# Five Years of Basic Energy Sciences Accomplishments

Presented below are some significant Basic Energy Sciences (BES) program
accomplishments from FY 2001, FY 2000, FY 1999, FY 1998, and FY 1997.
These vignettes appear in the BES portion of the President's FY 2003, FY
2002, FY 2001, FY 2000, and FY 1999 Budget Requests to Congress,
respectively. The selected program highlights are representative of the
broad range of studies supported in the BES program. These brief
accounts describe the discovery of new knowledge, the rapidity with
which such new knowledge can often be incorporated into other scientific
disciplines and into the commercial sector, and the great potential of
new knowledge for future impacts in energy production and use.

**Selected FY 2001 Scientific Highlights/Accomplishments**

**Materials Sciences and Engineering Subprogram\
**

***Micro-size Light Emitters for Solid State Lighting Applications.***
Energy savings of tens of billions of dollars per year could be achieved
by replacement of household 100-watt light bulbs by white light emitting
diodes (LED) made by mixing LEDs emitting primary colors. However,
improved LED efficiency is necessary before such replacement becomes
feasible. New research has shown that interconnecting hundreds of
micro-size LEDs to replace larger conventional LEDs can boost the
overall emission efficiency by as much as 60 percent.

***A New Method for Obtaining Crystal Structures Without Large
Crystals.*** High-resolution x-ray diffraction using polycrystalline
samples ("powders") rather than traditional single-crystal samples has
advanced to the point where the structures of complex materials
including oxides, zeolites, and small organic structures can be solved.
Advantages of powder diffraction are that it is not affected by crystal
fracture and polycrystalline samples can be formed over a much wider
range of conditions than large single crystals. Recently, powder
diffraction was demonstrated for large molecules, such as proteins, that
were considered far too complex for powder diffraction experiments. In
addition to the many important applications to materials sciences, this
technique will also be useful in chemistry and biosciences.

***NMR and MRI Outside the Magnet.*** NMR (nuclear magnetic resonance)
imaging and MRI (magnetic resonance imaging) have required large
high-field magnets that impose extremely uniform magnetic fields upon
the sample. In many circumstances, however, it is impractical or
undesirable to place or rotate objects and subjects within the bore of
such a large magnet. A new approach for the recovery of highly resolved
NMR spectra and MRI images of samples in grossly non-uniform magnetic
fields was recently demonstrated. The approach will be useful for the
enhanced study of fluids contained in porous materials, such as deep
underground oil-well logging studies, and is expected to have dramatic
research applications in chemistry, materials sciences, and biomedicine.

***Terabit Arrays (One trillion bits per square inch).*** A 300-fold
increase in magnetic storage density has been achieved using a patented
technique of self-assembly of block copolymers under the influence of a
small voltage. The new technique is simple, robust, and extremely
versatile. The key to this discovery lay in directing the orientation of
nanoscopic, cylindrical domains in thin films of block copolymers. By
coupling this with routine lithographic processes, large area arrays of
nanopores can be easily produced. Electrochemical deposition of metals,
such as cobalt and iron, produces nanowires that exhibit excellent
magnetic properties, key to ultrahigh density magnetic storage. The
nanowires are also being used as field emission devices for displays.

***Observations of Atomic Imperfections.*** A new electron beam
technique has been developed that has measured atomic displacements to a
record accuracy of one-hundredth of the diameter of an atom. Such small
imperfections in atomic packing often determine the properties and
behavior of materials, particularly in nano-structured devices. This
capability has been made possible by a new technique that couples
electron diffraction with imaging technology. The result is a greatly
enhanced capability to map imperfections and their resulting strain
fields in materials ranging from superconductors to multi-layer
semiconductor devices.

***Semiconductor Nanocrystals as "Artificial Leaves."*** Recent
experiments demonstrated that carbon dioxide could be removed from the
atmosphere with semiconductor nanocrystals. These "artificial leaves"
could potentially convert carbon dioxide into useful organic molecules
with major environmental benefits. However, to be practical, the
efficiency must be substantially improved. New theoretical studies have
unraveled the detailed mechanisms involved and identified the key
factors limiting efficiency. Based on this new understanding,
alternative means for improving efficiency were suggested that could
lead to effective implementation of artificial leaves to alleviate
global warming and the depletion of fossil fuels.

***\"Magic\" Values for Nanofilm Thickness.*** A key issue for
nanotechnology is the structural stability of thin films and the devices
made from nanostructures. It was recently demonstrated that nanofilms
are significantly more stable at a few specific values of film
thickness. The origin of this effect arises from the confinement of
electrons within the film leading to electronic states with discrete
energy values, much as atomic electrons are bound to the nucleus at
discreet energy levels. Calculations demonstrated that increased
stability occurred when the number of electrons present in the film
completely filled the set of available states, just as filled electronic
shells make the mobile gases very stable.

***Materials Resistant to Damage from Nuclear Waste.*** The ability to
predict the composition and structure of materials that are resistant to
radiation damage, such as in nuclear waste storage, has been formulated
on a firm scientific basis. Current nuclear storage materials cannot
resist radiation damage for the required thousands of years because
radioactive emissions in a storage material jostle atoms out of their
carefully ordered arrangements. These materials become unstable and
eventually leach into the environment. Computer simulations and
experiments revealed that a special class of complex ceramic oxides
called fluorites is able to resist this fate. The fundamental principle
is rather simple: the configurations of atomic arrangements in these
oxides are relatively disordered to begin with allowing them to tolerate
displaced atoms caused by radiation.

***Brilliant X-Rays Shine Light on Welds**.* Using high-brightness
synchrotron radiation, the details of microstructural changes of welds
were mapped and studied for the first time. This advanced capability
shows how the welding process alters the structure and changes the
properties of metals. Its application is virtually unlimited, since it
can investigate dynamic changes in crystal structure near the melting
point of any metal. Knowledge gained from this award winning work on
titanium and stainless steels is being used to advance and refine
theories and numerical models of welding fundamentals. Dramatic savings
to the U.S. economy would result from better quality, more reliable
welds.

***Micro Lens for Nano Research**.* A silicon lens that is 1/10 the
diameter of a human hair has been fabricated and used to image
microscopic structures with an efficiency 1,000 times better than
existing probes. The combination of high optical efficiency and improved
spatial resolution over a broad range of wavelengths has enabled
measurement of infrared light absorption in single biological cells.
This spectroscopic technique can provide important information on cell
chemical composition, structure, and biological activity.

***Nanofluids**.* Nanofluids (tiny, solid nanoparticles suspended in
fluid) have been created that conduct heat ten times faster than thought
possible, surpassing the fundamental limits of current heat conduction
models for solid/liquid suspensions. These nanofluids are a new,
innovative class of heat transfer fluids and represent a rapidly
emerging field where nanoscale science and thermal engineering meet.
This research could lead to a major breakthrough in making new composite
(solid and liquid) materials with improved thermal properties for
numerous engineering and medical applications to achieve greater energy
efficiency, smaller size and lighter weight, lower operating costs, and
a cleaner environment.

**Chemical Sciences, Geosciences, and Energy Biosciences Subprogram**

***Capturing Molecules in Motion with Synchrotron X-Ray Pulses.***
Photochemical conversion of solar energy depends on light-driven
chemical reactions. Absorption of light ultimately leads to atomic
rearrangements necessary to produce photochemical products. The
intermediate molecular configurations created by absorption of light are
short-lived and their structures are largely unknown. In novel
experiments at the Advanced Photon Source, molecular structures of
laser-generated reaction intermediates in solutions, having lifetimes as
short as 28 billionth of a second, have been obtained. Future
experiments are planned that will allow for capture of intermediate
structures on even shorter time scales. These studies are providing the
fundamental knowledge needed to develop artificial photoconversion
devices.

***Early Precursor Identified in Water Radiolysis**.* Radiolytic
decomposition of water produces hydrogen gas, which is flammable and
potentially explosive. This is of concern in maintenance of
water-moderated nuclear reactors, long-term storage of transuranic
fissile materials containing adsorbed water, and management of
high-level mixed-waste storage tanks. In recent studies on the effects
of ionizing radiation on condensed media, a common precursor to
essentially all hydrogen from irradiated water has been discovered. This
precursor is a solvated electron. External intervention and capture of
this precursor can prevent the generation of hydrogen gas from water.
The reactivity of the precursor with a large number of scavengers has
previously been determined in pulse radiolysis experiments, thus a
priori predictions can be made on the efficiency of the intervention and
prevention of gas generation.

***The World\'s Smallest Laser**.* A team of materials scientists and
chemists has built the world\'s smallest laser - a nanowire nanolaser
1,000 times thinner than a human hair. The device, one of the first to
arise from the field of nanotechnology, can be tuned from blue to deep
ultraviolet wavelengths. Zinc oxide wires only 20 to 150 nanometers in
diameter and 10,000 nanometers long were grown, each wire a single
nanolaser. Discovering how to excite the nanowires with an external
energy source was critical to the success of the project. Ultimately,
the goal is to integrate these nanolasers into electronic circuits for
use in \"lab-on-a-chip\" devices that could contain small laser-analysis
kits or as a solid-state, ultraviolet laser to allow an increase in the
amount of data that can be stored on high-density optical disks.

***Polymerization to Make Plastics.*** The discovery of metallocene
catalysts caused major advances in polymer production (e.g.,
polyethylene, polypropylene), the most widespread of synthetic
materials. The ability to control the orientation of each link of a
polymer chain allows control of crystallinity, density, softening point,
and other important properties. A recent improvement in these catalysts
is the synthesis of bimetallic complexes in which two catalytic centers
and two cocatalytic centers are held in close proximity in solution or
adsorbed on surfaces. By altering the nature of the centers, it is
possible to control rate of reactivity, the degree of chain branching,
and plastic rigidity.

***First Ever Chemistry with Hassium, Element 108**.* Element 108 -
hassium - was discovered in 1984. It does not exist in nature but must
be created one atom at a time by fusing lighter nuclei. Recently, the
first experiments to examine its chemical properties were performed by
an international team (German, Swiss, Russian, Chinese and American
scientists) at the Gesellschaft für Schwerionenforschung (GSI) in
Darmstadt, Germany using novel techniques developed at the Lawrence
Berkeley National Laboratory. Energetic magnesium projectiles bombarded
targets of curium, a rare artificial isotope produced and processed at
Oak Ridge National Laboratory. The hassium atoms formed by impacts
between beam and target reacted with oxygen to form hassium oxide
molecules enabling the study of the properties of this new chemical
compound. The chemistry of man-made and heavy elements, particularly
chemistry impacting environmental insults, is of major interest, and
these experiments are a first step for this element.

***Improved Materials for Fuel Cells**.* Major impediments for the
commercialization of fuel cells include the inability to use hydrogen
fuel containing traces of carbon monoxide and the necessity of using
large amounts of expensive platinum catalysts. A novel
ruthenium/platinum catalyst has been produced through a new preparation
method involving spontaneous deposition of platinum on metallic
ruthenium nanoparticles. The resulting catalyst has a higher carbon
monoxide tolerance than commercial catalysts and uses smaller amounts of
platinum.

