S. C. Guo X. Y. Xu Y. Q. Liu Z. R. Wang
An unstable fishbone-like non-resonant external kink mode (FLEM) is numerically found to be driven by the precessional drift motion of trapped energetic particles (EPs) in both RFP and Tokamak plasmas. The FLEM originates from a stable external ideal kink mode, which is stabilized by a close-fitting ideal conducting wall. In the presence of a suffi…
Preprint PublishedX. Yi A.E. Sand D.R. Mason M.A. Kirk S.G. Roberts K. Nordlund S.L. Dudarev
Using in-situ transmission electron microscopy, we have directly observed nano-scale defects formed in ultra-high purity tungsten by low-dose high energy self-ion irradiation at 30K. At cryogenic temperature lattice defects have reduced mobility, so these microscope observations over a window on the initial, primary damage caused by individual coll…
Preprint PublishedW. N. Lai S. C. Chapman R. O. Dendy
The kinetic evolution in velocity space of a minority suprathermal electron population that is undergoing the anomalous Doppler instability (ADI) is investigated using the results from fully nonlinear numerical simulations that self-consistently evolve particles and fields in a plasma. Electron trajectories in phase space during different stages of…
Preprint PublishedL. Li Y. Q. Liu Y. Liang N. Wang F. C. Zhong Y. Liu
Within the single fluid resistive magnetohydrodynamic model, systematic toroidal modelling efforts are devoted to investigate the plasma response induced screening of the applied external 3D magnetic field perturbations in the presence of sheared toroidal flow. One particular issue of interest is addressed, when the local flow speed approaches zero…
Preprint PublishedF.J. Casson E. Poli C. Angioni R. Buchholz A.G. Peeters
Non-linear local electromagnetic gyrokinetic turbulence simulations of the ITER standard scenario H-mode are presented for the q = 3 / 2 and q = 2 surfaces. The turbulent transport is examined in regions of velocity space characteristic of electrons heated by electron cyclotron waves. Electro- magnetic fluctuations and sub-dominant micro-tearing mo…
Preprint PublishedS. X. Yang S. Wang Y. Q. Liu G. Z. Hao Z. X. Wang X. M. Song A. K. Wang
The magnetohydrodynamic-kinetic hybrid theory has been extensively and successfully applied for interpreting experimental observations of macroscopic, low frequency instabilities, such as the resistive wall mode, in fusion plasmas. In this work, it is discovered that an analytic version of the hybrid formulation predicts a bifurcation of the mode d…
Preprint PublishedT. Markovic Y. Q. Liu P. Cahyna R. Pánek M. Peterka M. Aftanas P. Bílková P. Bohm M. Imríek P. Há?ek J. Havlicek A. Havránek M. Komm J. Urban The COMPASS Team
It has been shown on several tokamaks that application of a Resonant Magnetic Perturbation (RMP) eld on plasma can under certain conditions lead to suppression or mitigation of Edge-Localized Mode (ELM) instabilities. Due to the rotation of the plasma in the RMP eld reference system, currents are induced on resonant surfaces within the plasma, co…
Preprint PublishedM. Valovic L. Garzotti C. Gurl A. Kirk D. Dunai A.R. Field I. Lupelli G. Naylor A. Thornton The MAST Team
The fuelling of plasmas by shallow frozen pellets with simultaneous mitigation of edge- localised modes (ELM) by external magnetic perturbation is demonstrated on the MAST tokamak. In these plasmas post-pellet particle loss is dominated by ELMs. It is shown that the size of post-pellet ELMs can be controlled by external magnetic perturbations. Post…
Preprint PublishedG. Merlo O. Sauter S. Brunner A. Burckel Y. Camenen F. Casson W.Dorland E. Fable T. Görler F. Jenko D. Told A. Peeters L. Villard
Verification is the fundamental step that any turbulence simulation code has to be submitted in order to assess the proper implementation of the underlying equations. We have carried out a cross comparison of three flux tube gyrokinetic codes, GENE [F. Jenko et al., Phys. Plasmas 7, 1904 (2000)], GKW [A. G. Peeters et al., Comput. Phys. Commun. 180…
Preprint PublishedS. C. Guo Y. Q. Liu X. Y. Xu Z. R. Wang
Drift kinetic stabilization of the resistive wall mode (RWM) is computationally investigated using the MHD-kinetic hybrid code MARS-K, following the non-perturbative approach [Liu et al., Phys. Plasmas 15, 112503 (2008)], for both reversed field pinch (RFP) and tokamak plasmas. Various kinetic resonances between the mode and the guiding center drif…
Preprint Published