Andrew Davis Andrew Turner
It is known that a priori information on the distribution of neutron fluxes over neutron transport models can improve the computational efficiency of Monte Carlo transport calculations via the use of variance reduction techniques. The uncertainty lies in finding a method which obtains this information as fast and effortlessly as possible. A number …
PublishedK. G. McClements M. J. Hole
The effects of poloidal and toroidal flows on tokamak plasma equilibria are examined in the magnetohydrodynamic limit. “Transonic” poloidal flows of the order of the sound speed multiplied by the ratio of poloidal magnetic field to total field can cause the normally elliptic Grad– Shafranov GS equation to become hyperbolic in part of the solu…
PublishedPui-Wai Ma C. H. Woo
We develop a dynamical simulation model for magnetic iron where atoms are treated as classical particles with intrinsic spins. The atoms interact via scalar many-body forces as well as via spin orientation dependent forces of the Heisenberg form. The coupling between the lattice and spin degrees of freedom is described by a coordinate-dependent exc…
PublishedO. E. Garcia N. H. Bian W. Fundamenski
Radial convection of isolated filamentary structures due to interchange motions in magnetized plasmas is investigated. Following a basic discussion of vorticity generation, ballooning, and the role of sheaths, a two-field interchange model is studied by means of numerical simulations on a biperiodic domain perpendicular to the magnetic field. It is…
PublishedM. F. F. Nave H. R. Koslowski S. Coda J. Graves M. Brix R. Buttery C. Challis C. Giroud M. Stamp P. De Vries Jet-Feda Contributors
During a recent reversed toroidal field (B T) campaign at the Joint European Torus (JET), experiments were performed to investigate the effect on sawteeth of neutral beam injection (NBI)-driven toroidal plasma rotation counter to the direction of the toroidal plasma current and B T . A power scan at constant density has permitted analytical continu…
PublishedS. V. Annibaldi G. Manfredi R. O. Dendy
The transport of test particle ensembles moving in turbulent electrostatic fields governed by the Hasegawa–Mima equation is investigated. It ranges from subdiffusive to ballistic, depending on the size (in terms of thermal ion Larmor radii) of the domain considered, and on the magnitude of the background density gradient. In addition to the elect…
Published