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Most scientific imaging applications of CCDs require low noise and high charge transfer efficiency. These attributes have been exhibited in devices produced by a number of manufacturers, but not all perform well as x -ray imaging spectrometers. This application requires that all charge liberated by anx -ray photon be completely collected within the original pixel. Processes of charge diffusion may prevent this from occurring and degrade the obtainable energy resolution. Measurements of charge diffusion and its effect on x -ray performance are presented for three types of English Electric Valve Co. (EEV) CCDs. These are fabricated on bulk and epitaxial wafers with resistivities of 1000 and 10 II cm. A range of different pixel sizes is employed. Measurements of detection efficiency are compared with predictions of a theoretical chargediffusion model. Implications for optimizing the CCD structure for use in anx -ray astronomical spectroscopy application are noted.

The unmanned ground combat vehicle (UGCV) design evolved by the SAIC team on the DARPA UGCV Program is summarized in this paper. This UGCV design provides exceptional performance against all of the program metrics and incorporates key attributes essential for high performance robotic combat vehicles. This performance includes protection against 7.62 mm threats, C130 and CH47 transportability, and the ability to accept several relevant weapons payloads, as well as advanced sensors and perception algorithms evolving from the PerceptOR program. The UGCV design incorporates a combination of technologies and design features, carefully selected through detailed trade studies, which provide optimum performance against mobility, payload, and endurance goals without sacrificing transportability, survivability, or life cycle cost. The design was optimized to maximize performance against all Category I metrics. In each case, the performance of this design was validated with detailed simulations, indicating that the vehicle exceeded the Category I metrics. Mobility metrics were analyzed using high fidelity VisualNastran vehicle models, which incorporate the suspension control algorithms and controller cycles times. DADS/Easy 5 3-D models and ADAMS simulations were also used to validate vehicle dynamics and control algorithms during obstacle negotiation.