Nanodiamonds
show
buckyball surface
by Lori Tamura
If you blast a diamond into (nanosized)
smithereens you will get... buckyball fragments? In fact,
scientists from Lawrence Livermore National Laboratory have
found that diamonds made up of up to a few hundred carbon
atoms do not exhibit the smooth, faceted surfaces commonly
associated with crystals. Instead, at this scale, portions
of the diamond's surface will spontaneously buckle into the
curved, geodesic-dome structure found in buckyballs. The researchers
came to this surprising conclusion after performing ab initio
calculations as well as x-ray absorption and emission experiments
on nanodiamonds synthesized in detonation waves from high
explosives. The discovery of this new family of carbon clusters,
dubbed "bucky diamonds," may have implications for
a wide range of areas, from astronomy, where diamonds are
studied as a constituent of meteorites and interplanetary
dust, to optoelectronics, where nanodiamonds might be used
as photonic switches and tunable lasers. Full
story.
Publication about this research: J.-Y. Raty,
G. Galli, C. Bostedt, T.W. van Buuren,
and L.J. Terminello, "Quantum Confinement and Fullerenelike
Surface Reconstructions in Nanodiamonds," Phys. Rev.
Lett. 90, 037401 (2003).
Contact:
Lou Terminello, terminello@llnl.gov
Demonstration
of coherent
x-ray diffraction imaging
by Art Robinson
In order to image the interiors of intrinsically
noncrystalline objects with nanometer resolution, several
groups have been developing the technique of coherent x-ray
diffraction (or lensless) imaging; however, up until now they
have required the use of additional image information to supplement
the diffraction pattern. At the ALS, a collaboration comprising
researchers from Lawrence Livermore National Laboratory, Arizona
State University, and the ALS has demonstrated the ability
to make two-dimensional images of clusters of gold balls 50
nm in diameter from diffraction data alone with a resolution
of 20 nm.
Full story.
Publication about this research: S. Marchesini,
H. He, H.N. Chapman, S.P. Hau-Riege, A. Noy,
M. R. Howells, U. Weierstall, and J.C.H. Spence,
"X-ray image reconstruction from a diffraction pattern
alone," Phys. Rev. B 68, 140101(R)
(2003).
Contact: Stefano Marchesini, marchesini@llnl.gov
Designing a novel
globular protein fold
by Art Robinson
A major challenge of computational structural
biology has been to create, from scratch, new proteins with
heretofore unobserved three-dimensional structures. A collaboration
from the University of Washington, Seattle, the University
of North Carolina, Chapel Hill, and the Fred Hutchinson Cancer
Research Center has now developed and demonstrated a methodology
for protein-structure prediction and design by creating the
first artificial globular protein with a novel topology, a
93-residue protein called Top7. Significantly, the x-ray structure
of Top7 agreed almost precisely with the structure specified
by the computational model. Full
story.
Publication about this research: B. Kuhlman,
G. Dantas, G.C. Ireton, G. Varani, B.L. Stoddard,
and D. Baker, "Design of a novel globular protein
fold with atomic-level accuracy, " Science 302,
1364 (2003).
Contact: David Baker, dabaker@u.washington.edu
New x-ray microscope
receives funding
 Researchers
with Berkeley Lab and the University of California at San
Francisco have received $2.5 million in grants to build a
new x-ray microscope at the ALS. Users Carolyn Larabell and
Mark Le Gros (both of Berkeley Lab) are the principal investigators.
The first-of-its-kind microscope holds forth the promise of
"cat scans" for biological cells and other unprecedented
capabilities for cell and molecular biology studies. It also
promises a better understanding of human diseases at the molecular
level and possibly new discoveries for treating those diseases.
Carolyn and Mark have been using XM-1, an existing x-ray microscope
at Beamline 6.1.2, to demonstrate the potential of using this
technology in cell and molecular biology studies. XM-1 was
designed and is operated by the Center for X-Ray Optics primarily
for the study of materials. The new microscope, dubbed XM-2,
will be optimized for biology and will therefore have several
advantages, including improved zone plates, the optic devices
composed of nanometer-scale concentric metal rings that are
used to focus x-rays for imaging purposes. Full
story.
Contact: Carolyn Larabell, CALarabell@lbl.gov
UEC Corner: Notes
from the Users'
Executive Committee
by Dennis Lindle
The UEC met for the first time this year on March 2.
For the uninitiated, a typical UEC meeting is an all-day affair
during which we hear updates from the ALS administration and
staff on user and facility issues running the gamut from big-picture
topics (e.g. strategic planning, upgrading the ALS) to more
focused, quality-of-life concerns (e.g. housing, parking).
Aside from its primary role in advising the ALS leadership
on behalf of the user community, the UEC is also responsible
for planning the annual Users' Meeting, which will be held
October 18–20 this year.
