Particles from Comet 81P/Wild 2 viewed by ALS microscopes
Contact: S.A. Sanford,
NASA's $200-million, seven-year-long Stardust mission returned to Earth thousands of tiny particles snagged from the coma of comet 81P/Wild 2. Four ALS beamlines and the researchers using them were among the hundreds of scientists and dozens of experimental techniques in facilities around the world that contributed to the preliminary examination of the first samples. Adding to recent advances in cometary science showing the important role played by mixing of materials in the accretion disk where the planets of the Solar System had their birth, the first round of Stardust results suggests that the mixing started earlier in the planetary formation process and is more extensive than previously thought. Read more...
Publications about this research: D. Brownlee et al., "Comet 81P/Wild 2 under a microscope," Science 314, 1711 (2006). S.A. Sandford et al., "Organics captured from Comet 81P/Wild 2 by the Stardust spacecraft," Science 314, 1720 (2006); L.P. Keller et al., "Infrared spectroscopy of Comet 81P/Wild 2 samples returned by Stardust," Science 314, 1728 (2006); G.J. Flynn et al., "Elemental compositions of Comet 81P/Wild 2 samples collected by Stardust," Science 314, 1731 (2006).
Nature and origin of the cuprate pseudogap
Contact: Tonica Valla,
The workings of high-temperature superconductive (HTSC) materials are a mystery wrapped in an enigma. However, a team of researchers from the ALS, Brookhaven National Laboratory, and Cornell University has taken a major step in understanding part of this mystery—the nature and origin of the pseudogap. Using angle-resolved photoemission spectroscopy (ARPES) and scanning tunneling microscopy (STM), they have determined the electronic structure of La2–xBaxCuO4 (LBCO), a unique system in which superconductivity is strongly suppressed and static spin and charge orders develop near a doping level of x = 1/8. Read more...
Publication about this research: T. Valla, A.V. Fedorov, J. Lee, J.C. Davis, and G.D. Gu, "The ground state of the pseudogap in cuprate superconductors," Science 314, 1914, (2006).
Gary Krebs, the popular leader of the ALS User Services Group, passed away suddenly on the evening of May 22 in the midst of travel to Long Island for his annual visit to attend the National Synchrotron Light Source (NSLS) user meeting at Brookhaven National Laboratory. When he missed his nightly telephone call home, his worried wife asked his hotel to check on him. The security manager entered his room and found Gary sitting peacefully in a chair with no sign of distress. In addition to his wife Kathy, he leaves behind one son, Matthew, and in Vancouver, British Columbia, a brother, Dennis, and his parents.
Since arriving at the ALS in 1993, Gary had major impacts in several important areas: bringing the nascent accelerator survey and alignment system into adulthood as a functioning, productive tool, leading the first Users Services Group as it evolved to serve an ever-larger user community, playing a significant role as the ALS representative (and recently becoming chair) to the Berkeley Lab Best Practices Diversity Council, and as the ALS representative to the Lab group that has been formulating plans for an on-site 60-room Berkeley Lab Guest House. For the last two years, he also served as Deputy Scientific Director to the late Neville Smith and then as Deputy Science Advisor to Janos Kirz.
ALS Director Roger Falcone remembers, "Gary had sincere dedication to the people of the ALS. His enthusiasm was palpable for important projects that could benefit both users and staff, such as the Guest House, the Lab diversity council, and support for visiting students, and we shared in his pleasure in his successes in this work. I will miss his ability to generously welcome users to the ALS, his skills in shepherding our review processes, and his wisdom in helping to lead the ALS for many years." Former Director Janos Kirz echoes these sentiments, "Over the past three years I had the privilege to work closely with Gary, and I learned a lot from him. He was devoted to the ALS, and in particular to the users of the ALS. He worked hard to make the Guest House a reality, and his efforts are now bearing fruit. His passing is a great loss to all of us, and to me personally." Read the full article here.
Director's update at all-hands meeting
At an all-hands meeting on Thursday, May 17, ALS Director Roger Falcone gave a comprehensive overview of the past nine months, the status of the ALS today, and its future direction. The meeting began with a safety update by Jim Floyd, ES&H Manager. Most of the Radiation Safety Committee corrective action items have been completed, and the rest will be finished by October; two new floor operators have been hired; and there are ongoing health and safety initiatives in many areas, including waste management, laser safety, and hazardous gases.
