World's brightest x-ray source Advanced Photon Source will pioneer research in many fields Argonne National Laboratory's 7 GeV Advanced Photon Source, or APS. will use recently developed technology to produce the brightest beam of highenergy x-rays ever available for research - 10,000 times brighter than currently possible. This incredibly bright light will open new vistas of research in many fields of science and technology, including materials sciences, biology, medicine, biotechnology, chemistry, physics, and the geosciences. The APS will be available to researchers from the nation's academic. industrial, and government laboratories, who will gain access to the facility by submitting proposals or by joining consortia that own beam lines. Light is one of the most important analytical tools in the research arsenal. The brighter the light, the faster data can be gathered, and the greater the detail revealed. The APS x-ray beams will permit studies of materials as complex as modern alloys. events as fast as chemical reactions, and biological systems as vital as the beating human heart The APS has received strong support from the scientific community. In recent years, national advisory panels set up by the Department of Energy and the National Academy of Sciences (EisenbergerKnotek, 1984, Seitz-Eastman, 1984; Stehli, 1985. Brinkman. 1986. ERAB, 1987) have given the APS highest priorty among new materials research facilities. The APS will produce brilliant, narrow beams of xrays by accelerating positrons (particles like electrons, but positively charged) in a circular path at speeds near that of light. When the beam is bent by magnets, it emits energy in the form of x-rays. "Wigglers' and 'undulators' - recently developed devices based on modern magnet technology - will vibrate the particle path over a short distance. The result will be the most briliant beams of x-rays ever produced. As many as 100 beam lines will be available for research, approximately doubling the number of synchrotron x-ray beams available to the nation s researchers APS positrons will be accelerated to an energy of 7 billion electron-voits (7 GeV) and stored in a circulat ing ring The greater this energy the more focused The main APS building, where experiments will be The APS project achieved an important milestone in 1987 when its conceptual design report. prepared by Argonne scientists and engineers, passed with flying colors an exhaustive preconstruction review by DOE's Office of Energy Research. Construction will begin in 1989 and be completed in 1994. The APS will significantly enhance the nation's prominence in both basic and applied sciences, and will contribute greatly to expanding America's high-technology capabilities. The long-term scientific and economic benefits of the APS have been recognized in Europe and Japan, where similar machines are being built. History of x-ray sources 20 18 7 GeV Advanced Photon Source 16 2nd generation Logarithm of beam brilliance 14 1st generation synchrotron sources 12 10 X-ray tubes 8 Almost 100 years ago. W. D. Coolidge discovered the first x-ray tube X-rays have proven to be a powerful tool in research, industry, and medicine Since the early 1960s. rapid advances have been made in the briance of x-ray beams for research. First generation synchrotron Sources were electron accelerators from which materials scientists used parastic beams" of x-rays Second generation synchrotron sources were but expressly to provide x-rays for matenais research. The 7 GeV Advanced Photon Source, a third generation source. will provide beams 10.000 times more brilliant than those from previous machines. 6 materialssciencest biology me Materials science Revolution in materials science possible with APS The 7 Gev Advanced Photon Source at Argonne will generate a materials science and engineering revolution that will help ensure the economic prosperity of U S. industry through the next century. Crucial to technological progress is the invention of new materials with improved properties Just as the Industrial Revolution was made possible by the invention of steel, future technological revolutions will be made possible by the invention of improved semiconductors. polymers, ceramics, superconductors, magnetic composites, metallic glasses, and artificially layered structures. These materials will find key applications in fields such as computing, microminiaturization robotics, space exploration, communications, manufacturing. and many energy technologies The brilliant beams of x-rays produced by the APS will provide the most sophisticated tools ever available for scientists to understand the behavior of new materials and the processes by which they are formed The tremendous brilliance of APS x-rays can reveal the precise positions of atoms as new materials are formed, and the mechanism by which these positions give materials new and unusual properties. This knowledge will not only help form the basis for theoretical models of these materials, but also will help create other new materials with properties tailored to specific applications. In addition, research at the APS will provide a wealth of information about the magnetic and electronic structure of new materials, information that is essential to understanding their usefulness in advanced technologies Studies of metallic glasses provide an example of the kind of information the APS can provide These materials which are produced when molten metals solidify rapidly, are thousands of times stronger than materials used in present-day technologies Their unusual strength is related to the 'tangled' arrangement of their atoms This arrangement follows patterns which are not yet fully understood The APS will enable scientists to focus on this atomic detail and relate its tangled structure to its enhanced strength. Scientists will use this knowledge to predict structures of even stronger new materials. A second example is provided by ceramics Ceramic fibers are already being used for short-range information transmission, and ceramic mirrors have been designed for telescopes in future space shuttles. Recently, new ceramics have been discovered that lose all resistance to electricity at 90 degrees Kelvin. These superconductors promise exciting new technologies in such fields as electronics, power transmission. and transportation. The promise of ceramics is great enough that 7 GeV Advanced Photon Source 10 1 101 102 10 Momentum (Å11) 105 104 10 102 10 Space (Microns) 10 1 10' 102 103 Energy (eV) 10 10' 10 105 104 10 Time (Picoseconds) New frontiers to open 3 New Research Frontiers in condensed matter research Developments in condensed matter physics have been stimulated by the demand for new materials with improved properties Condensed matter embodies in its conceptual framework four physical quantities-energy, momentum time, and space Higher resolution in the measurement of these four fundamental parameters is expected from the ultra-high brilliance, collimation time structure, and tunability of x-rays from Argonne's APS Major advances In understanding condensed matter physics are expected to result. Many areas of condensed-matter research will benefit from the APS A few examples that have excited the imaginations of condensed matter physicists are dynamic excitations with thermal energies, nuclear-resonance Bragg scattering, magnetic scattering from monolayers, two-dimensional melting, wetting phenomena, and substrate and interface interactions |