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The 2008 ALS Users’ Meeting: A 15th Anniversary Celebration
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Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy Graphene—a single layer of carbon atoms arranged in a honeycomb lattice—has very high conductivity that can be tuned by applying a gate voltage. The charge carriers in graphene can travel ballistically over great distances (about 1 micron) without scattering. These unusual electronic properties make graphene a promising candidate for future nanoelectronics. Using infrared spectromicroscopy at Beamline 1.4, a group of researchers from the University of California at San Diego, Columbia University, and the ALS has succeeded in probing the dynamical properties of the charge carriers in graphene with an accuracy never before achieved. Their results have uncovered signatures of many-body interactions in graphene and have demonstrated the potential of graphene for novel applications in optoelectronics. Read more…
Publication about this research: Z.Q. Li, E.A. Henriksen, Z. Jiang, Z. Hao, M.C. Martin, P. Kim, H.L. Stormer, and D.N. Basov, “Dirac charge dynamics in graphene by infrared spectroscopy,” Nature Physics 4, 532 (2008). |
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Watching Electrons Do Chemistry in Liquids: Time-Resolved Soft X-Ray Spectroscopy of Solvated Molecules by Nils Huse and Robert Schoenlein
Using the recently commissioned Beamline 6.0.2 , we have applied time-resolved soft x-ray spectroscopy at the Fe L3 edge to reveal the electronic dynamics of an ultrafast Fe(II) spin transition in solution. We measured the absorption of the low- and high-spin states after the photoinduced metal-to-ligand charge transfer. These are to our knowledge the first time-resolved transmission spectra of solvated molecules ever recorded in the soft x-ray region. Read more… |
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Thank You for a Wonderful Users’ Meeting! I would like to thank all of you for your participation in the 2008 ALS Users’ Meeting. From the conversations I had during the meeting as well as from comments I received afterwards, it seems as if everyone had a wonderful time and enjoyed the program. In particular, many of you pointed out how well the Daniel Chemla memorial session was received and how much you appreciated the memories shared by the speakers during the session. Also very well received was the keynote address by Congresswoman Lynn Woolsey, the town hall meeting on Monday afternoon, and the awards session, which featured three outstanding talks by the award winners James Berger (Shirley), Eric Gullikson (Halbach), and Joanna Bettinger (Best Student Poster). Finally, the poster session, held on Monday evening during the reception sponsored by our vendors, featured more than 70 contributions from ALS users. It was a true pleasure to see the ALS patio buzzing with excitement. Let me also say a big THANK YOU to Phil Heimann, Wayne Stolte, and the ALS staff for an excellent meeting. If you have any comments or suggestions for future meetings, please send me an email (hohldag@stanford.edu) so that we can discuss your ideas at our next UEC meeting on November 3. Vote Now. At the end of 2008, the terms of three representatives on the Users’ Executive Committee will come to an end. I would like to use this opportunity to thank Elke Arenholz, Alessandra Lanzara, and Tony van Buuren for their valuable contributions to the user community over the past three years. Eight ALS users from universities and facilities across the U.S. have been selected as candidates to take their place and represent your interests from 2009–2011. Vote online now for the three candidates of your choice using the online voting form. You can find their biographies on the UEC voting web site. Deborah Smith Moves Over to the User Services Office
Before coming to the Lab, Deborah worked at an HVAC engineering firm that did tenant improvement in San Francisco. When she arrived in 2005, she discovered that she loved it. “This place is its own city, and the science done here has a tremendous impact.” She started out in Computing Sciences, then did a stint in EH&S before finding her home at the ALS. “The scientists here are really passionate about what they do, and they energize me to do what I do.” Deborah is located in the User Services Office in Building 6, Room 2212E, and her door is always open. You can also contact her by email at DASmith@lbl.gov or telephone at 510-495-2001. |
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CXRO Scientists Star at Nanochip Symposium SEMATECH, the Semiconductor Manufacturing Technology consortium, held an International Symposium on EUV Lithography last month at Lake Tahoe to explore the future of computer chip manufacturing. Chris Anderson and Patrick Naulleau of the Center for X-Ray Optics (CXRO), with colleague Thomas Wallow of Advanced Micro Devices, won the Best Paper award for their discussion of nanoscale patterning, using 13.5-nm wavelength extreme ultraviolet light (EUV) at ALS Beamline 12.0.1. Chris Anderson is a UC Berkeley graduate student in Applied Science and Technology. As cochair of the symposium, Naulleau also presented an overview of North American EUV research. Read more… Crosscutting Review of Environmental Science at the ALS
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__________________________________________________ Bulletin Board Another safe and successful ALS shutdown is in the books. The User Support Building Project was able to complete the work thought to most likely cause vibration problems for users, which included the excavation of the site, import and compaction of engineered fill, and the drilling and placement of 51 piers. The third of four phases of a seismic retrofit of the ALS dome was also completed. A significant number of technical projects were accomplished, including the installation of 14 apertures to enable safe top-off operation; a removal, repair, and reinstallation of the in-vacuum insertion device in the straight section of Sector 6, and a safety improvement to the superbend magnets. Many other tasks were also completed, and once again we owe great thanks to our technical staff for their diligent and safe work.
