S 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…
PreprintP.A. Schneider C. Angioni L. Frassinetti L. Horvath M. Maslov F. Auriemma M. Cavedon C.D. Challis E. Delabie M.G. Dunne J.M. Fontdecaba Climent J. Hobirk A. Kappatou D.L. Keeling B. Kurzan M. Lennholm B. Lomanovski C.F. Maggi R.M. McDermott T. Pütterich A. Thorman M. Willensdorfer
Experiments in ASDEX Upgrade (AUG) and JET with the ITER-like wall (JET-ILW) are performed to separate the pedestal and core contributions to confinement in H-modes with different main ion masses. A strong isotope mass dependence in the pedestal is found which is enhanced at high gas puffing. This is because the ELM type changes when going fro…
Preprint PublishedS. S. Henderson M. Bernert C. Giroud D. Brida M. Cavedon P. David R. Dux J. R. Harrison A. Huber A. Kallenbach J. Karhunen B. Lomanowski G. Matthews A. Meigs R. A. Pitts F. Reimold M. L. Reinke S. Silburn N. Vianello S. Wiesen M. Wischmeier
While current tokamak experiments are beginning to utilise real-time feedback control systems to manage the plasma exhaust, future tokamaks still require validation of theoretical models used to predict the threshold impurity concentration required to facilitate stationary divertor operation. This work exploits new spectroscopic measurements of …
Preprint PublishedW. Suttrop A. Kirk V. Bobkov M. Cavedon M. Dunne R.M. McDermott H. Meyer R. Nazikian C. Paz-Soldan D.A. Ryan E. Viezzer M. Willensdorfer The ASDEX Upgrade MST1 Teams
Access conditions for full suppression of edge localised modes (ELMs) by magnetic perturbations (MP) in low density high confinement mode (H-mode) plasmas are studied in the ASDEX Upgrade tokamak. The main empirical requirements for full ELM suppression in our experiments are: 1. The poloidal spectrum of the MP must be aligned for best plasma respo…
PublishedS. 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 PublishedM Valovic P T Lang A Kirk W Suttrop M Bernert M Cavedon M Dunne R Fischer L Garzotti L Guimarais F Janky N Leuthold PJ Mc Carthy A Mlynek B Plockl G Tardini E Viezzer E Wolfrum the ASDEX Upgrade team the EUROfusion MST1 team
Pellets are used in ASDEX Upgrade [1] to control plasma density under conditions of ELM control or divertor detachment. In experiments presented here direct fuelling by gas is negligible. Relative pellet size and pellet deposition are aimed to approach those in ITER but differences still remain. ELMs are controlled by n=2 RMPs in feed forward mode …
PreprintM. Willensdorfer T.B. Cote M. Griener D.A. Ryan E. Strumberger W. Suttrop N. Wang M. Cavedon S.S. Denk M. Dunne R. Fischer J. Galdon-Quiroga C.J. Ham C.C. Hegna M. Hoelzl A. Kirk M. Maraschek F. Mink N. Leuthold F. Orain E. P. Seliunin H. Zohm the ASDEX Upgrade Team and the MST1 Team
The impact of the three-dimensional (3D) tokamak geometry from external magnetic perturbations (MPs) on the local edge stability has been examined in high confinement mode (H-mode) plasmas with edge localised modes (ELMs) in ASDEX Upgrade. The 3D geometry has been probed using rigidly rotating MP fields. The measured distortions of the plasma bound…
Preprint PublishedM. Valovič P.T. Lang A. Kirk W. Suttrop M. Cavedon G. Cseh M. Dunne L.R. Fischer L. Garzotti L. Guimarais G. Kocsis A. Mlynek B. Plőckl R. Scannell T. Szepesi G. Tardini A. Thornton E. Viezzer E. Wolfrum The ASDEX Upgrade team The EUROfusion MST1 team
The complete refuelling of the plasma density loss (pump-out) caused by mitigation of Edge Localised Modes (ELMs) is demonstrated on the ASDEX Upgrade tokamak. The plasma is refuelled by injection of frozen deuterium pellets and ELMs are mitigated by external resonant magnetic perturbations (RMPs). In this experiment relevant dimensionless paramete…
Preprint Published