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http://pac07.org/proceedings/PAPERS/TUPMS045.PDF
SRC stuff logo of the Synchrotron Radiation Center, Madison.gif|200px
| [[]] | |
| Motto | Illuminating the path to scientific discovery |
|---|---|
| Established | 1968 |
| Research type | Synchrotron light source |
| Location | Stoughton, Wisconsin |
Operating agency | University of Wisconsin-Madison |
| Website | http://www.src.wisc.edu/ |
Tantalus!
History
The Road to the SRC: 1953 to 1968
In 1953 15 universities formed the Midwest Universities Research Association (MURA) to promote and design a high energy proton synchrotron, to be built in the Midwest. With the intent of constructing a large accelerator, MURA purchased a suitable area of land with an underlying flat limestone base near Stoughton, Wisconsin, about 10 miles from the Madison campus of the University of Wisconsin. A small electron storage ring, operating at 240 Mev, was designed as a test facility to study high currents, and construction of this ring started in 1965. However, in 1963 President Johnson had decided that the next large accelerator facility would not be built at the MURA site, but in Batavia, Illinois - this became Fermilab. In 1967 MURA dissolved with the storage ring incomplete and with no further funding.
In 1966 a subcommittee of the National Research Council, which had been investigating the properties of synchrotron radiation from the 240 MeV ring, recommended it be completed as a tool for spectroscopy. A successful proposal was made to the US Air Force Office of Scientific Research, and the ring was completed in 1968, administered by the University of Wisconsin. [1] For two decades Tantalus produced hundreds of experiments and was a testing ground for many of the synchrotron techniques used today. Its administrative home, the University of Wisconsin Synchrotron Radiation Center, was located in a bucolic environment more than 13 miles from the Madison campus. The relative isolation facilitated strong bonds among users. The SRC’s annual users meeting became an important event; figure 3 pictures Brown and Rowe at one of the first gatherings, around 1969. Today’s dedicated synchrotron facilities can be as large as a city block. But Tantalus was no bigger than a dinner table, and its small building, even after a substantial expansion in 1972, was incredibly crowded with equipment and researchers. Users worked in very close quarters. The close proximity made cross fertilization of ideas unavoidable. The atmosphere was open, friendly, informal, and exciting. It was not particularly comfortable physically, though. For one thing, the system that heated the control room did not work in an adjoining washroom. So, to avoid frozen pipes, users just left the door wide open. After someone posted a sign alerting users to the policy, an international contest began, with each person translating the message into his own language. Acopy of the cosmopolitan sign, shown in figure 4, eventually became part of an NSF funding request as evidence of Tantalus’s growing international impact. That impact was truly remarkable. After struggling with synchrotrons, users came from many countries to discover in Tantalus an easy-to-use light source. Research during those early years was dominated by optical spectroscopy of atoms, molecules, and solids. The broad band of available wavelengthswavelengths made that a good choice. The photon energies reached the core-level thresholds in many materials and allowed researchers to investigate a wealth of phenomena, most notably electron-correlation effects. Moreover, Tantalus brought a new dimension to optical experiments. For example, it supported thermomodulation and electromodulation studies of solids,9 and thereby expanded the scope of modulation spectroscopy, a leading field at that time. By using, say, an oscillating electric or thermal field to perturb a semiconductor, researchers could extract hidden features from the optical spectra. The approach solved important issues about the band structure of gallium arsenide and other materials. In the mid-1970s the center of gravity at Tantalus gradually shifted toward photoemission experiments, thanks largely to a steady improvement of the emitted intensity, which increased with the beam current circulating in the ring. The initial Tantalus injector was the old FFAG synchrotron; only one electron bunch was injected in the ring, which yielded a current between 1 and 2 mA—three orders of magnitude below what can be achieved today. The advent of multiple bunches in 1973 increased the current to 50 mA. Injection of electrons using a 40-meV accelerator known as a microtron in 1974 pushed current levels still higher—to 150 mA in 1974 and to an amazing 260 mA in 1977. In 1971 Dean Eastman and Warren Grobman of IBM produced the first photoelectron spectra using Tantalus (see figure 5), a result that revealed momentum conserved in photoemission and changes in the lineshape of gold with photon energy.10 The demonstration was a milestone in the development of photoemission as a research tool. The tunability of synchrotron light allowed researchers to disentangle a material’s ground-state electronic