J. Simpson D. Moulton C. Giroud F. Casson M. Groth A. Chankin L. Horvath D. S. Gahle F. Kochl
EDGE2D-EIRENE simulations show that for a H-mode JET discharge (92168) the dominant atomic neutral deuterium source at the separatrix originates from the inner divertor target. Within JETTO-EIRENE neutral sources are placed at the X-point and outer midplane (OMP). For fixed electron and ion temperature, transport and neutral temperature it is obser…
Preprint PublishedR.A. Tinguely P.G. Puglia N. Fil S. Dowson M. Porkolab A. Dvornova A. Fasoli M. Fitzgerald G.T.A. Huysmans M. Maslov S. Sharapov D. Testa JET Contributors
This paper presents a dedicated study of plasma-antenna (PA) coupling with the Alfvén Eigenmode Active Diagnostic (AEAD) in JET. Stable AEs and their resonant frequencies f, damping rates < 0, and toroidal mode numbers n are measured for various PA separations and limiter versus X-point magnetic cofigurations. Two stable AEs are observed to be …
Preprint PublishedK D Lawson I H Coffey F Rimini I Ksiazek
Divertor Monitoring Pulses (DiMPle) have been run in JET from the C35 campaign onwards. They provide an opportunity to study the impurity contamination of the plasma when it is limited by different surfaces within the machine, as well as the longer term behaviour of the impurities. In these discharges the plasma is first limited on the outer wall, …
Preprint PublishedS.Pamela G.Huijsmans A.J.Thornton A.Kirk S.F.Smith M.Hoelzl T.Eich JET Contributors the MAST Team the JOREK Team
Typically applied to non-linear simulations of MHD instabilities relevant to magnetically confined fusion, the JOREK code was originally developed with a 2D grid composed of isoparametric bi-cubic Bezier finite elements, that are aligned to the magnetic equilibrium of tokamak plasmas. To improve the applicability of these simulations, the grid-gene…
Preprint PublishedG. Pucella E. Giovannozzi P. Buratti E. Alessi F. Auriemma D. Brunetti P. J. Lomas S. Nowak C. Sozzi JET Contributors
In this work the mechanisms that can lead to disruptive MHD instabilities in the termination phase of plasma pulses on JET are investigated. It is shown that the broadening or the shrinking of the current density profile, as a consequence of a core hollowing or a edge cooling of the electron temperature profile, can lead to the destabilization o…
Preprint PublishedG. M. Staebler J. Candy E. Belli J. E. Kinsey N. Bonanomi B. Patel
The findings of an investigation into the properties of the three dimensional (3D) saturated fluctuation intensity of the electric potential in gyrokinetic turbulence simulations is presented. Scans in flux surface elongation and Shafranov shift are used to isolate the tokamak geometric dependencies. The potential intensity required in order to …
Preprint PublishedK. K. Kirov E. Belonohy C. D. Challis J. Eriksson D. Frigione L. Garzotti L. Giacomelli J. Hobirk A. Kappatou D. Keeling D. King E. Lerche P. J. Lomas M. Nocente C. Reux F. G. Rimini A. C. C. Sips D. Van Eester JET Contributors
Achieving high neutron yields in today’s fusion research relies on high power auxiliary heating in order to attain required core temperatures. This is usually achieved by means of high Neutral Beam (NB) and Radio Frequency (RF) power. Application of NB power is accompanied by production of fast beam ions and associated Beam-Target (BT) reactio…
Preprint PublishedM. R. Hardman M. Barnes C. M. Roach
Magnetised plasma turbulence can have a multiscale character: instabilities driven by mean temperature gradients drive turbulence at the disparate scales of the ion and the electron gyroradii. Simulations of multiscale turbulence, using equations valid in the limit of infinite scale separation, reveal novel cross-scale interaction mechanisms in …
Preprint PublishedD. Hoare F. Militello J.T. Omotani F. Riva S. Newton T. Nicholas D. Ryan N.R. Walkden
The role of magnetic perturbations generated by filaments in the scrape-off layer is investigated by performing simulations of 3D seeded filaments with an electromagnetic numerical code which includes sheath boundary conditions. Depending on the plasma , three smoothly connecting regimes were identified: an electrostatic regime where the magnet…
Preprint PublishedYuling He Yueqiang Liu Xu Yang Guoliang Xia Li Li
Modification of the external tearing index, Δ’ext , by magnetic feedback is analytically investigated, for the purpose of controlling the resistive plasma resistive wall mode (RP-RWM). The matching method is pursued, by deriving expressions for the close-loop Δ’ext and by linking it to the counterpart from the inner layer. Various…
Preprint Published