- SRC Research Spotlight: University of Illinois
- SRC Spring Open House—April 24
- Lightsources.org Launched
- SRC Scientific Director—Search Status
- New Beamline at SRC
- In Memoriam
1. SRC Research Spotlight: University of Illinois Condensed Matter Physics Group
Led by Dr. Tai-Chang Chiang, a subset of the Condensed Matter Physics Group at the University of Illinois at Urbana-Champaign is a regular fixture at SRC. This group maintains an ongoing presence via a constant stream of graduate students and post-docs who collaborate with a full-time resident of SRC, Dr. Tom Miller, a researcher and faculty associate of the Condensed Matter Physics Group at University of Illinois.
The group’s research focus at SRC includes the production and analysis of very thin films. As Dr. Chiang explains, just as a snowflake is much different than a snowball—although made of the same material—thin films exhibit different traits than their more massive cousins.
“In our research at SRC, we measure the electronic structure of films. Essentially all physical properties of materials are determined by their electronic structure. Due to quantum confinement and boundary effects, thin film electronic structure can be very different from the bulk counterpart, and likewise the properties can be substantially different and possibly useful,” Chiang explains.
Indeed, it’s this ability to reduce materials down to a few molecules of thickness—along with making the films as smooth as possible—that is the group’s goal. “In some ways what we’re trying to get is the simplest possible sample,” explains Miller. “So in a way we’re trying to get the most boring sample possible.”
Yet for several years the group’s progress has been anything but boring. In fact, Chiang and his colleagues have been exceptionally successful, with numerous publications resulting from the work of graduate students, post-doctoral researchers, and others at SRC. Still, while the work is deeply rooted in the fundamental exploration of physical properties, there are many exciting practical benefits to this research. Additionally, Chiang highlights his group’s history with SRC and why the facility is critical to the success of his research.
“Our work on atomically uniform films provides a fundamental understanding of the relationship between structure and properties based on quantum physics. Ultrathin films are important components for devices, now and future,” says Chiang. “Our work on quantum well states began in the 1980's at SRC. The first report of quantum well states as observed by angle-resolved photoemission appeared in 1986. My group discovered in 1998 that atomically uniform films of Ag can be prepared on Fe. In 2004, we reported that atomically uniform films of Pb and Ag can be prepared on Si and Ge. Si and Ge are the most important electronic substrate materials. The work has potential for great impact on future electronic devices. Angle-resolved photoemission is the best (and only) technique for mapping electronic structure, and SRC is an ideal place for carrying out such work.”
2. SRC Spring Open House
The SRC Open House is planned for Sunday, April 24th, from 12:00 – 5:00 p.m. The Open House provides the general public the opportunity to learn about the SRC and interact with SRC staff and Users. The last SRC open house was held on Sunday, September 14th, 2003, with close to 200 people attending the event.
For more information on this year’s Open House please contact the SRC Education & Outreach Coordinator, Chris Moore, at (608) 877-2137 or firstname.lastname@example.org.
3. Lightsources.org Launched!
February marked the launch of Lightsources.org, which quickly established itself as the premiere online location for information about light-sources facilities worldwide—with SRC as a founding member. As stated at the site, it seeks to be a “clearing house for light-source-related news, educational material, and user-related information and is updated daily. It provides links to current light-source news from the world's press, high-resolution photos and graphics from light-source facilities around the world, links to education and outreach programs, information about science policy and funding, a conference calendar, and important facility-related information for light-source Users.”
For a site that is less than a month old, it is very comprehensive and offers a wealth of up-to-date information for researchers and others interested in the latest news on lightsource-related research. In fact, the home page is centered by a listing of recent press releases from various publications reporting on light-sources research news. And, those interested can subscribe to News Flash, the email newsletter for lightsource.org.
Visitors to the site will find links to other research facilities worldwide as well as announcements for upcoming meetings. There are also links to numerous technical publications devoted to lightsources research and a section to assist in finding resources such as software, databases, catalogs, and more.
4. SRC Scientific Director—Search Status
The response to the search for a new SRC Scientific Director yielded several very strong candidates. Of these, three exceptional individuals were narrowed down from the field and they will each visit SRC and the University during early spring.
5. New Beamline at SRC
Construction of the varied-line-spacing plane grating monochromator (VLS-PGM) on port 041 at SRC was completed in December 2004. This joins the EUV and Wadsworth beamlines already using the permanent magnet undulator in long straight section two as a source. The beamline sports a broad energy range from 70 to 2000 eV using three gratings. It provides high throughput with moderate resolution (1000-3000 resolving power) and a small final spot size with a FWHM of 25 µm vertical and 70 µm horizontal at a resolving power of ~1000. To reach the higher energies, the U2 undulator is used in wiggler-mode.
The beamline consists of just three optical elements. The first is an ellipsoidal mirror (M0), located 13.4 m from the source. It is followed by one of three plane variable-line-spacing gratings. The light focuses onto an exit slit and then an ellipsoidal refocusing mirror (M1) demagnifies and places the focus at the sample position.
Conditioning and testing of the beamline started in December 2004 and finished in February 2005. Commissioning data confirms the beamline is performing as predicted. The first test User, Dr. Gelsomina De Stasio, has moved the SPHINX (Spectromicroscope for PHotoelectron Imaging of Nanostructures with X-rays) microscope online and will be using the beamline until April.
The procurement of a one-meter undulator for EUV has been finalized. Installation between bending magnet 10 and 11 is scheduled for the end of the year. The new EUV line will supersede the current line on undulator two.
Note: The VLS-PGM grating chamber was made by the Physical Sciences Laboratory (PSL)
The American Physical Society 2005 Wilson Prize was awarded to Dr. Keith Randolph Symon, Ph.D. Symon, who served as the Acting Director of SRC from 1983-1985, devoted much of his career to the University of Wisconsin, and is a Distinguished Faculty Fellow of the Physics Department. The citation for the Wilson Prize states that the award honors Symon “For fundamental contributions to accelerator science including the FFAG concept and the invention of the RF phase manipulation technique that was essential to the success of the ISR and all subsequent hadron colliders.”
Joe Bisognano, executive director of SRC, was Elected Vice Chair of the American Physical Society Division of Physics of Beams. Bisognano will assume his role as vice-chair of the division at the May 2005 Particle Accelerator Conference. In 2007, he will become Chair of the division.
Dr. Franz J. Himpsel received a Homboldt Foundation ( Germany) research award in the area of Semiconductor Physics. Himpsel, whose research interests include solid state physics—including electrical, magnetic, and optical properties—will conduct research in Germany during the month of March, 2005.
7. In Memoriam—Thomas A. Carlson, Ph.D.
Dr. Thomas A. Carlson, long-time user and friend of SRC, died of complications related to cancer on December 15, 2004 at his home in Oak Ridge, Tennessee. He was 76 years old. Carlson was a pioneer in the field of electron spectroscopy and during his storied career published nearly 200 articles and a classic book in the field, “Photoelectron and Auger Spectroscopy” (1974). Retired since 1988, Carlson devoted much of his time to art and music, eventually showcasing his artwork in shows in the Oak Ridge area. A comprehensive obituary can be found the website of the Oakridger newspaper at oakridger.com (a short registration is required).