***Platinum Encrusted Diamond Films**.* Research on new catalytic
electrodes, e.g., for fuel cells, has shown that synthetic diamond thin
films are excellent supports for catalysts because of their corrosion
resistance. The challenge to produce an electrode is to incorporate
nanometer sized platinum and platinum/ruthenium catalyst particles into
the surface structure of the diamond film. Recently, the ability to
incorporate 10 to 500 nanometer diameter particles into the bulk
structure of the films has been demonstrated. These new surface modified
systems may result in significantly improved catalytic activity and
stability, and could have even broader applications in chemical
synthesis, toxic waste remediation, and chemical and biomedical sensors.

***Complex Flow in the Subsurface**.* Recovery of subsurface fluids,
whether oil and gas or contaminants, requires understanding the way
fluids flow within porous and fractured rocks and soil. This is
particularly complicated when there are multiple fluids
(oil-methane-water; water-carbon dioxide). New experiments combined with
theory and computational modeling have tracked the simultaneous flow of
two fluids in fractured and porous media. Flow paths of both fluids are
significantly longer than under single fluid conditions and transport is
very sensitive to differences in fluid structure.

***Complete Plant Genome of the First Model Plant.*** The first complete
sequencing of a plant genome was completed by an international
consortium of researchers from Europe, Japan and the U.S. The DOE was
one of the supporters of the U.S. effort. The sequencing of the genome
of Arabidopsis will provide the information needed to increase food
production in an energy-efficient and environmentally friendly manner,
provide increased wood and fiber production, and increase the use of
plant materials for energy and the production of petroleum-replacing
chemicals.

**Selected FY 2001 Facility Accomplishments**

The four synchrotron radiation light sources and three BES neutron
scattering facilities served 6,982 users in FY 2001 by delivering a
total of 26,476 operating hours to 204 beam lines at an average of 96.1%
reliability (delivered hours/scheduled hours)[^1]. The High Flux Isotope
Reactor at Oak Ridge National Laboratory did not operate in FY 2001 due
to the installation of upgrades. Statistics for individual facilities
are provided below. In one instance, less time was needed for
maintenance activities than was scheduled, so more time was delivered to
users than planned.

The maximum number of total operating hours for these 7 facilities is
estimated to be about 37,100 hours. Most of the BES facilities already
operate close to the maximum number of hours possible for their
facility. The next priority is to support and maintain beamlines and
instruments at the state-of-the art. For the synchrotron radiation light
sources and the neutron scattering facilities, the number of beamlines
and instruments would need to be increased in order to achieve the full
capacity of each of the facilities. Capacity at the light sources could
increase by nearly a factor of two if all beamlines were fully
instrumented. Capacity at the neutron sources could also increase
substantially by upgrading existing instruments and fabricating new
ones.

**The Advanced Light Source (ALS)** served 1,163 users in FY 2001 by
delivering 5,261 operating hours to 37 beam lines at 96.2% reliability
(delivered hours/scheduled hours). The ALS is supported by the Materials
Sciences and Engineering subprogram.

*A new beamline for x-ray microscopy of polymers.* Owing to its
elemental and chemical specificity, x-ray microscopy is a superior tool
for the study of multicomponent polymers. A scanning x-ray microscope
that is specifically optimized to the demands of polymer research is
being commissioned.

*Ambient-pressure photoemission spectroscopy.* The real world of
chemistry, biology, and environmental science is a world that is
frequently wet, hot, and under atmospheric or higher pressures, whereas
experimental measurements are often best done under vacuum with cold
samples. One step toward bridging the gap is the development of a new
experimental chamber for *in-situ* investigation of samples under
ambient conditions.

*Interferometer controls scanning x-ray microscope.* In scanning
microscopy, it is essential to locate and control the position of the
probe over the sample. A control system developed for a scanning x-ray
microscope is able to position the x-ray beam with nanometer accuracy,
so that features in the sample can be studied at the finest spatial
resolution of the instrument.

*Superbend beamlines developed.* To broaden the spectral range of the
Advanced Light Source to cover shorter wavelengths, superconducting bend
magnets were designed. The first two beamlines will be implemented
sequentially over the next year to serve protein crystallographers and
to provide much needed harder x-ray sources for ALS diffraction studies.

**The Advanced Photon Source (APS)** served 1,989 users in FY 2001 by
delivering 4,788 operating hours to 37 beam lines at 95.8% reliability
(delivered hours/scheduled hours). The APS is supported by the Materials
Sciences and Engineering subprogram.

*Storage ring "top-up operation" becomes routine*. After successful
tests with 25% of the scheduled user-beam time dedicated to top-up
operation, the APS is scheduling the majority of future operations for
top-up mode. During top-up operation, injecting a pulse of electrons
once every two minutes holds the stored current constant to 0.2 percent.
This operating mode delivers a constant heat load on x-ray optics and
various accelerator components, thus improving the x-ray beam stability.
It also allows flexibility in operating modes, which are traditionally
limited by the short lifetime of the stored beam. Top-up operation has
significantly enhanced the research capabilities of the APS.

*Two undulators on a single straight section deliver two independent
x-ray beams to users.* For the first time, a novel concept of spatially
separating the beams from two insertion devices placed on single
straight section was realized. This was accomplished by placing the
undulator axes at a small angle with respect to each other. Successful
implementation of this concept enabled 100% efficient utilization of the
delivered beam.

*Low-emittance lattice developed.* Machine studies have successfully
established operating conditions for the APS storage ring with the
horizontal emittance reduced by approximately a factor of two. This
reduces the horizontal source size and divergence of the x-ray beam and
results in at least a factor of two improvement in the overall
brilliance. Initial user results are encouraging and routine operation
with this mode is scheduled for the near future.

**The National Synchrotron Light Source (NSLS)** served 2,523 users in
FY 2001 by delivering 5,556 operating hours to 86 beam lines at 100.0%
reliability (delivered hours/scheduled hours). The NSLS is supported by
the Materials Sciences and Engineering subprogram.

*Polarization modulation spectroscopy for magnetism research.* A new
high-resolution soft x-ray beamline and a phase sensitive detection
system were completed to take advantage of the fast switching capability
of the Elliptically Polarized Wiggler. The new system provides high
sensitivity and enables magnetic field dependent studies.

*Focusing of high energy x-rays with asymmetric Laue crystals*.
Theoretical prediction and experimental verification of a new concept
for focusing of high energy x-rays was demonstrated. This new design
results in a more than 100 fold increase in the photon flux delivered to
the sample. A new monochromator based on this design was constructed and
implemented at the superconducting wiggler beamline for high pressure
and materials research.

*High magnetic field, far-infrared spectroscopy beamline commissioned.*
A new high magnetic field, far-infrared beamline was commissioned with a
far-infrared spectrometer and 16 Tesla superconducting magnet. Combining
this with a high-field magnet system opens up new opportunities for
measuring electron spin resonance (ESR), cyclotron resonance, and other
magneto-optic effects in solids.

*X-ray optics for microbeam diffraction, elemental mapping, and high
pressure research developed.* A new system for micro-focusing of x-rays
was implemented, achieving a focus of 3 microns (vertical) by 9 microns
(horizontal). The system has been used in the study of bone diseases,
materials under high pressure, and semiconductors.

*High gain harmonic generation (HGHG) free electron laser (FEL) achieves
saturation.* By frequency multiplying and amplifying a seed laser
signal, an HGHG FEL imposes the properties of the laser onto the FEL
output beam. In a demonstration, light at long wavelength was frequently
doubled. Full characterization of the FEL light and its harmonics agreed
with theory and demonstrated the utility of an HGHG FEL for producing
intense coherent light pulses.

**The Stanford Synchrotron Radiation Laboratory (SSRL)** served 907
users in FY 2001 by delivering 4,539 operating hours to 25 beam lines at
94.9% reliability (delivered hours/scheduled hours). The SSRL is
supported by Materials Sciences and Engineering subprogram.

*Stanford-Berkeley synchrotron radiation summer school.* The first
Stanford-Berkeley summer school on synchrotron radiation and its
applications was held with 36 students from a diverse range of
scientific fields. The goal was to introduce young scientists to the
fundamental properties of synchrotron radiation and the understanding
and use of several techniques, including spectroscopy, scattering, and
microscopy.

*New actinide facility commissioned.* Synchrotron-based measurements are
a crucial part of chemical and materials research programs involving
radionuclides and radiologic materials. In order not to limit the scope
of experiments that can be performed, a radiologic sample analysis
facility has been integrated into a modern synchrotron beamline. This
combination insures safe handling of actinide and other radiology
materials and also provides state-of-the-art measurement capabilities
that have proven extremely useful in remediation efforts.

*Materials science small angle x-ray scattering beamline facility
completed.* The materials science small and wide-angle x-ray scattering
station is now in full user operation. The integrated beamline and
experimental equipment facility allows for studies of weakly scattering
systems, such as dilute polymer solutions.

*Microfocus optics system for X-ray micro-spectroscopy.* An experimental
apparatus employing tapered metal capillary optics for conducting X-ray
micro-spectroscopy is now in operation. This capability allows X-ray
micro-spectroscopy experiments in the materials, biological, and
environmental sciences.

*Successful 3 GeV injector test.* The SPEAR injector was successfully
run at 3 GeV, proving that it is ready to provide at-energy injection
for SPEAR3. The 3 GeV test came toward the end of the two-year Injector
Upgrade Accelerator Improvement Project, in which power supplies,
magnets, and diagnostics were upgraded to insure reliable 3 GeV
operation. At-energy injection will improve SPEAR3 performance by
providing better fill-to-fill orbit reproducibility and thermal
stability.

*RF waveguide dampers improve beam stability and lifetime.* RF waveguide
dampers were installed in the two radio frequency (RF) waveguides in the
SPEAR storage ring to eliminate high frequency oscillations excited by
the electron beam in the RF cavity/waveguide system. The dampers not
only eliminated the instabilities but they allowed the use of operations
parameters that gave a 20% improvement in the electron beam lifetime.

**The Intense Pulsed Neutron Source (IPNS)** served 240 users in FY 2001
by delivering 3,968 operating hours to 13 beam lines at 102.6%
reliability (delivered hours/scheduled hours). The IPNS is supported by
the Materials Sciences and Engineering subprogram.

*IPNS hosts the national neutron and x-ray scattering school.* In August
2001, Argonne National Laboratory again hosted the two-week National
School on Neutron and X-Ray Scattering. The school continues to attract
outstanding graduate students and post-doctoral appointees with 179
applications for the 60 available positions.

*Upgrade of IPNS instruments.* The High Resolution Medium Energy Chopper
Spectrometer (HRMECS) instrument was completely upgraded and a chopper
was added to the General Purpose Powder Diffractometer (GPPD). The
HRMECS upgrade included the complete overhaul of data collection/control
software and hardware, addition of position-sensitive detectors at low
scattering angles and improved neutron choppers. The T0 chopper on GPPD
blocks high energy neutron from entering the diffractometer.

*Auto-anneal capabilities added to moderator system.* Regular annealing
required for IPNS's unique ultra-cold moderator has been accomplished by
installing a system that automatically anneals the solid methane
moderator every three days. This automation allows for reduced manpower
and improved operation of the IPNS target moderator assembly.

**The Manuel Lujan Jr. Neutron Scattering Center at the Los Alamos
Neutron Science Center** LANSCE served 122 users in FY 2001 by
delivering 2,364 operating hours to 6 beam lines at 82.0% reliability
(delivered hours/scheduled hours). The Lujan Center is supported by the
Materials Sciences and Engineering subprogram.