Roger announced a major organizational change—the addition of Peter Denes as ALS Deputy for Engineering, allowing for tighter coupling between ALS and the Engineering Division. He then reported on several significant upgrades—ultrafast Beamline 6.0.1, which achieved first light in April; Beamline 7.3.3 (SAXS/WAXS), whose initial data are very clean; and the Sector 5.0 mirror upgrade, bringing a five to tenfold flux increase to the side stations. The top-off upgrade team completed a successful technical review of the open shutter injection safety issue in April 2007. MERLIN is scheduled for installation this summer, and will provide the highest resolution capabilities for photoemission and inelastic scattering experiments. Two new projects will soon be underway: the Guest House, which begins construction this October, and the User Support Building, which begins construction in March 2008.
Roger pointed out that some of the most important science in new materials involves key research done at ALS beamlines. Recently, pure samples of carbon were made permanently magnetic at room temperature. Researchers used Beamline 11.0.2 to obtain images of the magnetized portions. At ALS Beamline 7.0.1, a team led by Eli Rotenberg characterized the electronic structure of and controlled the band gap in a bilayer of graphene. ALS Beamline 9.3.2 was involved in the discovery of a platinum-nickel alloy that is 90 times more active than existing state-of-the-art platinum catalysts. In conclusion, Roger emphasized that safety and frontier science remain the ALS's top priorities, and that the renewals and upgrades will ensure that the ALS continues to grow and the users continue to have a premier facility.
First light for ultrafast Beamline 6.0.1
Contact: Phil Heimann,
Beamline 6.0.1, the hard x-ray femtosecond beamline, passed its readiness review in early April. It had first light on April 23 during an accelerator physics shift. The beamline is based on a double-crystal monochromator and extends the photon energy range of Beamline 6.0 from 2 to 10 keV. Following first light, three weeks were devoted to beamline commissioning. The flux, energy resolution, spot size, and background for the electron-beam slicing technique were measured. During the May/June shutdown a chopper is being sent back to the manufacturer, Rigaku, to improve its vacuum performance. Also, chopper synchronization electronics are being tested. After the shutdown, one further week of commissioning is scheduled as well as a first experiment to observe the mixing of infrared and x-ray photons in a diamond crystal. Ernie Glover (ALS) will lead the experiment.
Beamline 6.0.1 team. Left to right, front row: Bruce Rude, Phil Heimann, and Roger Falcone. Back row: Robert Schoenlein, Marcus Hertlein, and Ernie Glover.
Beamline 6.0.1 (hard x rays) and 6.0.2 (soft x rays) are undulator beamlines, which are dedicated to time-resolved experiments on the femtosecond and picosecond time scales. They have 100 times the intensity/pulse, 10 times the repetition rate, and 10 times the energy resolution of bend magnet Beamline 5.3.1. Beamline 6.0.1 is designed for electron-beam slicing, which generates 200-fs x-ray pulses. On Beamline 6.0.2, picosecond dynamics have been observed in the x-ray absorption spectrum of a manganite crystal by a team including Matteo Rini and Bob Schoenlein (Materials Sciences Division, Berkeley Lab) and Andrea Cavalleri (Oxford).
Contacts: Tony Warwick,
; Howard Padmore,
Tuesday May 1st saw the first technical review for the MAESTRO and COSMIC projects, which together will lead to the rebuilding of ALS Sector 7.0. Reviewers came from Berkeley Lab, ALBA in Spain, NSLS, and the Swiss Light Source, and were very enthusiastic, stating "We are unanimous in our belief that these conceptual designs will be turned into high performance, robust . . . beamlines."
COSMIC, which stands for Coherent Scattering and Diffraction Microscopy, will require two new beamlines for coherent imaging and scattering. These lines will deliver maximum coherent flux at modest spectral resolution and will employ horizontal dispersion. The spherical grating monochromators will select only the coherent fraction of the beam and operate independently for two separate endstations. Coherent imaging is being developed to employ x-ray illumination for lensless imaging using iterative techniques for phase retrieval and inversion of diffraction patterns to generate high-resolution images of objects microns in size. Coherent scattering is a related development with temporal and spatial correlations of speckle patterns used to watch phenomena such as phase transitions in magnetic materials, through scattering from domains. The experimental group includes Chris Jacobsen from Stony Brook University and Steve Kevan from the University of Oregon.