At our March 2 meeting, we discussed
three topics of broader interest to the user community. (1)
ALS Upgrades. The highest priority is to modify the ALS to
operate in "top-off" mode, in which the ring current
would be maintained at a near-constant 500 mA by small injections
at brief intervals (seconds to minutes). The Accelerator Physics
Group is currently working with beamline scientists and users
to assess the impact of injecting electrons with beam available
(an essential aspect of "top-off" mode) on various
experiments around the ring. Operation in "top-off"
mode is expected to begin in about three years. (2) Strategic
Planning. Another high priority for the ALS is upgrading existing
insertion devices and beamlines to take advantage of new scientific
opportunities and technological advances. To optimally achieve
this in a systematic fashion, the ALS has begun a strategic-planning
exercise that will culminate in a DOE-sponsored review of
the ALS about a year from now. ALS staff are in the midst
of a series of retreats looking ahead 5–10 years in
order to identify key opportunities. As part of this process,
in about two months, there will be a joint ALS/UEC retreat
to obtain users' perspectives. If you have recommendations
for future scientific or technological developments at the
ALS, please feel free to contact me or another member of the
UEC. (3) User Support Building. This new building, which will
replace Building 10 adjacent to the ALS, will address numerous
space needs of the user community, including high-bay staging
and more office space. Unfortunately, the expected start date
for this project (FY 2005) has been delayed two years due
to funding difficulties. The UEC is clearly disappointed with
the delay, but we are committed to working with ALS and Berkeley
Lab management, who are very supportive of the project, to
minimize its time to completion. Please stay tuned for more
news as these issues continue to unfold.
(Contact: Dennis Lindle, lindle@unlv.nevada.edu)
Apply now for2004–2005
doctoral fellowships
 The
ALS is offering several doctoral fellowships in residence
for the 2004–2005 academic year. Through these fellowships,
qualified graduate students will gain hands-on experience
in the use of synchrotron radiation by performing a major
part of their thesis work at the ALS. Applicants must be full-time
Ph.D. students pursuing synchrotron-radiation-based research
in the physical or biological sciences and have passed all
qualifying or comprehensive verbal and written examinations.
Individuals from underrepresented groups are encouraged to
apply. The deadline for applying is May 1, 2004.
The fellowships include a one-year appointment
(with the possibility of renewal) and a $16,000 annual stipend.
Fellows will be matched with an on-site mentor (generally
a beamline scientist) and have access to ALS resources, including
beam time. Fellows are expected to present their results at
a meeting or a seminar at the end of the fellowship year.
Read more.
Contact: Zahid Hussain, ZHussain@lbl.gov
Mezzanine construction
completed,
shutdown plans set
Construction of the office build-out
in the ALS mezzanine has been completed. Scientific Support
Group members began moving into their new home in late March.
The mezzanine is now completely built out with the exception
of one space, which has already been designated as the future
home the Chemical Dynamics Group's laser lab.
Planning for this year's shutdown is
well underway and it is shaping up to be a very busy time.
The ALS will shut down on April 26 for maintenance and
installation. Following a brief beamline commissioning period,
the ALS will reopen for user operations on June 10. Major
work to be accomplished during the shutdown includes a complete
survey and alignment of the storage ring, the replacement
of the W16 wiggler in Sector 5 with a W11 insertion device
(for a planned femtosecond beamline), replacement of the superbend
cold heads, and installation of higher-order-mode dampers
on third-harmonic cavities 1, 2, and 3.
We plan to take advantage of the long
shutdown period to accomplish two facility projects as well.
To accommodate the increased usage of liquid nitrogen at the
ALS, a new and larger bulk storage tank will be installed.
The old 2300-gallon tank will be replaced with a 6000-gallon
tank. The increased size of the tank also necessitates a new
foundation. A building column in Sector 4 will also be removed
to make way for the new meV-resoution beamline (MERLIN).
Contact: Steve Rossi, SLRossi@lbl.gov
Publications
needed by April 9 for
inclusion in Activity Report
If you have recently published any ALS-related
work in a scientific journal, conference proceedings, or book
chapter; completed a Ph.D. thesis; or received a patent based
on work done at the ALS, please let us know by April 9
so that your work can be reported to the DOE as well as cited
in the 2003 ALS Activity Report.
Simply go to the User
Services Online Forms Web page. This works best if you
use Netscape 6 or 7 or Microsoft Internet Explorer 5.0 or
greater; otherwise, you will lose data if you hit the "Back"
key. Be sure to first use the "Search for Publications"
option, to see if your publications have been previously entered
into our database by a collaborator. If you are one of our
more prolific publishers or have a common last name, you can
limit the search by initials, beamline, year published, or
journal name. Then, please use the "Submit Publication
Listings" option and enter the information requested.
Most of the mandatory fields are required by DOE. The most
important fields are "Title" and "Journal or
Publication Name." If you don't know something, such
as the specific page, or month published, please type n/a
in the field. We'll attempt to track it down.
Your timely response will be greatly
appreciated, as it is imperative that we accurately report
the number of ALS-related publications to the DOE and that
we include them in our annual Activity Report. Remember, if
it's on your CV, and all or part of the work was done at the
ALS, it should be in our database!
Contact: alsuser@lbl.gov |
