Y. Liu D. Ryan A. Kirk L. Li W. Suttrop M. Dunne R. Fischer J.C. Fuchs B. Kurzan P. Piovesan M. Willensdorfer The ASDEX Upgrade team The EUROfusion MST1 team
The plasma response to the vacuum resonant magnetic perturbation (RMP) fields, produced by the ELM control coils in ASDEX Upgrade experiments, is computationally modelled using the MARS-F/K codes [Liu Y.Q. et al 2000 Phys. Plasmas 7 3681; Liu Y.Q. et al 2008 Phys. Plasmas 15 112503]. A systematic investigation is carried out, considering various pl…
Preprint PublishedF.J. Casson C. Angioni E.A. Belli R. Bilato P. Mantica T. Odstrcil T Puetterich M. Valisa L. Garzotti C. Giroud J. Hobirk C.F. Maggi J. Mlynar M.L. Reinke JET EFDA contributors ASDEX-Upgrade team
The effects of poloidal asymmetries and heated minority species are shown to be necessary to accurately describe heavy impurity transport in present experiments in JET and ASDEX Upgrade. Plasma rotation, or any small background electrostatic field in the plasma, such as that generated by anisotropic external heating can generate strong poloidal den…
Preprint PublishedI.T. Chapman V. Igochine M. Maraschek P.J. Mccarthy G. Tardini The Asdex Upgrade Ecrh Group The Asdex Upgrade Team
Sawtooth control using steerable electron cyclotron current drive (ECCD) has been demonstrated in ASDEX Upgrade plasmas with a significant population of energetic ions in the plasma core and long uncontrolled sawtooth periods. The sawtooth period is found to be minimised when the ECCD resonance is swept to just inside the q = 1 surface. By utilisin…
PublishedV. Igochine I. T. Chapman V. Bobkov S. Günter M. Maraschek D. Moseev G. Pereversev M. Reich J. Stober Asdex Upgrade Team
It is often observed that large sawteeth trigger the neoclassical tearing mode (NTM) well below the usual threshold for this instability. At the same time, fast particles in the plasma core stabilize sawteeth and provide these large crashes. The paper presents results of first experiments in ASDEX Upgrade for destabilization of fast particle stabil…
PublishedA. Kirk H.W. Muller A. Herrmann M. Kocan V. Rohde P. Tamain The Asdex Upgrade Team
The radial propagation of type-I ELMs in ASDEX Upgrade has been measured using a number of techniques. The most reliable technique uses a filament probe to measure the time difference between two separated probes and yields a mean radial velocity obtained of ~1.5 kms -1 . The radial velocity calculated using a time of flight technique suffers from …
PublishedI. T. Chapman M. F. De Bock S. D. Pinches M. R. Turnyanskiy Mast Team V. G. Igochine M. Maraschek G. Tardini Asdex Upgrade Team
Sawtooth behavior has been investigated in plasmas heated with off-axis neutral beam injection in ASDEX Upgrade [A. Herrmann and O. Gruber, Fusion Sci. Technol. 44 , 569 (2003)] and the Mega-Ampere Spherical Tokamak MAST [A. Sykes and et al. , Nucl. Fusion 41 , 1423 (2001)]. Provided that the fast ions are well confined, the sawtooth period is foun…
PublishedM. Manso A. Silva P. Varela D. Borba P. Lang L. Cupido I. Nunes G. Conway The Asdex Upgrade Team.
We present a study performed in ASDEX Upgrade H mode regime based on results from the broadband FM-CW reflectometry diagnostic, equipped with the unique capability of measuring the plasma density profile both at the low and high field sides of the tokamak. The plasma edge dynamics due to fast events such as the Edge Localized Modes (ELMs) is analyz…
PublishedS. Günter A. Gude M. Maraschek S. Sesnic H. Zohm Asdex Upgrade Team D. F. Howell
High confinement [with H 1 , ITERH- 98 y, 2 ] at b N 2.3 has been found in ASDEX Upgrade discharges with existing m, n 3, 2 neoclassical tearing modes (NTMs). The reason for the high confinement at high b N values is a transition of the NTMs into the so-called frequently interrupted regime. In this regime, the NTM growth is frequently interrupted b…
Published