MAESTRO, which stands for Microscopy and Electronic Structure Observatory, will require a new high-resolution low-energy beamline for angle-resolved photoemission spectroscopy (ARPES). The experimental group, led by Eli Rotenberg, will upgrade the current Electronic Structure Factory at Beamline 7.0 and add a new capability for ARPES with a zone plate focusing to smaller than 50 nm. The MAESTRO beamline will have a high-resolution collimated SX700 monochromator. This design offers high resolution without entrance slits, with an adjustable degree of tolerance for source size, thermal deformations, and polishing errors of the optics. Its use will be particularly appropriate following the implementation of top-off operation, when the vertical size of the source will be reduced. See the ALS Strategic Plan for more information.
Users' Meeting, October 4–6
The Users' Meeting will be held on site at Berkeley Lab—from Thursday, October 4, to Saturday, October 6—and will offer a variety of invited talks, workshops, and selected science highlights. Meeting organizers are delighted to announce that this year's plenary sessions will be held in conjunction with the Molecular Foundry's annual meeting. In addition, three of the twelve workshops planned for the meeting will be joint ALS/Molecular Foundry events designed to provide opportunities for future collaborations. Ongoing facility projects such as top-off mode and the construction of the new ALS user support and the ALS user housing buildings will be discussed. The topical workshops are great opportunities to network, discuss recent successes, and combine efforts to address shared experimental challenges. Please contact the meeting chairs Peter Fischer (
) and Ken Goldberg (
) for additional information.
General user proposals submission deadline
The User Services Office is accepting general-user proposals from scientists who wish to conduct research in the general sciences at the ALS during the running period from January through June 2008. The deadline is July 15, 2007. (This deadline does not apply to protein crystallography proposals, which have a separate process and schedule.) To submit a new proposal, go to "ALS General User Proposal and Request for Beamtime." If you have an existing proposal for which you would like to receive beamtime during the January through June 2008 cycle, you must submit a Proposal Renewal Form. Scientists with active proposals have received instructions on how to submit proposal renewals. After review, the numeric rating of each proposal will be communicated to the PI, along with any comments from the external reviewers and the Proposal Study Panel. The cutoff rating for each beamline in the previous proposal cycle is published on the Web (see link below). The following resources are available for further information:
ALS Fellowship Program: Doctoral deadline and new postdoctoral fellowship
Contact: Adriana Reza,
The ALS offers two types of research fellowships: the Doctoral Fellowship in Residence and the newly instituted Postdoctoral Fellowship.
ALS Doctoral Fellowship in Residence. These fellowships enable students who have passed their Ph.D. qualifying or comprehensive verbal and written exams to acquire hands-on scientific training and develop professional maturity for independent research. Applicants must be full-time, currently enrolled students in a Ph.D. program in the physical or biological sciences pursuing thesis research based on the use of synchrotron radiation. The fellowships are offered as one-year appointments with the possibility of renewal. Successful applicants will be compensated with an $18,000 annual stipend. Additionally, fellows will be matched with an on-site mentor and have access to ALS resources, including beam time. Fellows are expected to present their results at a meeting or as a seminar at the end of the fellowship year. Applications for the 2007–2008 academic year are due by June 30, 2007. For more information, go to the ALS Doctoral Fellowships Web page.
ALS Postdoctoral Fellowship. The purpose of this new ALS fellowship program is to identify outstanding individuals in new and emerging scientific and engineering research fields and provide advanced training in synchrotron radiation science. Fellows become integral members of ALS research teams. Applicants must have received a doctoral research degree from an accredited academic institution in an appropriate scientific or engineering discipline within three years of the appointment start date. Applications are reviewed on a quarterly basis. Awards are initially for one year with the possibility of renewal for a second or third year, contingent on satisfactory annual performance reviews and funding availability. Salary is competitive with current ALS/Berkeley Lab postdoctoral fellows, ranging from $60,000 to $66,000 per year, depending on the number of years since receipt of the doctoral degree. Postdoctoral fellows are also eligible for midlevel career benefits. For more information on the fellowship and application requirements, go to the ALS Postdoctoral Fellowships Web page.