S.A. Sabbagh J.W. Berkery A. Kirk Y.S. Park J.H. Ahn J.M. Bialek Y. Jiang J.D. Riquezes J.G. Bak K. Erickson A.H. Glasser C. Ham J. Hollocombe J. Kim J. Ko W.H. Ko L. Kogan J.H. Lee A. Thornton S.W. Yoon Z.R. Wang
Disruption prediction and avoidance is critical in ITER and reactor-scale tokamaks to maintain steady plasma operation and to avoid damage to device components. The present status and results from the physics-based disruption event characterization and forecasting (DECAF) research effort are shown for multiple tokamak devices. Present analysis of K…Preprint Published
S.A. Sabbagh J.W. Berkery Y.S. Park J.H. Ahn Y. Jiang J.D. Riquezes J.G. Bak R.E. Bell M.D. Boyer L. Delgado-Aparicio A.H. Glasser J. Hollocombe J. Kim A. Kirk J. Ko W. Ko L. Kogan B.P. LeBlanc J.H. Lee C.E. Myers L. Terzolo A. Thornton S.W. Yoon
Disruption prediction and avoidance is a critical need for next-step tokamaks such as ITER. The Disruption Event Characterization and Forecasting Code (DECAF) is used to fully automate analysis of tokamak data to determine chains of events that lead to disruptions and to forecast their evolution allowing sufficient time for mitigation or full av…Preprint
Christian Lang Se Ahn Song Duc Nguyen Manh David J. H. Cockayne
The structural changes during the phase change between the amorphous and crystalline phase in Ge 2 Sb 2 Te 5 have been the subject of intense study due to the importance of Ge 2 Sb 2 Te 5 in phase change memory devices. In our study, the energetics of the transition between the crystalline and the amorphous phase of Ge 2 Sb 2 Te 5 is explored using…Published
P. Helander R. J. Akers L.-G. Eriksson
It is well known that when neutral beams inject ions into trapped orbits in a tokamak, the transfer of momentum between the beam and the plasma occurs through the torque exerted by a radial return current. It is shown that this implies that the angular momentum transferred to the plasma can be larger than the angular momentum of the beam, if the in…Published
G. Y. Antar G. Counsell J.-W. Ahn
This article is dedicated to the characterization of turbulent transport in the scrape-off layer of the Mega Ampere Spherical Tokamak [A. Sykes and et al. , Phys. Plasmas 8 , 2101 (2001)] as a function of the average density n L . The aim is to answer a renewed interest in this subject since the bursty character of turbulence in the scrape-off laye…Published
G. Y. Antar G. Counsell J.-W. Ahn Y. Yang M. Price A. Tabasso A. Kirk
Recently, it was shown that intermittency observed in magnetic fusion devices is caused by large-scales events with high radial velocity reaching about 1/10th of the sound speed s called avaloids or blobs [G. Antar and et al. , Phys. Rev. Lett. 87 065001 (2001)]. In the present paper, the poloidal distribution of turbulence is investigated on the M…Published
R. J. Akers J. W. Ahn L. C. Appel E. R. Arends K. B. Axon et al.
Spontaneous transitions from the low ‘‘L-mode’’ to high ‘‘H-mode’’ of tokamak plasma confinement, first observed during neutral beam heating experiments on ASDEX, are now routinely achieved in many tokamak experiments. The H-mode regime is attractive as it offers the possibility of enhanced confinement, and thus a route towards a mo…Published
A. Sykes J.-W. Ahn R. Akers E. Arends P. G. Carolan et al.
First physics results are presented from MAST (Mega-Amp Spherical Tokamak), one of the new generation of purpose built spherical tokamaks (STs) now commencing operation. Some of these results demonstrate, for the first time, the novel effects of low aspect ratio, for example, the enhancement of resistivity due to neo-classical effects. H-mode is ac…Published