H. Smith P. Helander L.-G. Eriksson D. Anderson M. Lisak F. Andersson
After the thermal quench of a tokamak disruption, the plasma current decays and is partly replaced by runaway electrons. A quantitative theory of this process is presented, where the evolution of the toroidal electric field and the plasma current is calculated self-consistently. In large tokamaks most runaways are produced by the secondary avalanch…
PublishedI.T. Chapman S. Saarelma T.C. Hender S.E. Sharapov G.T.A. Huysmans A.B. Mikhailovskii H. Meyer A. Kirk H.R. Wilson
Present day tokamaks are capable of generating toroidal flows approaching the ion sound speed. Such toroidal rotation is known to have a stabilising effect on resistive wall modes[1]. Here the effects of plasma rotation and diamagnetic drifts on the n = 1 internal kink mode and high n ballooning modes are presented with specific comparison to exper…
PublishedP. Helander T. Fülöp M. Lisak
It is shown that poloidally asymmetric particle transport or fueling in a tokamak generally produces an electric current parallel to the magnetic field, in particular if the transport or fueling is up-down asymmetric. For instance, a current arises in the edge region if most particle transport across the last closed flux surface occurs in the midpl…
PublishedChr. Day D. Brennan P. Camp H.S. Jensen G. Jones A. Mack A. Miller
A cryosorption panel test arrangement was installed in the Cryogenic Forevacuum (CF) Subsystem of the Active Gas Handling System (AGHS) at JET. The pump panels were of ITER relevant design in terms of geometry and dimension, coating and sorbent material. The central objective of this investigation was to study, for the first time in such an in-dept…
PublishedK. Kohary V. M. Burlakov D. G. Pettifor
The structure of amorphous In x Se y alloys has been studied by a first principles tight-binding molecular dynamics technique. The three-dimensional amorphous structures with different densities at different compositions were prepared by quick quenching from the liquid phase. The characteristics of short-range order, namely radial distribution func…
PublishedStacy E. Snyder Arnold H. Kritz Glenn Bateman Thawatchai Onjun Vassili Parail EFDA JET Contributors
Simulations of Joint European Torus (JET) [P. H. Rebut and et al. , Nucl. Fusion 25 , 1011 (1985)] type I high-mode H-mode discharges with edge localized modes ELMs are used to study the effect of isotope mass on the height of the pedestal and the frequency of ELMs. A dynamic model for the H-mode pedestal and ELM cycles is employed in the JETTO int…
PublishedG. A. Cottrell R. Pampin N. P. Taylor
We present calculations of the transmutation of initially pure tungsten first-wall and divertor plasma-facing armor intoW-Re-Os alloys in the European Union Power Plant Conceptual Study (PPCS) fusion plant models A, B, and AB. The fusion neutron spectrum was modeled using the MCNP Monte Carlo code including resonance self-shielding effects, and we …
PublishedRalf Drautz Dewey A. Murdick Duc Nguyen-Manh Xiaowang Zhou Haydn N. G. Wadley David G. Pettifor
An analytic interatomic bond-order potential BOP is derived that depends explicitly on the group number of the sp -valent element. This is achieved by generalizing the previously published BOP for group-IV elements by extrapolating from half-full occupancy using a simple envelope function for the upper bound of the bond order. This interatomic pote…
PublishedC. N. Lashmore-Davies A. Thyagaraja D. R. Mccarthy
The mechanism of four nonlinearly interacting drift or Rossby waves is used as the basic process underlying the turbulent evolution of both the Charney-Hasegawa-Mima-equation CHME and its generalized modification GCHME. Hasegawa and Kodama’s concept of equivalent action or quanta is applied to the four-wave system and shown to control the distrib…
PublishedJ. Preinhaelter G. Taylor V. Shevchenko J. Urban M. Valovic P. Pavlo L. Vahala G. Vahala
The interpretation of EBW emission from spherical tokamaks is nontrivial. We report on a 3D simulation model of this process that incorporates Gaussian beams for the antenna, a full wave solution of EBW-X and EBW-X-O conversions using adaptive finite elements, and EBW ray tracing to determine the radiative temperature. This model is then used to in…
Published