*HIPPO diffractometer commissioned.* Following three years of design and
construction, the recently completed HIPPO (High Pressure, Preferred
Orientation) diffractometer took its first neutron-beam-related
diffraction pattern on a sample of nickel on July 7, 2001. The
scientific thrust of this new state-of-the-art spectrometer is the
investigation of dynamic processes in heterogeneous bulk materials in a
variety of environments.

*SMARTS will provide new capabilities in materials research.* SMARTS, a
third generation neutron diffractometer for the study of polycrystalline
materials, received its load frame and furnace, which were successfully
tested onsite during 2001. SMARTS is scheduled to receive first beam in
August 2001, followed by commissioning through the remainder of the
year.

*BES partners on new institutional instruments.* Three institutionally
funded instruments, ASTERIX, PHAROS, and IN500 were supported in part
under the auspices of BES. ASTERIX produces a highly polarized intense
beam of cold neutrons that has a very large cross section and covers a
wide wavelength range while minimizing the fraction of the neutron beam
that is not used. PHAROS, a high-resolution chopper spectrometer, is
designed for low-angle studies. IN500 is a cold neutron time-of-flight
spectrometer, which will offer all the advantageous capabilities of
reactor-based instruments.

*Instrument performance improves with use of new chopper technology.*
All of the Lujan Center\'s new instruments and some of the existing
instruments have enjoyed dramatic improvements in chopper technology in
FY 2001. These performance improvements in two technical areas, timing
reference generators and chopper controls, now enable the accelerator
and all neutron choppers to run as slaves of the master timing
generator. This success in chopper technology has drawn the attention of
several other spallation neutron facilities and has redefined the timing
specifications for the Spallation Neutron Source.

*Upgrades to small-angle scattering instrument.* A new frame-overlap
chopper was procured and installed, which enables the small-angle
scattering instrument, LQD, to make full use of the higher flux it
enjoys from the hydrogen moderator installed over the last two years.
Recent additions to LQD also include a gravity-focusing device, which
compensates for gravitational drop, especially for slow neutrons.

*Upgrades to SPEAR improve instrument performance.* SPEAR (Surface
Profile Analysis Reflectometer) is used for determining chemical density
profiles at solid/solid, solid/liquid, solid/gas, and liquid/gas
interfaces. Upgrades to SPEAR during 2001 included the installation of
shutter hardware to reduce closure time, and additional automation of
flight-path components. For better performance, an evacuated flight
path, and two digital chopper controllers were added. In addition, a new
collimation system, together with improved software, allowed for the
first real-time reflectivity measurements. These upgrades were made to
make the instrument user-friendlier.

**The High Flux Isotope Reactor (HFIR)** served 38 users in FY 2001 by
delivering 8 operating hours for materials irradiation and institutes
that utilize the transplutonium program and medical isotopes. The
reactor was shut down at 8:00 a.m. on October 1, 2000, for the scheduled
replacement of the beryllium reflector and installation of upgrades and
remained shutdown for the remainder of the year. The HFIR is supported
by the Materials Sciences and Engineering subprogram.

*Installation of new components enhances scientific capabilities at
HFIR.* Many of HFIR's internal components have been replaced with new,
upgraded components that will significantly enhance its neutron
scattering research capabilities without diminishing its
isotope-production or material-testing capabilities. Replaced components
include the beryllium reflector, its support structure, and three of the
four neutron beam tubes. Beam intensity for some instruments is expected
to be three times that of the original design.

*Cold Source Project progress.* The moderator vessel has been fabricated
and has passed acceptance pressure tests at room and liquid-nitrogen
temperatures.

*Spectrometers for cold neutron research.* The cold source to be
installed at HFIR will provide long wavelength neutron beams that are
unsurpassed worldwide. Instrumentation has been designed to make optimum
use of the cold neutron beams. Instruments include small angle
spectrometers for measurements on large-scale structures, reflectometers
for the study of surface phenomena, and triple-axis spectrometers for
the determination of low-energy excitations.

*Spectrometers for thermal neutron research.* The larger beam tubes and
new mochromator drums installed at HFIR will permit considerable gains
in intensity for the thermal neutron spectrometers, by as much as a
factor of five.

**The Combustion Research Facility (CRF)** is supported by the Chemical
Sciences, Geosciences, and Energy Biosciences subprogram.

*New capabilities.* The CRF provides a primary interface for the
integration of BES programs with those of DOE\'s Offices of Energy
Efficiency and Renewable Energy and Fossil Energy related to combustion
by collocating basic and applied research at one facility. Three
laboratories were completed. The particle diagnostic laboratory can now
generate flames with controllable fuel and oxidizer feeds to develop a
fundamental understanding of small particle formation from combustion
sources. A time-resolved fourier transform spectrometer for chemical
kinetics and dynamics studies is now available in the kinetics and
mechanisms laboratory. Related to applied research, the investigation of
a novel engine combustion concept is being conducted in the new
homogeneous-charge, compression-ignition engine laboratory.

## Selected FY 2000 Scientific Highlights/Accomplishments

**Materials Sciences Subprogram**

***Magnetism at the atomic scale.*** When information is written to a
computer hard drive, local magnetic moments associated with atoms in a
small region of the surface reverse direction like sub-microscopic
compass needles. A new theory has helped explain these dynamical
processes. This work recently received the Gordon Bell Award for the
fastest real supercomputing application and was named to the
Computerworld Smithsonian 2000 collection for being the first
supercomputing application to surpass one teraflop.

***Functional nanostructured materials that replicate natural
processes.*** A newly developed class of nanostructured materials can
selectively filter molecules by their size and chemical identity. These
remarkable materials are made from a solution of molecular building
blocks that spontaneously arrange themselves into a porous solid as the
solvent evaporates. This achievement involved creating the
self-organizing precursors, controlling the pore size, and employing a
novel evaporation process that promotes self-assembly. These materials
hold the promise for significant applications. For example, in the
future we may wear "breathing" fabrics that block hazardous chemicals
while admitting benign species like oxygen.

***The Library of Congress on a single disk?*** The vision that
information can be written and erased near the single molecule limit has
been realized for the first time. Disordering and re-ordering tiny
regions of a thin film show promise for storing a million times more
information than with today\'s computer disks with no increase in space.
The film is made of organic material and supported by graphite. It is so
thin that 40,000 layers would be only as thick as a sheet of paper. By
exposing the film to voltage pulses with a scanning tunneling
microscope, nanometer-sized regions can be switched from crystalline to
disordered, increasing their ability to conduct electricity by 10,000
times. Each tiny region is one bit of information, not much bigger than
a single molecule of the film.

***Analyses of nanocrystals using coherent (laser-like) synchrotron
radiation.*** A powerful new x-ray diffraction method for characterizing
the structure of nanocrystalline solids has been developed. Tailoring
nanocrystalline properties for specific applications depends critically
on detailed knowledge of three-dimensional structure. Traditional x-ray
diffraction methods are inadequate; however, coherent x-ray diffraction
patterns of gold nanocrystals show surface facets, fringes due to
interference among facets, nanocrystal lattice distortion, and,
ultimately, equilibrium nanocrystal shape.

***Ion-implantation for strong metal-ceramic bonds**.* Ceramics are hard
and corrosion resistant but fracture easily. Metals resist fracture but
are not as wear or corrosion resistant as ceramics. Coating a metal with
a ceramic is a way to improve both. However, current coating
technologies can degrade the performance of metals. A new approach has
been successfully developed that employs ion-beam intermixing of the
coating with the metal from collision cascades, which are microscopic
(nanometer-sized) "hot-zones" formed along the ion track. Since the
heating in collision cascades is very short and localized, macroscopic
heating of the metal does not occur. A patent has been filed using this
new approach to improve hip, knee, and dental prosthetic devices. Ion
implantation is used to coat the bone mineral (hydroxyapatite) on
titanium starting with a high density layer bonded well to the titanium
and changing progressively toward a porous bone mineral outer surface
that promotes bone growth and bonding to bone.

***Long-term storage of plutonium.*** Worldwide, nuclear energy
production and defense programs have created 1,350 metric tons of
plutonium. Because plutonium is radiotoxic and has a long half-life
(24,500 years), a long-term storage solution must immobilize plutonium
in materials that are resistant to radiation damage for millennia. Using
heavy-ion irradiation, advanced characterization techniques, and
computer simulation methods, researchers have discovered that highly
durable gadolinium zirconate can lock plutonium into its structure while
remaining resistant to radiation damage for millions of years.

***Boron doping of silicon semiconductor devices \-- faster, lower-power
computing.*** Boron doping of silicon improves electrical conductivity
and other important aspects of silicon device performance. A fifty-fold
increase in active boron doping \-- far above nature's maximum of 0.01
percent \-- has been achieved using a new process involving atomic
hydrogen. Resulting ultra-highly doped silicon layers provide
self-aligned \"metallic\" contacts, improve semiconductor devices,
eliminate etching steps in device fabrication, reduce manufacturing
costs, and minimize the use of toxic etching gases and chemicals.

***Seeing electrons.*** A novel, quantitative, and highly sensitive
method has been developed to image and measure the distribution of
valence electrons, which are responsible for chemical bonding and the
transport of electrical charge in solids. This new technique, combining
imaging and diffraction in the electron microscope, was used to reveal
the spatial distribution of valence electrons in complex structures of
high-temperature superconductors. The ability to directly observe and
measure valence electron distributions with atomic scale resolution will
greatly help in the search for better superconductors, ferroelectrics,
and semiconductors.

***Fluctuation microscopy.*** Fluctuation microscopy, a new discovery,
challenges the common perception that glassy materials have no
organization. Fluctuation microscopy relies on the ability of the
electron microscope to measure diffraction from tiny volumes (\~1000
atoms). It is based on detailed computational simulations coupled with
computer-assisted statistical analysis of multiple electron images. It
has required development of advanced image-detection methods. In one of
the first applications of this method, studies of amorphous silicon and
germanium show that both are highly organized over distances of tens of
atoms, even though other measurement techniques see these atoms as
completely random. This finding is critical to improving the ability of
amorphous solar cells.

***A smart transistor.*** A breakthrough in developing the world\'s
smartest transistor has been accomplished. Germanium-based transistors
using a new ferroelectric dielectric would be "smart" devices capable of
remembering their state. The heart of this new scientific advance is the
understanding of the relationship between polarization and
microstructure and how to control it. This breakthrough offers enormous
potential for energy savings in a myriad of electronic sensors and
devices as no power is necessary to maintain a given on/off state. A
low-power, gigabyte chip could thus serve as a computer hard drive.

***Design of semiconductors with prescribed properties**.* A theoretical
method has been invented by which one can first specify the properties
desired in a semiconductor and then work backward to predict the
structure of the material that will show those properties. This work was
featured in *Fortune Magazine*.

**Chemical Sciences Subprogram**

***Direct measurement of chemical reactions in turbulent flows.*** Long
known for their dramatic advancements in laser instrumentation for
monitoring gas-phase reactions and chemically reacting flows, scientists
at the Combustion Research Facility have for the first time monitored
multiple flame species directly and simultaneously. These measurements
provide a powerful test of combustion models that could lead to improved
combustion efficiency.

