Development of APS Synchrotron Instrumentation

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Cohen 9304725 Northwestern University, E.I. Du Pont de Nemours and Dow Chemical have formed a Collaborative Access Team, known as DUNU, and are proposing to instrument and operate a sector at the Advanced Photon Source. A funding schedule, with costs to be shared equally by both parties has been agreed upon, covering both a five year construction phase, as well as a ten year minimum operations phase. Currently DUNU employs three full-time senior scientists and engineers headquartered at Northwestern (a nationwide search is on for a fourth senior scientist), with extensive experience in beam line construction and operations both at the Cornell High Energy Synchrotron Source (CHESS) and the National Synchrotron Light Source (NSLS Brookhaven), plus management of one of the largest x-ray diffraction laboratories in the country. The purpose of this Collaborative Access Team is to carry out research on the structure of advanced materials. Our understanding of the structure (atomic to micron level) is a crucial prerequisite to the development of new materials with enhanced properties. Synchrotron radiation has become an essential tool in every aspect of structural analysis and has revolutionized many subfields of science and engineering. Many members of our CAT have been very active users of our national facilities. The vastly increased capabilities of "third generation" machines, such as the APS and similar storage rings in Europe and Japan, promise a second revolution. A broad research program has been formulated, involving currently more than 30 principal investigators from Du Pont and Northwestern. At least fifty other scientists and engineers, students and post-doctoral fellows will ultimately be involved. Although many fields of materials science and engineering are represented in this research program, the research to be supported by the instrumentation in this project has a particular focus: It deals with materials, whose intermediate scale structure (nanometer to micrometer) has a profound influence on their properties. Such materials are of immense technological importance and include precipitation-hardening alloys, ceramics, polymers, cement and composite materials. Many elements of this research program are totally beyond current capabilities at available x-ray sources (conventional and synchrotron). The instrumentation that we will develop depends heavily (or crucially) on the characteristics of the APS. It is grouped in two experimental stations, both utilizing undulator radiation: 1. General purpose scattering instrument, suitable for all types of diffraction experiments (amorphous, powder and single crystal work, surface and interface diffraction, standing waves etc.). Collimated beams (0.1-1 mm) and microbeams will be available for diffraction and microprobe work. The microbeam capability is of particular interest in the context of this proposal. 2. Small Angle X-ray Scattering microtomography instrument equipped with 2-D position sensitive detector and environmental chamber with multiple attachments (low and high temperature, UHV, sample changer). This may be the first x-ray instrument with sufficient imaging and scattering resolution to allow the two techniques to overlap in studying micron- sized structural features. We believe that DUNU possesses all the key ingredients of a productive and strong Collaborative Access Team. Northwestern University anchors an interactive research community through its interdisciplinary research centers (many of which, such as the Materials Research Center and the Center for Advanced CementBased Materials are supported by the National Science Foundation) and individual faculty research. E.I. Du Pont de Nemours & Co. brings its immense capabilities in scientific research and development. It is a world leader in process chemistry and engineering and t he manufacturing of high technology products. It is the intent of this collaboration not only to share a station at this major facility, but to develop interactive, collaborative research between the two institutions (we have installed a videoconferencing link to aid this interaction).