Improved numerical grid generation techniques for the B2 edge plasma code

Techniques used to generate grids for edge fluid codes such as B2 from numerically computed equilibria are discussed. Fully orthogonal, numerically derived grids closely resembling analytically prescribed meshes can be obtained. But, the details of the poloidal field can vary, yielding significantly different plasma parameters in the simulations. The magnitude of these differences is consistent with the predictions of an analytic model of the scrape-off layer. Both numerical and analytic grids are insensitive to changes in their defining parameters. Methods for implementing nonorthogonal boundaries in these meshes are also presented; they differ slightly from those required for fully orthogonal grids

Sawtooth effects in INTOR and TIBER

Transport simulations of the present designs for the INTOR and TIBER ignition devices predict that broad sawtooth oscillations will appear in these experiments. As was noted previously in studies of the Compact Ignition Tokamak, the primary effect of the oscillations is to reduce fusion power production on the average through profile flattening. Due to the disparate time scales for energy and current diffusion between sawtooth crashes, the simulations also produce peaked pressure profiles over a large low shear region inside the q = 1 surface (q is the safety factor). Pressure-driven modes will likely be unstable in this case. 5 figs., 2 tabs

Mini-Conference on the First Microns of the First Wall

Interactions between plasmas and their surrounding materials (plasma facing components) are of great interest to present and future magnetic fusion experiments, and ITER [ITER Physics Basis Editors, ITER Physics Exper Group Chairs, ITER Joint Central Team, and Physics Inte gration Unit, Nucl. Fusion 39, 2137 (1999)] in particular. This interest is the result of concerns with the survivability of these materials, as well as the impact of these interactions back on the plasma. These interactions begin on the surface, but can have consequences a few microns into the material.This mini-conference on these "first microns" was designed to bring to the Division of Plasma Physics Meeting experts on these topics who would otherwise not attend. At the same time, the mini-conference was intended to expose the broader fusion community to these issues. The mini-conference covered in three, half-day sessions the topics of lithium coatings and surfaces, mixed materials characteristics, and issues associated with graphite