***Dynamics of a single molecules.*** Reactions of single molecules have
been observed by monitoring molecular fluorescence using newly developed
experimental methods, thus separating the effects of the motion of one
molecule from the ensemble motion of the molecule in its environment.
The dynamics of a single molecule have been shown to be significantly
different from motion in an ensemble, and should lead to the development
of new theories for predicting chemical reactivity.

***Blinking quantum dots.*** Quantum dots \-- nanometer-size particles
in which electrons are confined in a relatively small volume \-- have
recently been shown to emit light at multiple wavelengths, blinking on
and off on a time-scale of seconds. This remarkable behavior, attributed
to luminescence from different electronic states, has potential
applications for optical logic and photonics and may one day lead to
nano-scale computers and/or portable analytical instrumentation.

***Generation of laser-like x-ray beams.*** Combining state-of-the-art
ultrafast laser systems with evolutionary computer algorithms has led to
a dramatic new demonstration of the controlled generation of coherent
x-rays. This represents an important new source of ultrafast, coherent
soft x-rays for studies of materials properties and chemical physics.

***Biomolecular photobatteries.*** Voltages have been measured from a
single photosynthetic reaction center \-- the five nanometer wide
molecular structure in green plants that captures solar energy and
converts it into electrical energy. The reaction center may be thought
of as a tiny photobattery. The reaction center functions as
nanometer-sized diodes with possible applications to molecular scale
logic devices and computers.

***Radiation induced chemistry.*** Solid particles have been found to
enhance the effects of water radiolysis and the resulting production of
hydrogen. Furthermore, gas bubbles form on the particles and that
impedes the continuous, safe release of hydrogen from the suspension.
These results may provide an explanation for the "burps" in storage
tanks containing aqueous suspensions and radioactive material.

***Plutonium chemistry in the environment**.* Using newly constructed
beamlines at the BES synchrotron radiation light sources, scientists are
now able to study small quantities of radioactive materials. X-ray
absorption studies on plutonium-containing soils from Rocky Flats
revealed that the plutonium is predominantly present as the solid oxide,
PuO~2~, a form substantially less mobile in soil and ground water than
other possible forms. This result demonstrates that the plutonium will
remain stable and has led to substantial cleanup cost savings.

***Actinide supramolecular complexes**.* Researchers have for the first
time built a supramolecular actinide complex. Supramolecular complexes
are molecules that are built from smaller subunits, yet retain their own
distinct molecular properties. While there may be future applications in
separation science and catalysis, the current worldwide effort in
supramolecular chemistry is to understand the principles that govern
assembly of such molecules.

***Molecular theory of liquids**.* A molecular theory for the liquid
state, which has eluded scientists for years, has now been developed.
This provides new opportunities in one of the most important areas for
process engineering and one of its most perplexing problems - the
prediction of liquid-gas equilibria based on the well-known properties
of molecules.

**Engineering and Geosciences Subprogram**

***Engineering at the nanoscale.*** Using nanoscale devices in
real-world engineered systems is one of the greatest challenges facing
nanoscale research. A portfolio of research activities explores how to
engineer at the nanoscale. Recent activities include the development of
physics-based models to represent crack initiation as a nanoscale
phenomenon; studies of the frictional response of nanochains; electric
charge transfer in semiconductor nanostructures; nanoscale quantum-dot
self assembly using DNA templates; and the integration of nanoscale
biomotors with mechanical devices. In this last activity, researchers
constructed integrated nanoscale devices that are powered by
biomolecular motors and fueled by light. In one such system, a protein
from a photosynthetic bacterium generates an electrochemical gradient
across an artificial membrane system. This system is chemically closed,
enabling the motors to be continuously supplied with fuel using a total
light collection area less than 400 square nanometers.

***Geosciences imaging from the atomic scale to the kilometer scale.***
Advances in geosciences imaging were demonstrated this year at a variety
of disparate length scales. At the smallest length scale, the GeoCARS
beamline at the Advanced Photon Source was used to examine the
interaction of liquid water with alumina as a model for understanding
aluminum containing minerals such as clays. Unlike other techniques used
to characterize surfaces, the new beamline can study wet crystal
surfaces. The result showed a significant change from the experiments
using dry surfaces and will help researchers understand water-solid
interactions in nature at the atomic level. At an intermediate length
scale, researchers are using advanced laser scanning confocal microscopy
to image, reconstruct, and characterize fluid flow through pores and
cracks. Predicting the magnitudes and directions of flow in earth
material is critical in performance assessment of oil and gas
reservoirs. Finally, at the largest length scales, researchers are using
specially instrumented regions in an earthquake zone to help model and
improve geophysical imaging on the kilometer scale.

***Biogeochemistry.*** It is increasingly evident that living processes
play a fundamental role in determining the geochemistry of groundwater,
near-surface sediments, and deeper rocks. Microbes affect the weathering
of rocks and minerals, and microbial metabolism affects the accumulation
of heavy metals in soils or their release to groundwater. These and
other processes determine how soils, sediments, and ore bodies form and
how water quality is affected. Work identifying how microbes affect the
fate of zinc released to groundwater percolating through lead-zinc mines
and other biogeochemistry work recently led to the award of MacArthur
Foundation Fellowship to a BES supported researcher. Biogeochemistry,
which links three BES subprograms, is expected to play an increasingly
important role in addressing DOE missions.

**Energy Biosciences Subprogram**

***Completion of the gene sequence of* Arabidopsis thaliana*, the first
plant genome.*** *Arabidopsis thaliana*, a small weed belonging the
mustard family, became the world's "model" plant owing to its small
physical size, small genome size, low level of junk and repetitive DNA,
short life cycle, large number of mutations, and ease in genetic
analysis. An international collaboration involving scientists from the
U.S., Europe, and Japan announced the completion of the complete
sequence of this plant genome in December 2000. The *Arabidopsis* genome
is entirely in the public domain, making the results available to
scientists worldwide. The Energy Biosciences subprogram has been a
partner in this project since its inception; support for research on
*Arabidopsis* dates to the early 1980s.

***Snapshot of a light-driven pump.*** Sunlight causes the
bacteriorhodopsin protein to change shape, and in the process transport
protons across a membrane to provide chemical energy. X-ray
crystallographic structure determinations of this light-driven proton
pump captured for the first time the molecule frozen mid-stroke of this
shape modification. This novel view of the intermediate conformation
enables us to see how biological nanostructures capture and transform
energy.

**Selected FY 2000 Facility Accomplishments**

The four BES synchrotron radiation light sources served 6,009 users in
FY 2000 by delivering a total of 19,854 operating hours to 184 beam
lines at an average of 99.5% reliability (delivered hours/scheduled
hours). The three BES neutron scattering facilities served 524 users in
FY 2000 by delivering a total of10,395 operating hours to 34 beam lines
at an average of 94.7% reliability (delivered hours/scheduled hours).
Statistics for individual facilities are given below.

"Users" are defined by BES as researchers who conduct experiments at a
facility (e.g., received a badge) or receive primary services from a
facility. An individual is counted as one user per year regardless of
how often he or she uses a given facility in a year. "Operating hours"
are the total number of hours the facility delivers beam time to its
users during the Fiscal Year. Facility operating hours are the total
number of hours in the year (e.g., 365 days times 24 hour/day = 8,760
hours) minus time for machine research, operator training, accelerator
physics, and shutdowns (due to maintenance, lack of budget, faults,
safety issues, holidays, etc.).

**The Advanced Light Source (ALS)** served 1,036 users in FY 2000 by
delivering 5,367 operating hours to 34 beam lines at 95.0% reliability
(delivered hours/scheduled hours). The ALS is supported by the Materials
Sciences subprogram.

*New technique for improved storage-ring stability.* The electron beam
parameters in the storage ring determine x-ray beam lifetime and
stability. Using a mathematical technique, accelerator physicists have
understood the strength and location of harmful resonances that cause
irregular, chaotic electron behavior leading to loss of electrons from
the beam.

*Third-harmonic cavities enhance beam lifetime.* The electron beam
lifetime in a synchrotron-radiation source determines how long users can
record data before being interrupted when accelerator operators
replenish the train of short bunches that make up the beam. A desirable
way to increase the lifetime is to lengthen the bunches. Five new
third-harmonic cavities accomplish the bunch lengthening and have
increased electron beam lifetime increased by about 50%.

*X-ray science possible at femtosecond speeds.* X-ray experiments to
study physical, chemical, and biological processes that occur on a time
scale of one molecular vibration (typically 100 femtoseconds) are an
emerging area of research. Three developments at the ALS brought x-ray
science into the femtosecond realm. First, researchers developed a
high-speed x-ray detector (a streak camera) with a picosecond time
resolution. Second, researchers showed how to use a femtosecond laser to
\"slice\" tiny slivers from the circulating electron bunches in the
storage ring and use them to produce pulses of synchrotron radiation
lasting just 300 femtoseconds. Finally, accelerator physicists devised
an arrangement of magnets that allow a narrow-gap undulator optimized
for the production of femtosecond x rays to be installed in the storage
ring.

*Undulator has complete polarization control.* The elliptically
polarizing undulator (EPU) in the ALS is now in full user operation with
a high-resolution beamline to provide state-of-the-art performance. This
capability opens up many new experimental possibilities in polymer,
biophysics, and magnetism research all without rotation of the sample.

*Upgrades improve photoemission electron microscopy.* By imaging the
photoelectrons emitted from a sample with high spatial resolution, the
photoemission electron microscope is an ideal tool for combining
spectroscopy with variable polarization microscopy in the study of
materials ranging from magnetic materials to polymers. The performance
and sample-preparation facility of this instrument have been upgraded,
making possible new experiments, such as probing the magnetic roles of
the different elements in multilayer structures of the type under
development for magnetic memory and data storage.

*A facility for sub-micron x-ray diffraction developed.* Many properties
depend on behavior within individual grains and on the details of
grain-to-grain interactions. The ALS has pioneered the technology needed
for x-ray micro-diffraction and its application to thin-film stress
analysis. The system is capable of measuring structural parameters from
grains as small as 0.7 micron. The technique is starting to play a major
role in many materials projects, from stress-induced cracking of
indented high-strength materials to stress in magnetic thin films.

**The Advanced Photon Source (APS)** served 1,527 users in FY 2000 by
delivering 4,724 operating hours to 34 beam lines at 93.6% reliability
(delivered hours/scheduled hours). The APS is supported by the Materials
Sciences subprogram.

*3-D imaging in real time.* A real-time, three-dimensional x-ray
microtomography imaging system that can acquire, reconstruct, and
interactively display rendered 3-D images of a sample at
micrometer-scale resolution within minutes has been developed. This
system could bring better understanding of an array of physical
processes, ranging from failure in microelectronic devices to growth and
depletion processes in medical samples.

*Novel x-ray microprobe developed.* The magnetic contribution to the
cross section for x-ray scattering is of significant interest. A
technique has been developed that combines microfocusing x-ray optics
with Bragg-diffracting phase retarders to produce a circularly polarized
x-ray microprobe. This will enable a wide variety of magnetic scattering
experiments in applied fields like magnetic materials and
superconducting compounds.

*New beam chopper improves time-resolved experiments.* A new beam
chopper has been developed for time-resolved experiments. The time
window of 10 nanoseconds enables time-resolved experiments in
condensed-matter physics, atomic physics, and biological science.

