ALS Holds Workshop to Advance Scientific and User Programs

April 3, 1998

By Lynn Yarris, [email protected]

"Where is the forefront of your disciplines?" was the question with which Pat Dehmer, associate director of DOE's Office of Basic Energy Sciences (BES), challenged the 325 scientists who had come for last week's "Workshop on Scientific Directions at the Advanced Light Source." Meeting in eight separate "working group" sessions, leaders from around the world in the use of synchrotron radiation thrashed out answers to Dehmer's challenge, then determined how the ALS could be used to advance those forefronts. The results, said Berkeley Lab director Charles Shank, were "historic."

From March 23-25, workshop attendees grappled with issues in a wide range of disciplines where the exceptional brightness and coherence of ALS x-rays and ultraviolet light might play a critical role. The eight working group sessions were organized under the headings of strongly correlated materials; nanostructures/ semiconductors; environmental and Earth sciences; polymers and soft matter; biosciences; catalytic material/surface sciences; magnetic materials; atomic, molecular, and optical physics/chemical dynamics. In each case, the conclusion was that the ALS is the right machine at the right time.

"This workshop began rather modestly but expanded in scope as the registration grew," Dehmer said. "With the quality of the working group session reports, we have also increased our expectations." She commended the working group session reports as being impressive enough that they will be submitted to an appropriate scientific journal for publication.

From the workshop's outset, Director Shank made it clear that the purpose of the working group sessions was to make "the most compelling case possible" for the ALS' scientific program. In his address to the opening plenary session, Shank charged the groups to determine the "exciting scientific issues, the role of the ALS, and what specific tools are needed." He also emphasized that without a compelling scientific case, the ALS would not be able to "command the resources it needs."

The critical link between strong, cutting-edge science and budgetary support from Washington was later reiterated by Iran Thomas, who heads BES' materials science division, a primary source of ALS funding.

"Scientific proposals must be pushing the barriers, stretching the forefronts of their fields or they aren't going to be funded," Thomas said.

At the end of the workshop, Shank expressed satisfaction with what the working group sessions produced. "The embryonic reports we have collected here are the fruits for the future."

The workshop was jointly sponsored by the Lab, BES, and the University of California's Office of the President. It was put together in response to the "Birgeneau Report," a DOE-sponsored review of the four national synchrotron radiation facilities. The report placed the ALS fourth in funding priority and cited the facility for shortcomings in its science programs, user relations, and institutional support.

Neville Smith, who heads the ALS scientific program, was recognized by both Dehmer and Shank for his central role in organizing this workshop. "It's been a stressful time here (following the Birgeneau report)," he said, "and the success of this workshop has been a morale booster. As I went around the different working group sessions, it was gratifying to see that so large a turnout of distinguished colleagues had come to Berkeley to help us develop a stronger scientific program."

Neville Smith
ALS scientific program head Neville Smith

Following this workshop, Smith said that the ALS management, in close consultation with the users' executive committee and the scientific advisory committee, will "devise a roadmap for the orderly build-out of the ALS." The next measure of success, he said, will be the extent to which the workshop's results "generate compelling research proposals" for the ALS.

The plenary sessions that opened and closed the workshop were chaired by Yves Petroff, director-general of the European Synchrotron Radiation Facility. In addition to his chair duties, Petroff also addressed the session, sharing his own experiences as head of a third generation light source that Shank praised as being a "model facility." Petroff joined the chorus in stating that large, expensive research facilities such as third generation synchrotron radiation sources must "push experimentation to its limit." He also stressed that such facilities must have strong in-house research programs as well as strong outside user programs with several "outstanding" experiments in the mix. Costs can be kept down with sound long-range planning, he said, and there should be a "good coupling" of the facility with "neighboring universities and laboratories."

Petroff expressed surprise at the Birgeneau report's conclusions because it is "too soon" to compare the ALS to older facilities such as the synchrotron radiation source at Brookhaven National Laboratory. "The Brookhaven facility is fabulous now, but it, too, had its problems when it was first started," he said.

This view was strongly seconded by Giorgio Margaritondo of Switzerland, who spoke on behalf of the European Commission Round Table for Synchrotron Radiation.

