A 2-4 keV Multi-Layer Mirrored Channel for the NIF Dante system
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Physics - Plasma physics↗
Engineering topics
Wright, J
Publications and source records attributed to Wright, J.
Multi-scale mechanics of granular solids from grain-resolved X-ray measurements
This work discusses an experimental technique for studying the mechanics of three-dimensional (3D) granular solids. The approach combines 3D X-ray diffraction and X-ray computed tomography to measure grain-resolved strains, kinematics and contact fabric in the bulk of a granular solid, from which continuum strains, grain stresses, interparticle forces and coarse-grained elasto-plastic moduli can be determined. We demonstrate the experimental approach and analysis of selected results on a sample of 1099 stiff, frictional grains undergoing multiple uniaxial compression cycles. We investigate the inter-particle force network, elasto-plastic moduli and associated length scales, reversibility of mechanical responses during cyclic loading, the statistics of microscopic responses and microstructure–property relationships. This work serves to highlight both the fundamental insight into granular mechanics that is furnished by combined X-ray measurements and describes future directions in the field of granular materials that can be pursued with such approaches.
36 MATERIALS SCIENCE↗
Force Measurements in Stiff, 3D, Opaque Granular Materials
Abstract not provided
36 MATERIALS SCIENCE↗
Improving Sensitivity in the NNSS COMPASS Model
The Comprehensive Analysis of Safeguards Strategies model, COMPASS, was initially implemented with the goal of eliminating functions and requirements that did not contribute to the MC&A program at the particular site. The model sub-elements were revised several times through additions and deletions as the process was better understood. Contributions and ratings were developed and implemented. Because of the original intent, the process left the contribution factors closely grouped toward the top of the range. The effect of this is a flat sensitivity; a change in any element and sub-element affected the system effectiveness to the same degree no matter which one changed. This paper describes a method for determining element and sub-element contributions so that changes in element effectiveness are more accurately reflected in the overall system effectiveness.
98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