*Beam-position monitor improvements started.* Significant upgrades have
been made to the particle beam and x-ray beam position measurement
systems. Further progress is expected when these changes are
incorporated in all of the beamlines at the APS. This state-of-the-art
improvement in beam stability will provide the APS users with more
efficient beamlines and the capability of working with smaller samples
and increased measurement resolution.

*Storage-ring "top-up" operations developed.* The APS is the first
facility to implement \"top-up\" filling of the storage with electrons
during normal operations. During 136 hours of top-up operation, the
stored current was held constant to about two parts per thousand by
injecting a pulse of electrons once every two minutes. This resulted in
improvements in x-ray beam stability. Ultimately, top-up filling will be
the routine operating mode of the APS.

*Record FEL SASE achieved.* Using the Low-Energy Undulator Test Line
(LEUTL) and the injector linac, an experimental verification was
obtained of the self-amplified spontaneous emission (SASE) process for
530 nm light. More recently, saturation of the SASE process at a power
level 10,000,000 times higher than the light produced by a single
undulator insertion device was verified. These experiments are viewed as
necessary experimental milestones for achieving an x-ray free-electron
lasers.

**The National Synchrotron Light Source (NSLS)** served 2,551 users in
FY 2000 by delivering 5,620 operating hours to 90 beam lines at 112.9%
reliability (delivered hours/scheduled hours). The NSLS is supported by
the Materials Sciences subprogram and the Chemical Sciences subprogram.

*New optical polarizer.* A newly developed quadruple-reflector optical
polarizer efficiently converts VUV light from linear to either
left-circular or right-circular polarization. This polarizer expands the
capability the U5UA beamline in the area of ultra-thin magnetic films.

*High-resolution photoelectron spectrometer.* A high resolution
photoelectron spectrometer was installed on the U13UB beamline, and has
already produced new physical insights into the electronic structure of
high temperature superconductors.

*Infrared beamlines revitalized.* The 10 year-old infrared
microspectrometer at U10B beamline was replaced with a state-of-the-art
continuum microscope and advanced Fourier transform infrared
spectrometer. The system has been used for the study of interplanetary
materials, biological tissues, corrosion, and materials formed at high
pressure. Also, the beam delivery optics for the U12IR beamline were
rebuilt to provide infrared radiation to a new high-resolution
spectrometer. This spectrometer will be used for magnetospectroscopy
studies of materials such as LaMnO~3~.

*Fluorescence microscopy.* For the first time, an infrared microscope
has been modified such that fluorescence sample visualization and
infrared microspectroscopic analysis can be performed simultaneously.
This unique combination is a valuable analysis tool for probing the
chemical composition of materials.

*Advanced x-ray detector array enables study of trace elements.* X-ray
absorption spectroscopy of trace elements in samples poses a serious
detection problem. The detector technology developed for high-energy
physics applications was used to produce a 100-element energy-resolving
detector array for use on an NSLS beamline.

*Advanced x-ray detector system developed.* One of the ways in which
diffraction experiments can be made more efficient is to detect the
entire diffraction pattern with high resolution. In order to accomplish
this, a novel curved cylindrical detector was developed. In addition, a
highly-parallel readout system was developed that is capable of
processing events 10 times faster than before.

*Low-cost monochromator, low-maintence spectrometer.* A simple device
that consists of a monolithic silicon diffracting element is near- zero
maintenance and almost adjustment free. It is now used on five NSLS
beamlines; several more such detectors will be installed at NSLS and at
other facilities. The new device removes need for ultra-fine mechanisms
that contribute to most of the cost of such an instrument and makes
x-ray monochromators difficult to control.

*Digital feedback system improves storage ring stability.* Meeting the
needs of the large population of NSLS users for high quality photon
beams requires an extremely stable electron orbit. To that end, digital
orbit feedback systems to replace the original analog ones were designed
in both the VUV and the X-ray rings. The main advantage of switching to
a digital architecture is the ability to use a higher number of beam
position monitors to achieve a better match between disturbances on the
beam and corrective action by the feedback system. The digital global
orbit feedback system was put into operations in the VUV ring in August
2000. Implementation of the digital orbit feedback system on the X-ray
ring is expected in FY 2001.

**The Stanford Synchrotron Radiation Laboratory (SSRL)** served 895
users in FY 2000 by delivering 4,143 operating hours to 26 beam lines at
96.8% reliability (delivered hours/scheduled hours). The SSRL is
supported by Materials Sciences subprogram and the Chemical Sciences
subprogram.

*Reliability of SPEAR improved.* The reliability of the injector was
improved by rebuilding the regulation of power supplies in the beam
transport line. This contributed to shorter filling times, and,
consequently, to longer beam times available to the users.

*Quality of the photon beam enhanced.* Stable photon beam intensity is
one of the requirements for performing demanding synchrotron radiation
experiments. Accelerator physics studies determined that one type of
beam noise was due to the excitation of high order electro-magnetic
modes in the accelerating cavities. To alleviate this problem, waveguide
dampers were installed in the radio-frequency accelerating system. As a
consequence, SPEAR operates more reliably and the beam stability is
improved.

*SSRL beam line systems modernized.* Six beam line stations were
upgraded to the SSRL standard data acquisition system and control
software. This greatly increases reliability while reducing user
training time, spares requirements, and staff support requirements.

*High magnetic field x-ray scattering station commissioned.* A new high
magnetic field end station incorporating a 13 Tesla superconducting
magnet was constructed and commissioned on SSRL's premiere x-ray
scattering beam line, BL7-2. This facility is one of the few facilities
in the world that enable state-of-the-art x-ray scattering experiments
in high field environments. The unique matching of a versatile,
high-field magnet with an intense synchrotron x-ray source allows
scientists to unravel the properties of these new materials. Eventually,
the fundamental understanding that will be derived from this research
will lead to higher performance sensors and magnetic storage devices.

*Photoemission beamline improved for higher throughput and resolution.*
The high-resolution angle resolved photoemission beam line station 5-4
has been used to study the fundamental mechanisms of high temperature
superconductivity and improvements in FY2000 have brought the station to
new levels of performance. The upgrades include a new primary focusing
mirror and an angle mode option to the photoelectron energy analyzer
greatly improving throughput.

*Molecular environmental science facility commissioned.* The importance
of molecular based research in the environmental area is increasing in
importance due to the emergence problems ranging from environmental
remediation at the DOE weapons labs, to long term storage of nuclear
waste, to basic questions concerning molecular interactions of
pollutants at the surfaces of soils. Beam line station 11-2 has been
optimized for x-ray absorption studies of samples in a variety of states
and under dilute field conditions. The station also includes
capabilities for small spot analysis as well as specialized facilities
for the safe handling and analysis of radioactive materials such as
soils contaminated with actinides or wastes from nuclear storage sites.

*New research and training gateway program initiated.* A Gateway pilot
program involving SSRL and the University of Texas at El Paso (UTEP) is
providing training and research opportunities targeted toward Mexican
and Mexican American students. In FY 2000, a group of 16 UTEP students
and staff underwent training and carried out experiments on four
separate beam lines.

**The Intense Pulsed Neutron Source (IPNS)** served 230 users in FY 2000
by delivering 3,842 operating hours to 15 beam lines at 101.6%
reliability (delivered hours/scheduled hours). The IPNS is supported by
the Materials Sciences subprogram.

*Upgrade of QENS instrument.* The quasielastic neutron scattering (QENS)
instrument was compleely upgraded. This instrument is used for
measurements that determine the diffusion rates of both molecular
rotation and translation on the typical time-scales of simple liquids,
adsorbates etc. QENS is also capable of measuring vibrational
excitations up to a few hundred meV, providing access to both external
and internal vibrational modes for hydrogenous systems.

*IPNS hosts second National Neutron and X-Ray Scattering School.* During
the two-week period of August 14-26, 2000, Argonne National Laboratory
once again hosted the National School on Neutron and X-Ray Scattering.
The success of the previous year was so overwhelming that additional
funds were provided by BES to increase the size of the school from 48 to
60 graduate students. Funding was also provided by the National Science
Foundation. This school fulfills a continuing need for training graduate
students in the utilization of national user facilities. The formal
program included 32 hours of lectures given by an internationally known
group of scientists recruited from universities, national laboratories
and industry.

**The Manuel Lujan Jr. Neutron Scattering Center at the Los Alamos
Neutron Science Center** LANSCE served 25 users in FY 2000 by delivering
736 operating hours to 7 beam lines at 78.8% reliability (delivered
hours/scheduled hours). LANSCE was down for installation of upgrades and
safety shutdowns in FY 2000. The Lujan Center is supported by the
Materials Sciences subprogram.

*Neutron flux increased.* The Lujan Center is the first spallation
neutron source to exploit the increased neutron flux provided by coupled
moderators. A new coupled liquid-hydrogen moderator provides an increase
of approximately 2.5 times over the previous decoupled moderator. Both
the small-angle diffractometer, LQD, and the Surface Profile Analysis
Reflectometer, SPEAR, benefits from this increased flux at Lujan. The
increase in flux is a result of the interaction of the moderator, the
reflector surrounding the moderator, and the lack of decouplers.

**The High Flux Isotope Reactor (HFIR)** served 269 users in FY 2000 by
delivering 5,817 operating hours to 12 beam lines at 92.9% reliability
(delivered hours/scheduled hours). The HFIR is supported by the
Materials Sciences subprogram and the Chemical Sciences subprogram.

*Cold source progress.* Work continues on the development of the
nation\'s highest-intensity cold neutron source. This cold source, which
will be comparable in intensity to the world\'s best at the Institut
Laue--Langevin (ILL) in Grenoble, France, will support four neutron
guides and instruments. The cold source building and refrigeration plant
have been completed, and the guides and cold-source moderator vessel are
in fabrication.

**The Combustion Research Facility (CRF)** is supported by the Chemical
Sciences subprogram.

*New capabilities brought on line.* The CRF provides a primary interface
for the integration of BES programs with those of DOE's Office of Energy
Efficiency and Renewable Energy and Office of Fossil Energy related to
combustion by collocating basic and applied research at one facility.
Phase II of the CRF more than doubled the laboratory floor space to
37,000 square feet, increasing the number of labs to 37. The new wing
houses unique instruments, such as picosecond lasers for diagnosing
molecular energy transfer. The turbulent flame diagnostics laboratory,
which has become an international standard, has been expanded to
accommodate two simultaneous and independent experimental stations for
visitors. The new laser-imaging laboratory has also been expanded to
include several flame geometries with controlled, reproducible flow
structures. New staff members have been or are being hired in
theoretical chemistry, computer science, and experimental chemical
dynamics.

## Selected FY 1999 Scientific Highlights/Accomplishments

***Serendipitous Applications of Research in the Physical Sciences to
the Life Sciences.*** It has long been recognized that tools and
concepts developed in the physical sciences can revolutionize the life
sciences. One need only consider the impact of x-ray synchrotron
radiation and MAD (multiple wavelength anomalous diffraction) phasing on
macromolecular crystallography; both were developed within the BES
program. In FY 1999, many of the annual BES program highlights
illustrate the rapidity with which advances in the physical sciences are
impacting the life sciences. Two examples are given here. First, new
techniques of nuclear magnetic resonance (NMR) are being used to study
the molecular structures of solid protein deposits implicated in brain
diseases such as Alzheimer\'s Disease and BSE (Mad Cow Disease); both
diseases involve the transformation of normal, soluble proteins in the
brain (whose structure is known) into fibers of insoluble plaque (whose
structure is largely unknown). Second, a nano-laser device has been
shown to have the potential to quickly identify a cell population that
has begun the rapid protein synthesis and mitosis characteristic of
cancerous cell proliferation. Pathologists currently rely on microscopic
examination of cell morphology using century-old staining methods that
are labor-intensive, time-consuming, and frequently in error.