Readying the site for the User Support Building. ALS Spectrum Debuts October 13
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For the user runs from October 11–19: Beam reliability*: 93.1%; Completion**: 90.5%. Questions about beam reliability should be sent to David Richardson. Requests for special operations use of the “scrubbing” shift should be sent to Rick Bloemhard (ALS-CR@lbl.gov, x4738). Long-term and weekly operations schedules are available here. View the ring status in real time here.
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This year’s ALS Users’ Meeting, held on October 13–15, looked back on several notable achievements over the past year, including the successful triennial Department of Energy Office of Basic Energy Sciences (BES) Review, full-energy injection (from 1.5 to 1.9 GeV), increased photon flux (from 400 mA to 500 mA), the near completion of top-off (ETA early 2009), the installation of the MERLIN insertion device, and the installation and successful testing of the quasi-single-bunch operation system. Approximately 400 people attended the conference, which included plenary and poster sessions, a student poster competition, and ten workshops (including a joint ALS/SSRL workshop). At the banquet, held on Tuesday, October 14, awards were presented for scientific achievement, instrumentation, user services, and student posters. Thanks go to program co-chairs Wayne Stolte and Phil Heimann for organizing this 15th anniversary meeting. 
Ultrashort laser pulses can follow chemical reaction kinetics in real time, but extracting quantitative information on the evolving molecular and electronic structure from optical measurements remains a major challenge. In recent years time-resolved laser spectroscopy and established x-ray methods have been combined to create new tools, which are used to directly probe the local electronic and molecular structure in time and energy. Hard x rays are typically used to probe atomic arrangements through scattering and K-edge spectroscopy; soft x rays, sensitive to valence-charge distributions, hold tremendous potential for following the formation and dissolution of chemical bonds in real time. The information gleaned from ultrafast x-ray probes is essential to understand the cooperative relationship between electronic charge distributions, atomic rearrangement, and the formation of new molecular structures. It is particularly effective for understanding molecular dynamics in solution, where much important chemistry occurs and where the solvent environment substantially influences reaction dynamics through interaction with the valence charge distribution.
Deborah Smith, formerly of the ALS Experimental Systems Group, has joined the 
The Crosscutting Review of Environmental Science at the ALS took place over a two-day period on October 9–10, 2008. The distinguished committee for the review consisted of Ingrid Pickering (Chair, University of Saskatchewan), Paul Fenter (Argonne National Laboratory), John Parise (Stony Brook University), David Vaughan (University of Manchester), and John Zachara (Pacific Northwest National Laboratory). The plenary speakers at the review covered a diverse range of topics in environmental science that had been addressed using the unique characteristics of the ALS and included Gordon Brown, Jr. (Stanford University/SSRL), Alain Manceau (University of Grenoble), Brandy Toner (University of Minnesota Twin Cities), and Andrew Westphal (University of California at Berkeley). The plenary sessions were followed by specific scientific presentations of results from ALS beamlines that have ongoing environmental sciences activities and from those beamlines that anticipate substantial use for environmental science in the near future.
During the review, all of the speakers highlighted compelling science that could be performed at the ALS in the future and comprehensively addressed the needs for upgrades, improvements, and future beamlines to serve the needs of the environmental science community now and into the future. A working lunch for both current and prospective ALS environmental sciences users and the review committee was held on the first day without ALS management present, providing an open forum for direct environmental science community discussion and input.
A new publication from the ALS debuted the ALS Users’ Meeting and is now available