Ames
Laboratory, U.S. Department of Energy, Ames, Iowa Ames
Laboratory, U.S. Department of Energy, Ames, Iowa
Ames, Iowa -- The U.S. Department of Energy (DOE) has awarded the Midwest Universities Collaborative Access Team (MUCAT) $2.8 million to begin construction of a beamline at the Advanced Photon Source (APS).
The APS is a new synchrotron radiation facility at the Argonne National Laboratory near Chicago that is dedicated to the production of x-ray beams for research. Construction of the APS itself, which was also funded by the DOE, was completed this year.
MUCAT is one of 15 collaborative access teams developing beamlines at the APS. Led by the Ames Laboratory and Iowa State University (ISU), it includes the University of Missouri at Columbia, the Georgia Institute of Technology, Kent State University, SUNY at Stony Brook, Washington University, the University of Wisconsin at Madison, the University of Nebraska and Michigan State University.
Construction of the beamline will cost about $5 million. The $2.8 million DOE award rounds out contributions from member institutions and the National Science Foundation.
At the APS, positrons (the antimatter counterparts of electrons) that have been accelerated to nearly the speed of light circulate through a storage ring about a kilometer in circumference. Because the positrons follow a curved path, they emit electromagnetic radiation, called synchrotron radiation.
But the uniqueness of the APS lies in its use of special devices, known as undulators, placed in the straight sections of the storage ring that will produce the most brilliant x-ray beams in the world. The brilliance of the x-ray source will allow scientists to study smaller samples, more complex systems and faster reactions and processes than ever before.
Alan Goldman, a physicist at the DOE's Ames Laboratory at Iowa State University and the current director of MUCAT, stresses the versatility of this new research tool. "The wonderful thing about the APS," he says, "is that it has applications to a tremendous variety of research problems. It's an invaluable tool because it's very general; it's not just for physicists. For example, in our CAT we have some groups that are interested in investigating interplanetary dust and biological systems such as cell membranes."
Because of the research interests of the people on the team, however, the MUCAT beamline will initially be used to investigate the magnetic and surface properties of materials. Both topics make the most of the beam brilliance. For example, the brilliant beam will make it possible to study the growth of thin films in real time, a capability of particular interest to the semiconductor industry.
The beamline will be one of two in MUCAT's "sector" of the APS. The storage ring and experiment hall are divided into 35 sectors, each of which has two beamlines streaking off at a tangent to the ring. One beamline originates at a bending magnet, which produces a horizontal fan of radiation. The other beamline begins at the undulator, which produces a brighter and smaller spot.
According to Goldman, "the APS takes responsibility for everything on their side of the shield wall. Out in the experiment hall we end up with two holes in the wall, one for the bending magnet radiation and one for the undulator. Our job, as one of the CATs, is to construct the x-ray optics and experimental equipment on our side of the shield wall."
The $5 million will be used for construction of an undulator beamline, whose design was overseen by Doug Robinson, the project scientist and a physicist at ISU. Like the APS itself, the beamline is "very simple, very straightforward and very versatile," says Goldman.
Ames Lab is operated for the DOE by ISU. The Lab conducts research into various areas of national concern, including energy resources, high-performance computing, environmental cleanup and restoration, and synthesis and study of new materials.
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