**Materials Sciences Subprogram**

***Seashell Provides Key to Strong Composites.*** Mollusk shells have
evolved over millions of years to provide hard, strong, tough shelters
for fragile occupants. These outstanding mechanical properties derive
from a laminated construction of alternating layers of biopolymer -- a
biologically produced rubber -- and calcium carbonate, commonly known as
chalk. It has been recognized for decades that materials with
alternating hard and soft layers absorb energy and impede cracking.
Unfortunately, it has proven difficult to transcribe seashell-like
designs into manufacturable materials. Now, a rapid, efficient
self-assembly process has been developed for making "nanocomposite"
materials that mimic the construction of seashells. This process can be
generalized and should lead to materials with unprecedented mechanical
properties.

***Imaging Fluid Distribution and Flow in Materials.*** Dramatic
pictures of the distribution and flow of fluids inside intact objects
and porous solid materials have been obtained by magnetic resonance
imaging (MRI) and nuclear magnetic resonance (NMR). The ability to
observe such images and spectra results from the use of noble gases,
particularly xenon, magnetically polarized by means of a laser. This
advance makes possible the observation of MRI pictures and NMR spectra
in ultralow magnetic fields. The technique produces brilliant pictures
(up to a millionfold increase in brightness) and provides a new
capability for noninvasive investigation of flow and transport. The
images and spectra allow the characterization of atomic distribution and
flow from the smallest scale of nanotubes to the largest scale of
macroscopic samples. The flow of fluids through solid materials is a
crucial component of many industrial processes from the catalytic
conversion of petroleum to the containment of toxic environmental
agents. These advances will eliminate the need for high magnetic fields
in some applications of MRI and NMR, a welcomed event given the cost,
bulk, hazard, and lack of portability of the magnets used in
contemporary instrumentation.

***New Fullerene Species Synthesized - Stickyball, C~36~.*** A new
fullerene species, C~36~, has been synthesized and produced in bulk
quantities for the first time. Fullerenes or \"buckyballs\" are hollow
clusters of carbon atoms. They have been studied extensively since the
Nobel prize-winning discovery of C~60~ in 1985 (supported by BES). C~36~
is the smallest fullerene discovered to date and is characterized by
unusual and potentially very useful properties. For example, in contrast
to C60 molecules, which interact only very weakly with one another,
C~36~ molecules stick together -- hence the nickname \"stickyballs.\"
The lower fullerenes, such as C~36~ are predicted to have more highly
strained carbon bonds, resulting in exciting properties for those
molecules such as very high chemical reactivity and high temperature
superconductivity. The synthesis of C~36~ is particularly significant,
because previously it was believed that any fullerene smaller than C~60~
would be too unstable to isolate in bulk.

***Seeing Clearly Now.*** Using a new imaging technique called
Z-contrast imaging, researchers have achieved the highest resolution
electron microscope image of a crystal structure ever recorded,
resolving adjacent columns of silicon atoms separated by a scant 0.78
angstroms (3 billionths of an inch). Better resolution enables
scientists to see and understand important details they had not been
able to see before. This technique also offers both high spatial
resolution and the ability to distinguish different kinds of atoms. The
precise atomic-scale structure of a material controls the performance of
materials for semiconductor devices, superconductors, and a host of
other applications. Combined with improved electron imaging optics
currently under development, this result promises to revolutionize the
atomic-scale understanding of materials.

***New Family of Bulk Ferromagnetic Metallic Glasses for Energy
Efficient Motors and Transformers.*** New rules for designing alloys
have been developed that enable the creation of a family of bulk
metallic glass alloys. These alloys exhibit outstanding ferromagnetic
behavior with virtually no energy loss. These new alloys are at least 65
percent iron plus contain up to seven other elements. Until now, such
alloys could only be produced as thin foils. Commercial transformers
based on the thin foil ferromagnetic metallic glasses are in service,
but their size and application are limited due to difficulties in thin
foil assembly and manufacturing processes. The new bulk glasses can be
cast into exact shapes and substituted into the standard assembly
processes now in use for traditional crystalline materials. It is
expected that the availability of bulk ferromagnetic glasses will
decrease the energy losses of transformers by about 2/3 compared to
today\'s transformers made from crystalline ferromagnetic materials.
That\'s good news for electric utility customers, since it is estimated
that power-distribution transformer losses cost about \$4 billion
annually.

***Universal Magnetic Behavior in High-Temperature Superconductors.***
Understanding high temperature superconductors remains one of the most
significant research issues in condensed matter physics. The observed
properties of two major classes of high temperature superconductors
initially appeared to be significantly different from one other, leading
scientists to believe that the fundamental interactions responsible for
the superconducting behavior were quite different in the two materials.
However, recent neutron scattering results have shown that the
superconducting behavior of both major classes of superconductors is
connected to excitations of the magnetic spin system in each material.
The new results offer insight on high-temperature superconductivity
including the promise that a single physical mechanism can account for
this phenomenon.

**Chemical Sciences Subprogram**

***Measuring Chemical Processes in Combustion One Molecule at a Time.***
A powerful new experimental instrument just completed at the Combustion
Research Facility promises to provide new information about how
molecules dissociate when given enough internal energy. Understanding
such processes is critically important for combustion, because, at the
high temperatures of combustion, dissociation occurs in a variety of
ways that are difficult to observe, model, and predict. In the
experiment, pulses of laser light a few femtoseconds in duration pump
enough energy into a molecule to cause it to dissociate. (One
femtosecond is one millionth of a billionth of a second.) A second
femtosecond laser pulse ionizes the molecular fragment during the
dissociation process. From the simultaneous measurements of the
fragments produced by the second laser, the details of the dissociation
process can be extracted. These measurements are made one molecule at a
time. This new experimental facility promises to be a tool of unrivaled
power for the validation of predictive models and theories of chemical
reactions.

***New Designs for Molecular Wires Help Mimic Photosynthesis.*** One way
to capture and store the sun's energy is to design systems that mimic
photosynthesis. In nature, biological systems use charge separation to
store energy. This charge separation occurs by transfer of an electron
from a photoexcited donor molecule through a bridge molecule to an
acceptor molecule. Researchers have recently constructed
donor-bridge-acceptor systems in which the bridge -- or molecular wire
-- is a conjugated organic molecule analogous to natural carotenes that
transfer charge over long distances. This research may lead to new
molecular devices for efficient charge separation and storage.

***New Insights into Surface Catalysis.*** One of the oldest problems in
surface-catalyzed reactions is understanding how the molecules actually
come together on a metal surface. Researchers studying the hydrogenation
of acetylene on crystalline nickel using sophisticated atomic and
molecular beam preparations and subsequent thermal desorption
spectroscopy demonstrated that this simple reaction proceeds via
hydrogen absorbed into the bulk of the metal rather than adsorbed on its
surface, as previously thought. This startling discovery has changed the
way we think about industrial hydrogenation catalysts such as Raney
nickel and palladium, and may have general implications for
heterogeneous catalysts presently used in energy-intensive industries
such as ammonia production (the Haber Process).

***First Observation of Relativistic Thomson Scattering -- 60 Years
After its Prediction.*** British physicist J. J. Thomson, who identified
the electron in 1897, showed in 1906 that light could cause electrons to
oscillate up and down and reemit at the same frequency in a dipole
pattern; this phenomenon was subsequently termed Thomson scattering.
Nearly a century later, researchers have demonstrated a new phenomena --
relativistic Thomson scattering -- in which electrons oscillate in a
more complex figure-8 pattern and emit light at both the exciting laser
frequency and multiples of that frequency, each emitted in a different
direction. The more complex pattern results from the electron
interacting simultaneously with both the electric and magnetic fields of
the laser light. To observe this phenomena, the research team built a
tabletop neodymium-glass laser and compressed its billionth-of-a-second
pulses by a factor of about 1,000, boosting their power to 4 trillion
watts of very high-quality beam. This experiment is an important
milestone in the study of nonlinear optics with electrons unbound to
atoms. Furthermore, this work may lead to new laboratory tabletop x-ray
sources producing very short x-ray pulses useful, for example, for
probing molecular motion during reactions.

**Engineering and Geosciences Subprogram**

***Making Waves.*** Unfortunately, many facets of nature exhibit chaotic
changes, driven by external forces, never settling down to a predictable
state. Progress has been made in understanding one kind of chaos in
which information travels from one point to another by means of
traveling waves. Examples include the ripples on a wind-blown lake,
light in a laser, weather patterns, and even the fibrillation of a human
heart. In order to understand this kind of chaos, scientists studied the
flow patterns in a thin layer of fluid heated from below. In certain
fluid mixtures, the patterns move laterally like waves on a pond. The
key discovery is that these patterns can be understood in terms of
so-called phase defects, which are places where the waves circle around
a point in a pinwheel-like motion. Looking at only the defects to
understand the entire pattern is much like keeping track of traffic jams
and accidents to understand the operation of a freeway system. The next
step will be to predict how the patterns change with time. If present
ideas are confirmed, they could be useful controlling such important
phenomena as heart fibrillation, and controlling lasers used in
communications, cutting and welding.

***Changes in Seismic Properties of Rocks Detects Damage.*** Seismology
uses the reflection and transmission of elastic waves to locate
subsurface features of interest. Various types of rocks respond
differently to different kinds and frequencies of waves. The theoretical
geophysics program has developed new techniques to study these
phenomena. The research examines rock behavior through ultrasonic
resonance experiments, which show that rock has both a rapid resonance
response and a slow resonance response. The resonance between the
vibrational modes gives the rock a memory of the shaking it has been
through. The resonance behavior has implications for accurately locating
subsurface features, and for understanding strong ground motion damage
patterns during earthquakes when the resonant modes of regions of
different ground properties couple with those of man-made structures. A
similar resonance response is also characteristic of damaged man-made
materials such as metals, ceramics and composites. Thus the nonlinear
elastic wave studies can contribute to understanding and testing the
characteristics of most man-made materials as well as rock or concrete.

**Energy Biosciences Subprogram**

***Orienting Molecular Syntheses.*** A component of plant cell walls
that severely restricts the use of the carbohydrates in plant biomass is
lignin. Lignins are aromatic polymers that make up a significant
fraction of the earth\'s renewable carbon resources. Research has
provided evidence that the biosynthesis of these large polymers from
smaller lignol units does not proceed in a random fashion, as was
previously thought. Novel plant genes have been discovered that encode
proteins that serve as a scaffold, helping to hold the lignol units in
the right orientation as they are joined together by other biosynthetic
enzymes. These results have broad implications for the efficient use of
plant biomass as well as offering new strategies for enzyme catalysis in
an industrial setting.

