Safety incidents
prompt
all-hands meeting
 Responding
to a recent increase in safety incidents, the ALS held a mandatory
safety meeting for all ALS staff including those who are matrixed.
Acting Director Janos Kirz stressed that the common thread
through most of the accidents appears to be carelessness and
asked for suggestions to elevate safety awareness, especially
with the pending installation shutdown. Many insightful suggestions
were made and will be reviewed. As an immediate response,
the subproject leaders and section leaders have begun holding
briefings at the end of the work day. This will allow them
to discuss the safety implications of the plans for the following
day and transmit any safety concerns/lessons learned generated
by that day's work. First thing the next morning, the section
leaders will meet with their staff and go over the safety
issues and plans, as well as any safety concerns from the
previous day. We believe these meetings will help keep safety
in the forefront of everyone's mind, especially during the
busy shutdown.
Contact: Georgeanna Perdue, GMPerdue@lbl.gov
Electron trapping
by
molecular vibration
by Lori Tamura
In photoelectron spectroscopy experiments
performed at the ALS, a group of researchers has found that
electronic transitions normally thought to be forbidden can
in fact be excited in conjunction with certain types of molecular
vibrations. Specifically, they found that when the symmetry
of a linear triatomic molecule is broken by asymmetric vibrational
modes, photoelectrons can become temporarily trapped by the
molecule before ultimately escaping, giving rise to a broad
feature in the photoelectron spectrum known as a shape resonance.
This process represents a novel type of symmetry-breaking
phenomenon that has not been observed previously but appears
to be widespread. Such coupling between electronic motion
and nuclear motion becomes increasingly important as scientists
learn more about the geometry and dynamics of novel chemical
structures such as those found in nanodevices and transient
chemical species, and the results have implications for studies
that use photoelectron spectroscopy as a diagnostic tool.
Full
story.
Publication about this research: G.J.
Rathbone, E.D. Poliakoff, J.D. Bozek, and R.R. Lucchese, "Observation
of the symmetry-forbidden 5σu → kσu
CS2 transition: A vibrationally driven photoionization
resonance," Phys. Rev. Lett. 92,
143002 (2004).
Contact: Erwin Poliakoff, epoliak@lsu.edu
Influence of
topological spin
fluctuations on charge transport
by Art Robinson
Layered transition metal oxides are the
focus of intense research efforts because they might clarify
the superconducting mechanism of cuprate high-temperature
superconductors (HTSCs). A case in point is NaxCoO2
with x = 0.7, which is a parent compound for a family of cobaltites
that exhibits superconductivity. This class of materials is
also thought to be ideal for detecting the long-sought resonating
valence bond (RVB) state of matter proposed by Philip Anderson
of Princeton University in 1973. Researchers from Princeton
and the ALS are the first to use angle-resolved photoemission
spectroscopy (ARPES) to demonstrate the strongly electron
correlated nature of this material and to provide evidence
that charge transport is strongly influenced by topological
spin frustration. Full
story.
Publication about this research: M.Z.
Hasan, Y.-D. Chuang, D. Qian, Y.W. Li, Y. Kong, A. Kuprin,
A.V. Fedorov, R. Kimmerling, E. Rotenberg, K. Rossnagel, Z.
Hussain, H. Koh, N.S. Rogado, M.L. Foo, and R.J. Cava, "Fermi
surface and quasiparticle dynamics of Na0.7CoO2
investigated by angle-resolved photoemission spectroscopy,"
Phys. Rev. Lett. 92, 246402 (2004).
Contact: M.Zahid Hasan, mzhasan@princeton.edu
A new guide to
exploring
the protein universe
by Lynn Yarris
Proteins are the building blocks of living
cells and control the chemical processes that keep those cells
alive and functioning. Based on the total number of known
life forms on Earth, it is estimated that there are some 50
billion different types of proteins in existence today, and
it is possible that the protein universe could hold many trillions
more. How, then, does a scientist know where to find the most
densely populated (hence most promising) regions of protein
space to explore? Help is on the way in the form of a comprehensive
new 3-D map that brings order to the protein universe through
a manageable organization.
"We have constructed a protein-structure
space map (SSM) based on the distribution in 3-D space of
the 1,898 known unique protein structures," says Sung-Hou
Kim, a chemist who holds a joint appointment with Berkeley
Lab's Physical Biosciences Division and University of California,
Berkeley's Chemistry Department. "Because proteins with
similar structures and functions are clustered together in
the SSM, when the structure of a new protein is first identified
it can be placed in the appropriate location on the map to
reveal its neighbors and its evolutionary history. This information
can then be used to predict the protein's function, especially
when the prediction is not possible based on the protein sequence
alone."
While the construction of the SSM was
a computational tour-de-force, the data on which the analysis
was based came from the Protein Data Bank, an international
repository of protein structure data with substantial contributions
from light sources. Says Kim, "the availability of the
structures that we borrowed from the Protein Data Bank is
largely dependent on synchrotron light sources like the ALS."
