H. Wu P. Shi F. Subba H. Sun M. Wischmeier R. Zanino the ASDEX Upgrade Team
The High Field High Density Region (HFSFD) has been experimentally observed in both divertor and limiter tokamak devices. In order to numerically reproduced the HFSHD region in the limiter tokamak device J-TEXT, we first performed SOLPS-ITER simulations on the J-TEXT limiter tokamak with the activation of drifts, which is associated with the HFSHD …
PreprintN. 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 PublishedH. J. Sun R. J. Goldston A. Huber X. Q. Xu J. Flanagan D. C. McDonald E. de la Luna M. Maslov J. R. Harrison F. Militello J. Fessey S. Cramp JET Contributors
A study of a dataset of JET H-mode plasma with the Be/W ITER-like wall (JET-ILW) shows that reaching the edge MHD ballooning limit leads to confinement degradation. However, unlike JET plasmas with a carbon wall (JET-C), the JET-ILW plasmas stay in a marginal dithering phase for a relatively long period, associated with a higher (20%) H-mode den…
Preprint PublishedP.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 PublishedA. Loarte A. R. Polevoi M. Schneider S.D. Pinches E. Fable E. Militello Asp Y. Baranov F. Casson G. Corrigan L. Garzotti D. Harting P. Knight F. Koechl V. Parail D. Farina L. Figini H. Nordman P. Strand R. Sartori
The optimum conditions for access to and sustainment of H-mode plasmas and their expected plasma parameters in the Pre-Fusion Power Operation 1 (PFPO-1) phase of the ITER Research Plan, where the additional plasma heating will be provided by 20 MW of Electron Cyclotron Heating (ECH), are assessed in order to identify key open R&D issues. The as…
Preprint PublishedM. Kong F. Felici O. Sauter C. Galperti T. Vu C. Ham T.C. Hender M. Maraschek M. Reich the TCV team the ASDEX Upgrade team the MAST team the EUROfusion MST1 team
This paper presents recent progress on the studies of neoclassical tearing modes (NTMs) on TCV, concerning the new physics learned and how this physics contributes to a better real-time (RT) control of NTMs. A simple technique that adds a small (sinusoidal) sweeping to the target electron cyclotron (EC) beam deposition location has proven effective…
Preprint PublishedH. J. Sun E. Wolfrum T. Eich A. Kallenbach P. Schneider B. Kurzan U. Stroth the ASDEX Upgrade Team
A survey of the correlation between temperature and density gradient lengths ( and ) has been performed for the near SOL regions in the ASDEX Upgrade tokamak. In common with previous studies, the near SOL temperature and density gradient length ratio, , is found to be close to unity across a wide range of plasmas. However, it is found that it is po…
Preprint PublishedH. J. Sun RJ. Goldston A.Huber XQ. Xu J. Flanagan DC. McDonald E. de la Luna M. Maslov J. Harrison F. Militello J. Fessy S. Cramp JET Contributors
A study of a dataset of JET plasma with the Be/W ITER-like wall (JET-ILW) shows that reaching the edge MHD ballooning limit leads to confinement degradation. However, unlike JET plasma with a carbon wall (JET-C), the JET-ILW plasma stays in a marginal dithering phase for a relatively long period, associated with a higher a ( 20%) H-mode density lim…
Preprint PublishedB. Geiger A. N. Karpushov S. Sharapov R. Akers A. Bock M. Dunne B. Duval M. Fontana L. Giannone J. Hobirk C. Hopf A.S. Jacobsen D. Keeling P. Lauber C. Marini P. ZS. Poloskei M. Salewski O. Sauter P. A. Schneider D. Testa A.J. Van Vuuren M. Willensdorfer TCV Team ASDEX Upgrade Team EUROfusion MST15 Team
The fast-ion transport has been investigated in low-collisionality discharges at ASDEX Upgrade and TCV using offaxis neutral beams. In both devices Alfven eigenmode activity was observed which does, however, not strongly affect the global fast-ion confinement. In contrast, charge exchange losses have been identified to have a strong effect. At TCV …
PreprintS. 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 Published