***Plant Cell Walls.*** The characteristics of plant cell walls -- the
major energy component of renewable biological resources -- vary to meet
the structural, metabolic, and developmental needs of different plant
cell types. The biosynthesis of the plant cell wall is precisely
regulated to conform to these constraints; however, relatively little is
known about how such variation is achieved during cell wall formation.
Researchers recently identified an enzyme responsible for modifying the
xyloglucan polymer backbone, an important factor in determining cell
wall strength. This discovery offers the potential to isolate similar
enzymes that modify cell wall properties. A better understanding of
plant cell wall biosynthesis can eventually improve the properties of
wood and other biomass materials through the efficient design of
specific complex carbohydrates and other renewable carbon resources.

***Designer Enzymes.*** Research on fatty acid desaturases and
hydroxylases has deciphered the mechanism that controls how these two
types of enzymes introduce a double bond (desaturase) or a hydroxyl
group (hydroxylase) at specific sites along the carbon atom backbone of
long-chain fatty acids. This knowledge of the active site of the two
enzymes has enabled the modification of the gene that encodes the
desaturase for a specific fatty acid to change it into the hydroxylase
and vice versa. Both enzymes perform important tasks in altering the
melting response of the fatty acid to heat. This pioneering work lays
the groundwork for future advances in designing vegetable oils---which
have hundreds of potential uses from heart-healthy margarine to
lubricants and nylon.

**Selected FY 1998 Scientific Highlights/Accomplishments**

**Materials Sciences Subprogram**

***Helping to Solve the Mystery of High-Temperature
Superconductivity.*** Understanding high-temperature superconductivity,
discovered in 1987, remains the outstanding problem in modern condensed
matter physics. Recent neutron scattering experiments suggest that the
electric current in high temperature superconductors may be like
"stripes" of flowing current separated by stripes where current does not
flow. These stripes can be static or dynamic (like the stripes on our
flags, waving in the wind). These and other experiments point to a very
different electron pairing mechanism than that seen in low-temperature
superconductors. Once the pairing mechanism is understood, it will be
easier to find materials with higher critical superconducting
temperatures and better mechanical properties.

***Magnetic Resonance Imaging (MRI) Without Magnets***. Striking, high
resolution MRI images have been obtained without the need for high field
magnets or high frequency detectors normally required for MRI. The
breakthrough involves MRI enhancement by noble gases magnetically
polarized (100,000 fold) through laser treatment. A new ultra-low-field
MRI instrument now makes it possible to obtain extremely bright MRI
pictures of polarized samples in the earth's natural magnetic field,
which is thousands of times weaker than fields obtained from traditional
MRI magnets (which are bulky, expensive, and often hazardous). The new
instrument has been used with localized injection of polarized xenon
solutions into human blood to provide the first observations of the
real-time process of xenon penetrating red blood cells. (Xenon is an
inert gas and an FDA-approved anaesthetic.) This combination of
techniques opens the way to provide high resolution MRI images of
localized areas in animal and human subjects.

***Discovery of New Materials Using LEGO.*** Of the enormous number of
combinations of elements in the periodic table, only a very small
fraction are used in real materials. It is quite certain that materials
with optimum properties for various applications have not yet been
discovered. For example, high-temperature superconductivity occurs in
ceramic compounds with a most unlikely combination of elements. A new
strategy using fast computers and concepts from quantum mechanics has
been developed to search for \"winning combinations\" of atoms to
produce materials with improved physical properties. This approach \--
Linear Expansion in Geometric Objects (LEGO) \-- recognizes that even
complex crystal structures can be viewed as a collection of simple
geometric objects such as dumbbells, triangles, etc. By assigning each
geometric object an energy value, computers can rapidly scan hundreds of
thousands of candidates looking for the lowest overall energy and,
therefore, the most stable structures. LEGO has already predicted
several new intermetallic compounds missed through conventional
approaches.

***Electrically Conducting Nanoscale Ropes.*** Incredibly light
synthetic metals with a potential electrical conductivity 50-100 times
better than copper per weight are being made from carbon nanotubes doped
with metals. First discovered in 1991, nanotubes are a new class of
materials formed from graphite-like sheets of carbon rolled into
exquisitely small cylinders. They self organize in the vapor phase
during growth to form well ordered crystalline bundles of individual
nanotubes. The introduction of dopant atoms, such as potassium or
lithium, into the open spaces between adjacent tubes within a rope can
increase electrical conductivity significantly at room temperature.
Doped nanotube ropes are also attracting increased interest as
constituents of novel nanoscale device structures and as replacements
for pure lithium metal in Li ion batteries.

***Molecular Bricks for Nanotechnology.*** Lightweight materials are
commonly composed of polymers, which are long chains of atoms. The
chains are difficult to order completely, which limits their
functionality and durability. Researchers have recently demonstrated new
possibilities for the design of polymers using nano-objects, which can
be regarded as molecular bricks. These bricks, which might have shapes
as diverse as those of nature\'s proteins, create a toolbox for the
design of lightweight materials that could self assemble into structures
with surprising functionality. Using the first elements of this toolbox,
a spherical nanostructure has been created that has internally
continuous channels; some channels transport water and ions, while
others block water but accept organic substances. These nano-sponges
could trap toxic metals from water streams.

***What Makes Stainless Steel Stainless?*** Corrosion damage is
estimated to cost the U.S. 4.2 percent of the Gross National Product
each year. Metals can be used in industrial and technological
applications only when appropriately protected. In the case of stainless
steel and many other metals, protection is provided by a thin oxide film
that prevents further corrosion. However, the structure of these oxide
films has remained a mystery despite decades of study. Recent research
using surface-sensitive synchrotron x-ray diffraction with a combination
of electrochemical experiments has now unambiguously determined that the
oxide film on pure iron has a very fine-grained, nanocrystalline
structure. Results for iron-chromium alloys (e.g., stainless steel) have
shown that the oxide films are also nanocrystalline. This overturns the
long accepted belief that stainless steel is corrosion resistant because
its oxide film is non-crystalline. These surprising results provide a
more realistic basis for understanding corrosion resistance and for the
development of better corrosion protection coatings.

***Do Cracks \"Melt\" Their Way through Solids?*** Predicting and
explaining why, how, and when solids fracture is a significant
scientific challenge. The driving force for fracture is intensification
of the local stress at a crack tip, yet the mechanism by which local
strain is dissipated during crack propagation is not well understood.
Can strain energy be dissipated via "local melting" around the crack
tip? Recent computer simulations of crack formation predict this
intriguing possibility. Simulations indicated that the melting in front
of a crack tip can lead to catastrophic fracture. Using high-voltage
electron microscopy, observations of moving crack tips in an
intermetallic compound confirmed the prediction of the computer
simulations and showed the development of melted and rapidly
re-solidified regions adjacent to the crack tip. This new picture of
fracture as a stress-induced melting process may lead to new approaches
to stress-corrosion cracking in the automotive, aerospace, power
generation, and ship building industries.

***Smart Filters.*** New materials with tailored pore sizes and pore
chemistry can selectively remove deadly heavy metals \-- such as
mercury, lead, and silver \-- from water. Researchers discovered that
precise control over the amount of water in the pores of porous silica
enabled the insertion of useful organic molecules on the walls of the
pores. Using this knowledge, monolayers of organic sulfur compounds were
bound to the internal surfaces of porous silica to prepare selective
filter materials. The high surface area of the porous silica (a few
grams have as much surface area as a football field) coupled with the
bonding characteristics of the organic compounds results in high
filtering capacity and high selectivity for specific contaminants. In
addition, pore openings in the silica are designed to be too small for
microbes to enter and digest the contaminants, later causing human
illness from, for example, mercury contamination. The filter materials
can purify highly contaminated water in a single treatment to a level
that exceeds drinking water standards. The filters can also be recovered
and reused after removing the contaminants.

***A Line in the Sand.*** Granular materials like gravel, salt, or dry
chemicals are ubiquitous in our daily lives and central to many
industrial processes, yet controlling their motion is both surprisingly
difficult and not well understood. For example, granular material
subjected to a driving force remains at rest until a minimum \"critical
force\" is applied; then it moves in uncontrollable events like
avalanches. Inefficiency in handling granular materials may result in
the loss of up to 40 percent of the design capacity of industrial
plants. In its retrospective of the last 50 years, Physics Today
highlighted the emerging science of granular materials as a notable
event of the last decade. Scientists have recently developed a
theoretical approach to describe the motion of granular materials in a
vibrating environment. This theory correctly describes the unexpected
formation of stripe, square, and hexagon patterns on the surface of
vibrated granular media and the formation of localized excitations
called \"oscillons.\" The theory also predicted how to control aspects
of granular motion \-- a prediction that was confirmed by experiment.
The new theory brings the description and control of granular motion to
a higher level of understanding and shows promise of substantial
advances in basic granular science, which can lead to industrial
applications that exploit the controlled motion of granular materials.

***Vortex Matter \-- A New Understanding of Magnetism in
Superconductors.*** Magnetic fields in superconductors are carried by
\"vortices.\" Each vortex consists of a tube of magnetic field
surrounded by a circulating flow of electrons that move without
resistance. It is this free flow of electrons that gives superconducting
materials their special property. Recently, it has been shown that the
system of magnetic vortices can take many forms analogous to the solid,
liquid, and gaseous forms of ordinary matter. The analogy between the
behavior of vortices and ordinary matter is so strong that a new term
has entered the scientific vocabulary \-- vortex matter. Vortex matter
melts from a crystalline to a liquid state in much the same way that ice
melts to water. The properties of vortex matter can be controlled over a
wide range. For example, the density of vortices can be varied by a
factor of 10,000 simply by changing the applied magnetic field. This
remarkable control enables the study of many types of phenomena in
vortex matter whose analogies in ordinary matter are difficult or
impossible to observe. Thus, the identification and characterization of
the melting transition in vortex matter has significant implications for
phase transitions in ordinary matter, for understanding the
electromagnetic properties of superconductors, and for developing
applications of superconductivity.

# Chemical Sciences Subprogram

***Landmark Experiment Challenges Combustion Models***. Combustion is
perhaps the oldest technology in human experience, yet its complexity
limits predictions of combustion processes in devices ranging from
simple laboratory burners to automobile engines. The challenge is
characterizing the influence of chemistry and fluid dynamics on one
another. A simple experiment recently has demonstrated a major error in
current models for combustion processes. The experiment allows the
interaction of chemistry and turbulence to be examined in quantitative
detail for the first time. A planar flame sheet is deformed by a puff of
air generated by a small loudspeaker. Spectroscopic techniques are used
to determine the concentrations of reaction intermediates as the flame
sheet deforms. Comparisons of these experiments with computational
simulations showed that the widely accepted chemical reaction mechanism
for simple methane combustion is in error, thus, requiring a fundamental
change in our models for combustion.

***Fishing for Radioactive Actinides with Molecular Hooks.*** The
selection, separation, and removal of radioactive actinide ions from
complex aqueous waste stream mixtures remain vexing technical issues.
The development of new, improved separation approaches will result in
significant cost savings for nuclear waste treatments as well as improve
environmental safety and materials safeguard security. A new family of
chelate agents or \"chemical fish hooks\" suitable for the reversible
\"catch and release\" of trivalent actinide ions in highly acidic
solutions has been designed, prepared, and characterized. The latest
chelate derivatives show separation characteristics that are especially
suited to practical, batch type waste treatments.