Full
story.
Contact: Sung-Hou Kim, SHKim@lbl.gov
UEC Corner: Notes
from the Users'
Executive Committee
by Greg Denbeaux
 Thanks
to everyone who took a couple of minutes and responded to
my recent email to take action and help the ALS. If you have
not done so already, please look at the UEC
website and click on the "Take Action" button.
The next UEC meeting will be held on
Friday, May 6th. All interested users are welcome to participate,
so please let me know if you want more information about the
meeting. Our topics of discussion will include the user housing
issue and planning for the upcoming ALS Users' Meeting on
October 20–21.
(Contact: Greg Denbeaux, GDenbeaux@uamail.albany.edu)
2005 shutdown
features
IVID installation
The annual ALS shutdown for maintenance
and installation work is well underway, having begun on April
11 as scheduled. We have already installed an in-vacuum insertion
device (IVID), the first of its kind at the ALS, in Sector
6. The IVID is an undulator whose magnets are inside the vacuum
chamber, enabling smaller gap distances and thus, higher magnetic
fields. It will be used by the femtosecond beamline (6.0.1),
currently under construction. In addition, a newly machined
vacuum chamber with elliptically polarizing undulator (EPU)
trim coils has been installed in Sector 4, in anticipation
of a new EPU for the ultrahigh-energy-resolution MERLIN beamline
(4.0.1), currently in the design stage.
Installation of the in-vacuum insertion
device.
A full survey of the storage ring has been performed. It
was decided to forgo a girder-based alignment this year, in
favor of focusing on correcting long-term misalignment issues
with individual sextupole and bend magnets. Also, higher-order-mode
(HOM) dampers are being installed in the main rf cavities.
We anticipate handing the accelerator over on time to the
Accelerator Physics Group over the weekend of May 7 for them
to begin their start-up and tune efforts. Nine shifts of beamline
commissioning time are scheduled to follow, with user shifts
resuming on May 18.
Contact: Steve Rossi, SLRossi@lbl.gov
Synchrotron techniques
on BES site
 The
U.S. Department of Energy's Office of Basic Energy Sciences
(BES) has posted on its Web site a summary of the various
beamline
techniques that are practiced at synchrotron radiation
facilities along with some representative examples of research
accomplishments using these techniques. The site was assembled
in conjunction with a report being prepared by an Interagency
Working Group (IWG) for the Office of Science and Technology
Policy (OSTP) on synchrotron light sources in the United States.
The ALS was commissioned to condense the large amount of material
that had been submitted and to edit it into a form that would
be understandable to a lay person with a moderate science
background. The final result consists of 44 examples organized
under 12 techniques that fall into three basic categories:
spectroscopy, scattering, and imaging. I am grateful to all
who have contributed, and especially to members of the ALS
Technical Information Section who produced the site on the
desired short time scale.
Contact: Neville Smith, NVSmith@lbl.gov
Latest proposal
scores
posted online
The general sciences beam time allocation
process for the running period from July through December
2005 is complete. The number of proposals for the cycle was
310, up from 248 in the previous period. The number of eight-hour
shift requests for the upcoming cycle was 5932. A total of
2769 shifts, equal to about 46% of the total time requested
in the proposals, was allocated. Competition for beam time
on insertion-device beamlines was especially keen—general
users requesting beam time on the insertion-device beamlines
will continue to find the proposal process competitive; excluding
protein crystallography, approximately 31% of the requested
beam time was allocated. For more detailed results, including
beam-time score distributions and cut-off scores, go to the
proposal
scores Web page. The schedule
for the upcoming running period has also been posted.
Contact: Gary Krebs, GFKrebs@lbl.gov
In Memoriam:
Joan Minton
 A
longtime member of the ALS family, Joan Portello Minton, passed
away peacefully at home on March 26, 2005, after a long illness.
Joan began her Berkeley Lab career in 1993, when she was hired
as an administrative assistant at the ALS. During her tenure
here she provided valuable support to both the Experimental
Systems and the Scientific Support groups and to ALS Deputies
Ben Feinberg and Neville Smith. She was quickly recognized
for her exceptional writing ability and received an Outstanding
Performance Award for her work on the ALS Users' Guide, a
publication that received an international Distinguished Technical
Communication Award. In 1999, Joan accepted a new assignment
within Berkeley Lab's Physical Biosciences Division, coordinating
and developing research and grant proposals. Joan was dedicated
to her job, to those she supported at the ALS, and to the
ALS as a whole. She was a role model of reliability, work
ethic, communication, and willingness to grow and accept new
responsibilities. All who knew her were touched by her generosity,
creativity, and ability to enjoy life as it comes. A scholarship
fund has been set up in Joan's name; contributions may be
sent to A.U.H.S.D. / Joan Minton Scholarship Fund, 1212 Pleasant
Hill Rd., Lafeyette, CA 94549.
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