast ions. It is generally agreed that this emission is caused by a strongly inverted (in the velocity space) population of confined fast ions originating from either neutral beam injection (NBI), fusion reactions, or acceleration by waves …
Preprint Published