"The United States absolutely needs the ALS," Margaritondo said. "The scientific case for third generation light sources is clear and extremely strong for both soft and hard x-rays, and for coherence and brightness in soft x-rays, the ALS is the best."

Holding this type of a workshop to help plot the future scientific course of the ALS received high marks from Akito Kakizaki, representing the Photon Factory at the University of Tokyo. "The results of this workshop will have benefits for our upgrade of the Photon Factory," he said, an upgrade that is currently being debated in Japan.

Following the reports out of the working group sessions, the workshop concluded with an open forum in which ALS users had the opportunity to air their opinions directly with Werner Myer-Ilse, of the Center for X-Ray Optics, who chairs the ALS users' executive committee, and deputy lab director Pier Oddone, who is overseeing the Lab's response to criticisms in the Birgeneau report.

"Many aspects of our relations with users were reported to be a problem," Oddone candidly told an audience that filled the Bldg. 50 Auditorium. "We are charged with creating a world-class user program at the ALS. We have heard much talk at this workshop about brightness being the measure of quality (for ALS' beams). Our goal is to make our users shine."

In the enthusiastic exchanges that followed, the concerns raised included the possibilities of the ALS helping to defray user expenses, particularly with regards to travel and lodging, and an increase in technical support, including help with sample preparations. There were also calls to improve the proposal submission process and the allocation of beamline time and resources.

Oddone was joined by Shank in pledging that these issues would be taken under advisement. Said Shank, "The ALS is a national user facility, and it is therefore incumbent upon us to accommodate outsider users and balance between internal and external scientific programs."

Dehmer may have best summed up the spirit of the workshop in her concluding remarks. Noting that scientific surprises and technological revolutions can't be predicted, she pointed out that the only forecast about synchrotron radiation that has come true has been the increased use of such light. DOE, she said, shared a commitment with Berkeley Lab, to make the ALS "the premier source of soft x-ray and extreme ultraviolet light in the world."

Working Groups Determine Best Uses of ALS

The most important elements of the "Workshop on Scientific Directions at the Advanced Light Source," which was held last week at Berkeley Lab, were its eight working groups. Organized according to areas of research where the potential use of soft x-ray and extreme ultraviolet radiation is strongest, each group met separately at locations around the hill. Their mission was to identify the hottest issues in their fields and how the ALS could best be used to make a valuable contribution.

While the conclusions of these individual working groups are still being finalized, there are some overall highlights that can be reported. In the materials sciences, the topics generating the most excitement were unconventional superconductivity; magnetism for multi-electron extended systems; reduced dimensionality, including nanostructures, quantum wells, and mesoscopic devices; composite fermions; and the link between electronic structure and physical properties.

Many of the experiments being considered to study these topics could only be done at the ALS. Reasons cited included existing unique capabilities for soft x-ray absorption, emission, and scattering, and for magnetic circular and linear dichroism; plus potential capabilities in high-resolution angle-resolved photoemission; optical conductivity; and spin-polarized photoemission.

In the environmental and earth sciences, excitement centered around the "three S's" -- speciation of contaminants; spatial inhomogeneity at all length scales; sopping wet. With its unique capabilities for applying soft x-ray spectroscopy through the water window to in-situ speciation studies of soils, clays, minerals, and bio-organisms, the ALS received a strong endorsement here. There was even a call for the ALS to build-out an entire sector for environmental and earth sciences research.

In the biosciences, the fields of protein crystallography, x-ray microscopy and absorption spectroscopy received the most attention. For protein crystallography, the ALS was praised for its Macromolecular Crystallography Facility. There were calls for a superbend microcrystallography MAD (multiple-wavelength anomalous diffraction) beamline, greater use of existing ALS bend magnets, and the use of the ALS to do "all the proteins in a small bacterium" as part of an expanded effort in structural genomics. For x-ray microscopy and absorption spectroscopy, the ALS was seen as having an important potential role in medical studies that include breast cancer, disorders in human blood, and even Mad Cow disease. There was also a discussion of the ALS' enormous potential for diagnostic and functional imaging.

Enthusiasm was also high in areas involving catalytic materials, interfaces, chemical dynamics, and atomic physics. A more detailed report on the workshop results will be forthcoming in a future issue of Currents. The next Research Review will also feature a story on the science that is being done now at the ALS by users from outside of Berkeley Lab.

Search | Home | Questions