The 2015 User Meeting brought together 405 ALS users from around the world, many of whom shared insights and sparked discussion with presentations of their ALS research highlights. UEC Chair Chris Cappa launched the meeting with a welcome, followed by another from Berkeley Lab Director Paul Alivisatos. Speaking of the vitality and community that’s key to the ALS, Alivisatos also touched on how the ALS could be utilized and optimized with a high coherence upgrade. ALS Director Roger Falcone outlined short-term and long-term planning for the ALS, with ongoing efforts to develop new beamlines and capabilities within the next three years and longer-term.
DOE Associate Director of Science for Basic Energy Science (BES), Dr. Harriet Kung, delivered a Washington update, beginning with an acknowledgement that science funding remains challenging, with 2015 marking the third consecutive year that funding has been below request. “We are hoping to rally support to turn the tide around,” Kung said, and encouraged users to get in touch with their elected representatives and express the importance of user facilities and basic research. Kung summarized BES research on future light sources with the statement: “Diffraction-based light sources are the future, and the U.S. has to make an investment.”
The first scientific speaker of the morning, Stanford University’s Gordon Brown, spoke about x-ray spectroscopic, scattering, and imaging studies of earth materials and processes. Brown and his team have used STXM techniques at the ALS to determine various soil characteristics to inform their research on abiotic and biotic crustal nucleation and growth. Brown’s research has also focused on the important role of iron hydroxide nanoparticles in the environment, and their STXM images from the ALS have shown the properties of the iron distribution and organic carbon in mine drainage samples.
John Turner, from the National Renewable Energy Laboratory (NREL), was up next with a lively presentation about semiconductor systems and catalysis for photoelectrochemical (PEC) water splitting. In the search for sustainable paths to hydrogen for fuel, ammonia, and energy storage, economics are the final determination, says Turner, and the cost of hydrogen is mainly determined by the cost of electricity. Turner has focused his research on molecular catalysts for PEC water splitting, in an effort to build higher-efficiency water splitting devices.
Hewlett Packard Research Scientist Stan Williams spoke about the future of transistors and the search for higher resolution in energy, space, and time. He and his research team have turned to the human brain for clues, which has led them to the memristor. The fourth basic circuit element, the memristor (short for “memory resistor”) joins the other passive elements to create a device with the ability to “remember” changes even when it loses power. Williams expressed that the most important thing he and his team bring to HP and the industry at large is modeling. “High quality models enable our circuit designers to actually design accurate circuits,” he says. Williams uses STXM at the ALS to investigate nanodevices, and they need the best possible energy resolution to do this. “Our research at the ALS has led to fundamental materials understanding,” he says.
Longtime ALS user Chuck Fadley, a UC Davis physicist, was up next with a presentation about x-ray optics and the study of buried solid/liquid (and solid/solid) interfaces. Fadley began with the all-important question of what’s happening at the interface, which he says drives a lot of his group’s research. Fadley uses the ambient pressure photoemission capabilities of the ALS to examine molecular-level structures, tuning to special resonant conditions to improve depth selectivity.
UC Berkeley’s Ting Xu spoke about deciphering hierarchical assemblies in supramolecular nanocomposites. Her research is focused on metamaterials, with a top-down engineering approach. Engineering supramolecular nanocomposites gives rise to materials with tailored mechanical, electrical, and optical properties for energy harvesting, storage, microelectronics, memory storage, sub-10-nm lithography, and light management.
ALS staff updates included User Services Group Leader Sue Bailey, who gave an overview of the new publication reporting system and the updated ALS experiment safety process. David Robin, head of the ALS Accelerator and Fusion Research Division (AFRD), reviewed accelerator, instrumentation, and controls upgrades.
The afternoon concluded with the ever-popular ALS Student Poster Slam, which gives recognition to significant student research conducted at the ALS. Students presented their posters on a wide variety of topics, with first prize going to Gregory Su, from UC Santa Barbara, for his poster “Phase Separated Polymer Blends for Organic Memory.” Su gave a talk about his research the following morning, which focuses on using polymers and polymer blends for organic memory.
Tuesday morning began with a talk from Sherry Chen, from the Hong Kong University of Science and Technology, about studying reversible phase transformations by synchrotron x-ray Laue microdiffraction. Chen uses Beamline 12.3.2 to study unique microstructures, with the critical issue being functional degradation. The applications for research about these microstructures include medical devices and microelectronics devices.
This year’s Shirley Award winner, Beamline 8 staff scientist Wanli Yang, spoke about his research using soft x-ray spectrocscopy to study alkaline-based battery materials. The effort to improve batteries to meet growing energy needs requires a better understanding of their characteristics. “Battery research has a different focus depending on end use,” says Yang. “So we need different parameters of imaging.” Soft x-rays detect the key electron states that define the electronic properties of batteries, says Yang, and yet his research is still in the early stage of discovering how it can benefit the battery industry.
The Molecular Foundry’s David Prendergast, a computational physicist who often works with ALS users who are doing collaborative research at the two user facilities, spoke about understanding working interfaces at the nanoscale. “In-situ techniques are really useful to provide a unique insight on material system functionality,” says Prendergast. “But difficult theoretical problems remain.”
Alexander Laskin, from Pacific Northwest National Lab (PNNL), gave a talk about the discovery of unique atmospheric solid particles through chemical imaging. Using synchrotron techniques, researchers can assess particle types in the atmosphere and determine how they are formed and how they change. Laskin’s work also focuses on monitoring atmospheric aging and the atmospheric chemistry of aerosols.
Ilya Belopolski, a Princeton University physics graduate student in Zahid Hasan’s group, gave the final talk of the day, about the discovery of Weyl fermion and topological Fermi arc quasiparticles in condensed matter systems.
The second day of the 2015 User Meeting concluded with the annual awards dinner.
The Klaus Halbach Award for Innovative Instrumentation at the ALS was awarded to Hans Bechtel, Michael Martin, and Markus Raschke for the development of Synchrotron Infrared Nano Spectroscopy (SINS). The Tim Renner User Services Award was awarded to David Malone for his efforts to ensure users’ experiments run safely. The two were joined by Shirley Award winner Yang and Student Award winner Su.