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Project overview This Strategic Initiative (SI) will advance nondestructive characterization of mesoscale (millimeter-sized) objects-allowing micrometer resolution over the objects' entire volume. Xray imaging will be developed that allows object characterization with materials that vary widely in composition, density, and geometry.[Martz and Albrecht, 2004]

The mechanical design of the vacuum pumping systems for SNS (Spallation Neutron Source) DTL (Drift Tube Linac) and CCL (Coupled Cavity Linac) linac systems is summarized. Both vacuum systems were modeled to select the optimal pump configuration. The pressure history in up to 182 sub-volumes was analyzed in detail. Included in the model are time-dependent outgassing rates and pressure-dependent pump speeds for a variety of gas species. With this information, we solved for the pressure history during roughing and with turbo and ion pumps. The number and size of each pump were optimized to achieve the desired pressure with minimal costs. In the optimized design, directly mounted ion pumps were provided for six DTL tanks. For four CCL modules (each in length of 12-15 m), ion pumps with manifolds were selected. With all metallic surface outgassing, seal leakage and expected gas loads from all diagnostic devices taken into account, the designed systems can provide operating drift-tube pressure below 1.8x10 -7 Torr and CCL beamline pressures below 9.2x10 -8 Torr even under abnormal conditions. Details of the design and the modeling results are presented.

This paper uses group theory for enumeration of contacts between geometric elements necessary for kinematic registration or part referencing in robotics. The results are applied to type synthesis of tactile sensing mechanical fixtures. Kinematic registration is an important step in robot calibration and in data driven automation. Although the scope of the paper is limited to geometric contacts involving points, lines, planar surfaces, cylindrical surfaces, and spherical surfaces, the techniques developed are general and can be applied to other geometric features and non-tactile sensing elements used in robotic calibration and part referencing.