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…
PreprintFabio Federici Matthew L. Reinke Bruce Lipschultz Andrew J. Thornton James R. Harrison Jack J. Lovell Peter Ryan Matthias Bernert Hendrik F. Meyer the MAST Upgrade team
A prototype infrared video bolometer (IRVB) was succesfully deployed in MAST-U, the first deployment of such a diagnostic in spherical tokamaks. The IRVB was designed to study the radiation around the x-point and has the potential to return emissivity profiles of unprecedented spatial resolution. The system was fully characterised prior installatio…
Preprint PurchaseN. VIANELLO N. WALKDEN M. DUNNE B. LOMANOWSKI E. WOLFRUM C. TSUI A. STAGNI M. GRIENER B. TAL T. EICH D. REFY D. BRIDA O. FEVRIER M. AGOSTINI H. DE OLIVEIRA S. ALEIFERIS M. BERNERT J. BOEDO M. BRIX D. CARRALERO I. CARVALHO L. FRASSINETTI C. GIROUD A. HAKOLA A. HUBER . KARHUNEN J, A. KARPUSHOV B. LABIT A. MEIGS V. NAULIN T. PEREIRA C. PEREZ VON THUN H. REIMERDES C. THEILER the ASDEX Upgrade Team the TCV team the EUROfusion MST1 Team the JET Contributors
The evolution of SOL density profiles and fluctuations have been studied at different recycling levels in 3 different tokamaks, ASDEXUpgrade, TCV and JET, all operated in HMode. In all devices we clearly observe an increase of far SOL efolding length at high …
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 PublishedN. Vianello D. Carralero C. K. Tsui V. Naulin M. Agostini J. Boedo B. Labit C. Theiler D. Aguiam S. Allan M. Bernert S. Costea I. Cziegler H. De Oliveira J. Galdon-Quiroga G. Grenfell A. Hakola C. Ionita H. Isliker A. Karpushov J. Kovacic B. Lipschultz R. Mauriozio K. McClements F. Militello J. Olsen J. J. Rasmussen T. Ravensbergen H. Reimerdes B. Schneider R. Schrittwieser M. Spolaore K. Verhaegh J. Vicente N. Walkden W. Zhang E. Wolfrum the ASDEX Upgrade Team the TCV team the EUROfusion MST1 Team
A detailed cross-device investigation on the role of filamentary dynamics in high density regimes has been performed within the EUROfusion framework comparing ASDEX-Upgrade (AUG) and TCV tokamaks. Both devices have run density ramp experiments at different levels of plasma current, keeping toroidal field or q95 constant in order to disentangle the …
Preprint 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. Carr A. Meakins S. Silburn J. Karhunen M. Bernert C. Bowman A. Callarelli P. Carvalho C. Giroud J. Harrison S. Henderson A. Huber B. Lipschultz T. Lunt D. Moulton F. Reimold ASDEX Upgrade team JET contributors MAST-Upgrade team the EUROfusion MST1 Team
Ray-tracing techniques are applied to divertor filtered imaging, a diagnostic that has long been plagued by polluting reflected light features in metal walled fusion machines. A physically realistic surface reflection model is developed from a Cook-Torrence microfacet BRDF model. Camera calibration images of in-vessel point lights at JET are use…
Preprint PublishedM. Carr A. Meakins M. Bernert P. David C. Giroud J. Harrison S. Henderson B. Lipschultz F. Reimold the EUROfusion MST1 Team ASDEX Upgrade team
Ray-tracing techniques are applied to bolometry, a diagnostic particularly sensitive to machine geometry due to the effect of volume sampling. Sightlines from the ASDEX-Upgrade bolometer foils were ray-traced with a path tracing algorithm, where the optical path is represented by a statistical bundle of ray paths connecting the foil surface with th…
Preprint Published