properties—their main objective—from its final-states effects, transition probabilities, and other factors.Between 1974 and 1975, Tantalus reached an intensity level sufficient for angle-resolved photoemission. A joint Bell Labs–Montana team led by Neville Smith, Morton Traum, and Lapeyre conducted the earliest experiments.13 Figure 6 illustrates the impressive first results: The angular intensity patterns revealed the crystal symmetry of a layered compound. As an experimental technique, angle-resolved photoemission developed rapidly and had an important conceptual impact on condensed-matter physics.in gas-phase spectroscopy was yet another pillar of success at SRC, starting from the early absorption studies of noble gases14 and silane.15 Throughout the 1970s and early 1980s, Thomas Carlson and Manfred Krause of Oak Ridge National Laboratory and others produced important results on Tantalus concerning auto-ionization, shape resonances, Cooper minima, and several other phenomena.16 James Taylor’s team from the University of Wisconsin– Madison inaugurated gas-phase photoemission in 1972.17 The results of their studies revealed strong photon-energy effects that required, for example, a careful reanalysis of previous benzene data. The SRC produced more than a flow of experimental results. It was also the source of advanced optical instrumentation such as focusing devices and monochromators. In 1973 Ed Rowe, Mills, and Walter Trzeciak even tested insertion devices, arrays of magnets that produce highly collimated and very intense beams of light by transversely “wiggling” the electrons passing through them. The cases discussed here are merely a fra [2]
Tantalus: 1968-1985
With the new Aladdin storage ring operating, Tantalus was officially decommissioned in 1987, although it was run for six weeks in the summer of 1988 for experiments in atomic and molecular fluorescence. The storage ring was disassembled in 1995, and half the ring, the RF cavity and one of the original beamlines are now in storage at the Smithsonian Institution.[1]
Aladdin: 1985
Since 2010
funding problems [7]
Notable Science
G. J. Lapeyre award
In 1973 the vault that held Tantalus was being enlarged, and during a facility picnic a rainstorm hit and caused the vault to start to flood. Jerry Lapeyre of Montana State University used the lab's tractor to build earthworks to divert the water. His efforts led then-director Rowe to create the annual G. J. Lapeyre award to be awarded to “one who met and overcame the greatest obstacle in the pursuit of their research”. The trophy has an octagonal base representing Tantalus, with a beer can from the lab picnic which preceded the flood, topped by a concrete “raindrop”.[8]
The Canadian Synchrotron Radiation Facility
Notable Science
Educational Outreach
Technical description
Beamlines
| Name | Port assigned[9] | Source | Energy range (eV unless stated) | Usage |
|---|---|---|---|---|
| 10m TGM | 123 | |||
| 4m NIM | 081 | |||
| 6m TGM | 042 | |||
| Ames-Montana ERG-Seya | 053 | |||
| DCM | 093 | |||
| HERMON | 033 | 62-1400 | ||
| Infrared | 031 | Bending magnet | 650-8000 | Infrared spectromicroscopy |
| IRENI | 02 | Bending magnet | 850-5500 | Infrared spectromicroscopy |
| Mark V Grasshopper | 043 | |||
| PGM undulator on U3 | 071 | |||
| Stainless Steel Seya | 051 | |||
| U2 VLS-PGM | 041 | |||
| U2 Wadsworth | 041 | 7.8-40 | ||
| U9 VLS-PGM | 091 | |||
| Undulator4m NIM on U1 VLS-PGM | 011 | |||
| White light | 061 |
- ^ a b c Lynch, D. W. (1997). "Tantalus, a 240 MeV Dedicated Source of Synchrotron Radiation, 1968-1986". Journal of Synchrotron Radiation. 4: 334–343. doi:10.1107/S0909049597011758. Cite error: The named reference "Tant" was defined multiple times with different content (see the help page).
- ^ Margaritondo, Giorgio (2008). "The evolution of a dedicated synchrotron light source". Physics Today. 61: 37–43. doi:10.1063/1.2930734.
- ^ Green, Michael A.; Huber, David L.; Rowe, Ednor M.; Tonner, Brian (1991). "The Synchrotron Radiation Center of the University of Wisconsin-Madison". Review of Scientific Instruments. 63: 1582–1583. doi:10.1063/1.1142981.
- ^ Moore, C. J.; Altmann, K. N.; Bisognano, J. J.; Bosch, R. A.; Eisert, D.; Fischer, M.; Green, M. A.; Hansen, R. W. C.; Himpsel, F. J.; Hochst, H. (2002). "Current status of the Synchrotron Radiation Center". Review of Scientific Instruments. 73: 1677–1679. doi:10.1063/1.1425390.
- ^ Kinraide, r.; Moore, C. J.; Jacobs, K. D.; Severson, M.; Bissen, M. J.; Frazer, M.; Bisognano, J. J.; Bosch, R. A.; Eisert, D.; Fischer, M. (2004). "Current Status of the Synchrotron Radiation Center". AIP Conference Proceedings. 705: 105–112. doi:10.1063/1.1757746.
- ^ Rowe, Ednor M. (1980). "The Aladdin electron storage ring". Annals of the New York Academy of Sciences. 342: 334–343. doi:10.1111/j.1749-6632.1980.tb47205.x.
- ^ Reich, Eugenie Samuel (2011). "US physics feels the squeeze". Nature. 471: 278. doi:10.1038/471278a.
- ^ Lapeyre, Gerald J. (1994). "Development of synchrotron radiation photoemission from photoionization to electron holography". Nuclear Instruments and Methods A. 347: 17–30. doi:10.1016/0168-9002(94)91848-1.
- ^ "Beamline Specifications". Retrieved 2012-07-30.