Y. Liang H. R. Koslowski P. R. Thomas E. Nardon B. Alper P. Andrew Y. Andrew G. Arnoux Y. Baranov M. Bécoulet M. Beurskens T. Biewer M. Bigi K. Crombe E. De La Luna P. De Vries W. Fundamenski S. Gerasimov C. Giroud M. P. Gryaznevich N.
Type-I edge-localized modes (ELMs) have been mitigated at the JET tokamak using a static external n 1 perturbation field generated by four error field correction coils located far from the plasma. During the application of the n 1 field the ELM frequency increased by a factor of 4 and the amplitude of the D signal decreased. The energy loss per ELM…
PublishedM. K. Lilley S. E. Sharapov
A discrete spectrum of compressional Alfvén eigenmodes and ion-ion hybrid eigenmodes is found to exist above the tritium ion cyclotron frequency in the deuterium-tritium D-T plasma of a spherical tokamak power plant STPP [H. R. Wilson and et al. , 19th IAEA Fusion Energy Conference IAEA, Lyon, France, (2002), No. FT/1-4]. An equilibrium magnetic w…
PublishedP. M. Derlet D. Nguyen-Manh S. L. Dudarev
We investigate the structure and mobility of single self-interstitial atom and vacancy defects in bodycentered- cubic transition metals forming groups 5B vanadium, niobium, and tantalum and 6B chromium, molybdenum, and tungsten of the Periodic Table. Density-functional calculations show that in all these metals the axially symmetric 111 self-inters…
PublishedChristian 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…
PublishedM. J. Cawkwell D. Nguyen-Manh D. G. Pettifor V. Vitek
A tight-binding based bond-order potential BOP has been constructed for the fcc transition metal iridium that includes explicitly only d orbitals in the evaluation of the total energy.We show that hybridization between the nearly free electron sp band and the unsaturated covalently bonded d orbitals is important in determining the relative stabilit…
PublishedD. C. Mcdonald Y. Andrew G. T. A. Huysmans A. Loarte J. Ongena J. Rapp S. Saarelma
A wide range of studies on JET have contributed greatly to the development of the ELMy H-mode as a high-performance scenario for fusion devices and to the understanding of the physical processes that underlie it. Development has focused on the production of a highperformance, high-density, stationary scenario suited to deuterium-tritium operation a…
PublishedElizabeth Surrey
A model of the space charge neutralization of negative ion beams, developed from the model due to Holmes, is applied to the ITER heating and diagnostic beams. The Holmes model assumed that the plasma electron temperature was derived from the stripped electrons. This is shown to be incorrect for the ITER beams and the plasma electron temperature is …
PublishedB. Crowley D. Homfray U. Fantz D. Boilson R.S. Hemsworth
Determining d 2 I/dV 2 from a traditional Langmuir probe trace using numerical techniques is inherently noisy and generally yields poor results. We have developed a Langmuir probe system based on a method first used in the 1950's by Boyd and Twiddy [1]. The system measures the 2nd derivative directly. This paper presents results from the d…
PublishedC. G. Gimblett R. J. Hastie P. Helander
Edge-localized modes (ELMs) are cyclic disturbances in the outer region of tokamak plasmas that are influential in determining present and future tokamak performance. In this Letter, we outline an approach to modeling ELMs in which we envisage toroidal peeling modes initiating a Taylor relaxation [Phys. Rev. Lett. 33 , 1139 (1974)] of a tokamak out…
Published