***First Isolation of a Catalytic Oxidation Intermediate.*** Despite
worldwide efforts over the last 15 years on catalytic olefin oxidation,
little progress has been made in extrapolating from ethylene (the
smallest olefin) to larger olefins such as propylene. The key question
\-- the molecular mechanism of ethylene epoxidation (which gives us
anti-freeze and polyester fibers) \-- remains unresolved. Now, a
combined experimental and theoretical tour de force has yielded the
first definitive isolation and spectroscopic characterization of a
stable intermediate in the catalytic process \-- an oxametallacycle.
Calculations were employed to determine the structure for the
oxametallacycle on silver and to predict the infrared spectrum and
molecular motions for that structure. Conclusive identification was
provided by the excellent agreement between the predicted infrared
spectrum and the experimental electron energy loss spectrum.

***Liquid Crystalline Organic Semiconductors Discovered***. Liquid
crystals change their optical properties as they transition between
distinctive geometric states. Digital watch displays, for example, cycle
between transparent and opaque forms. They, like other technologically
important liquid crystals, are electrically insulating. Semiconducting
crystals could have much broader application than insulating crystals,
but large single crystals of these materials are difficult and expensive
to produce. In a recent breakthrough, a family of liquid crystalline
derivatives of perylene diimide was discovered that has semiconductor
properties. The films of one compound self organize from a red,
polycrystalline phase with randomly oriented crystallites into a black
phase with highly ordered ribbon-like structure. The fluorescence
intensity increases seven-fold during the transformation. This
spontaneous change in photophysical properties makes this class of
organic liquid crystals look very promising for future photoconversion
applications.

***Diode Lasers Detect Radiotoxic Isotopes.*** Solid-state diode lasers,
similar to those used in compact disc players, have been used in a new
approach to detect the toxic radioisotope strontium-90, which received
attention because of high levels found in milk after atomic weapons
tests and the Chernobyl reactor accident. Diode lasers excite and
efficiently ionize the strontium atoms; the resulting ions are detected
using a mass spectrometer. The high efficiency allows the detection of
less than one femtogram (femto = 10-15, e.g., a single postage stamp
compared to the area of Texas) of strontium 90. Furthermore, it is
possible to selectively ionize the strontium 90 even in the presence of
large excesses of the stable, naturally-occurring isotopes of strontium.
Measurements can be performed in a few minutes as compared to the
several weeks required previously for conventional radiochemical decay
counting methods. Thus, this new approach should significantly improve
the capabilities for near real-time monitoring of environmental
restoration activities, nuclear weapons tests, reactor accidents, and
the processing of nuclear fuels.

***Photochemical Studies on the Light-Activated Drug Hypericin.*** The
popular herbal remedy St. John\'s wort contains the compound hypericin,
which upon exposure to light is toxic to tumors and HIV, the human AIDS
virus. Now, the fundamental photochemistry of hypericin has been
elucidated. A novel laser spectroscopic technique, fluorescence
upconversion, was used to show definitively that the primary
photochemical process is excited-state intramolecular proton or hydrogen
transfer. Any incomplete proton or hydrogen atom transfers would acidfy
the aqueous solution immediately surrounding hypericin, which may be of
importance in its toxicity to viruses. The study is yet another example
of the role that the physical sciences play in providing fundamental
information relevant to a wide variety of subject areas.

# Engineering and Geosciences Subprogram

***Remote Sensing of Fractures and Prediction of Failure in Rocks***.
Long before catastrophic fracturing and failure of a material, sound
waves transmitted through the material show a dramatic frequency shift.
This shift has been documented before in fractured materials, but the
observation of the shift before the formation of a continuous crack is a
new discovery. Monitoring for the frequency shift can therefore be used
to provide a warning of failure. The sound shifts to a lower frequency
because the high-frequency sound (with shorter wavelengths) is
preferentially absorbed or scattered. Because the frequency shift occurs
prior to creation of a single fracture, there should be a network of
oriented, disconnected features appearing prior to a crack that absorb
or scatter the high-frequency sound in the same way as do observable
cracks. Connected cracks in rocks provide pathways for water, oil, or
pollutant flow. The growth of cracks can improve fluid flow or cause
failure of well-bores, reservoirs, and tunnels or engineered structures;
therefore, it is very important to understand how and when cracks form.

# Energy Biosciences Subprogram

***Building Doors into Cells.*** Before any molecule can enter a cell,
it must first pass through the cell membrane---the thin, fat-containing
film that covers all cells. The passage of most molecules through
biological membranes is controlled by pores, defined openings made with
specific proteins. The composition and structure of pore proteins can
now be altered through genetic engineering. Changes in the size of the
pore, the selectivity of the pore for letting different molecules pass
through, and the pore\'s ability to open and close are three properties
currently being studied by bioengineering new pore proteins. Successful
attempts to engineer modified pore opening and closing properties have
provided insight on how these processes can occur mechanistically as
well as for developing new biotechnological applications. Among the
potential products of this research are chemical triggers or molecular
switches that can be used to create new sensors to detect harmful
chemicals or viruses. Other potential applications are the development
of small light switches and new drug delivery systems.

## Selected FY 1997 Scientific Highlights/Accomplishments

***The Advanced Photon Source (APS) Completes Its First Year of
Operation.*** As the floor of the APS became crowded with experimental
hutches, new results emerged that took advantage of the very high
brightness of this new light source and that could not have been done
elsewhere. While much of the work at the APS and the other BES
synchrotron radiation light sources has been and will continue to be in
the area of materials sciences and condensed matter physics, many
studies are also being done in the areas of biological, plant,
environmental, and geosciences. For example,

\- A new structural determination and biochemical analysis of the human
fragile histidine triad (FHIT) protein has been performed. The FHIT
protein derives from a fragile site on human chromosome 3 that is
commonly disrupted in association with cancers. The understanding of
this tumor suppressor protein will focus on a diverse human HIT family
member in search of their in vivo function throughout biology.

\- The first experiments were conducted with a newly constructed
beamline for geosciences/soil/environmental research. Molecular-scale
observations (made possible by the high brightness of the APS) enable
new understanding of local structural and chemical changes that govern
the mechanisms of mineral-fluid interactions. For example, the molecular
form or speciation of environmental contaminants, such as chromium,
arsenic, lead, uranium or plutonium, determines their toxicity and
bioavailability.

\- Over 90% of the world\'s plants, including essentially all crops,
make use of symbiotic associations with fungi. X-ray imaging studies
performed on these systems using an x-ray microprobe have provided
detailed information on the elemental distribution in plant roots and
associated fungi. These images, with unprecedented spatial resolution,
will be a key to understanding the symbiosis between the plant roots and
fungi.

**Materials Sciences Subprogram**

***Breakthrough in Processing of Aerogel Films.*** A breakthrough in the
processing of ceramic aerogel films won a prestigious award of the
American Chemical Society and was cited as an important discovery by the
Wall Street Journal. This breakthrough overcame the sixty year barrier
to the large scale commercial utilization of these films. Aerogel films
have a foam-like structure, exceptional lightness and transparency, and
are ideal insulating materials for double-paned windows and other uses.
When freshly formed from a liquid, the film can be easy torn until it
has been hardened. Older processes required a toxic liquid and high
pressure and temperature to dry the films. Employing a new understanding
of film drying and chemical treatment of the surfaces of the pores in
the film, a non-toxic, low-pressure and temperature process was
developed to keep the film flexible and resilient as it formed.

***Cool Sounds.*** Air conditioning from your favorite music? Not quite
yet. However, sound, or acoustic energy, has now been used to make
refrigerating and heating units. These devices, called thermoacoustic
refrigerators, or thermoacoustic engines when operated in a heating
mode, have no moving parts and use sound waves in air or helium to
transfer heat. Operation of these devices has been based upon a standing
acoustic wave in a closed system, limiting their usage. Now, a radically
new concept has been devised in which the air or helium would flow
slowly through the device during operation. This concept would allow for
heating and cooling of buildings and for other industrial air
conditioning applications with an economic advantage over current
technology through the elimination of the bulky heat exchangers on
building roofs. First results from a test system operating as a
refrigerator using helium or air have confirmed the concept. Further
developments of this concept are under way.

***Slick and Sticky.*** Pencil-shaped organic molecules called
\"rod-coils,\" designed and synthesized to have half of the molecule
rigid and the other half flexible, were discovered to exhibit unusual
and important clustering mechanisms on several size scales. Aggregates
of these molecules self-assemble into mushroom-shaped clusters with the
rigid ends forming the stems and the flexible coils forming the caps. At
the next level of organization, the mushroom clusters pack side by side
into layered sheets to form, ultimately, a thick film. Because the
building-block molecules are all oriented in the same direction, the
film\'s properties mirror those of the individual molecules, resulting
in a film whose bottom surface is sticky and top surface is slippery.
Such a film has many potential applications, for example as an anti-ice
coating on an airplane wing or an anti-blood-clot lining for artificial
blood vessels. This new molecular organizational technique is being
explored to make films with other properties by replacing the slippery
and sticky groups capping the rodcoils with compounds that perform other
functions, such as conducting electricity or changing their size in
response to an electrical pulse.

***Materials Failure in a Radiation Environment.*** The safe storage of
nuclear materials and radioactive wastes is a major challenge for the
post cold-war generation. The long term effects of radiation on the
physical integrity of these materials and their containers is still
poorly understood. Recent work using simultaneous electron microscopy
and ion irradiation experiments shows that the impact of just a single
high energy ion on the surface of a material has a much greater effect
than previously realized and disrupts tens of thousands of atoms near
the surface of the material. The impact causes local melting,
displacement of many atoms beneath the surface, and the formation of
surface craters and holes. This work should lead to a correct
understanding of how materials are damaged by radiation and will help
explain and predict the behavior of materials used for waste storage and
other applications.

***Powder Process Produces Cheaper Stronger Permanent Magnets.*** A
collaborative team from two laboratories is a recipient of a prestigious
R&D 100 Award for the processing of nanocrystalline composite powder for
high-strength, permanent magnets. The permanent magnet industry is a
very large global industry worth 3.2 billion dollars in 1995 and is
predicted to reach 10 billion dollars by 2010. The high magnetic
strength of the prize-winning neodymium-iron-boron \'super magnets\'
results from matching the crystallite size formed on cooling the alloy
from the melt to the size of the magnetic domains. The previously used
rapid cooling process that creates the fine-grained polycrystalline
material is too expensive for many commercial magnet applications. It
was discovered that adding titanium and carbon to the molten alloy
allows a spray atomization process to create appropriately sized
particles that can be consolidated into magnetic compacts.

***New Process Forms Diamond-Like Boron Nitride Films.*** A process to
grow diamond-like boron nitride films, the second hardest material
known, has been discovered based on a new understanding of how hard
nitride films are formed. Like diamond, films of boron nitride can be
grown from hot gases and plasmas without the use of high pressures.
However, it was recently discovered that irradiation of boron nitride
films with low-energy ion beams will produce films of boron nitride that
contain the hard, diamond-like form rather than the soft graphite-like
form. This new process to form ultra-hard boron nitride films could
revolutionize the tool industry, because, unlike diamond, boron nitride
does not react with iron or steel; therefore, boron nitride is an ideal
material for cutting tools.

***A Microscopic Understanding of Materials Joining Enables the
Intelligent Processing of Materials.*** Welding is a critical
fabrication technology used extensively in a wide variety of industries
such as energy, automotive, construction, aerospace, shipbuilding, and
electronics. Weld failures are among the most common reason for
unscheduled outages in power plants with the cost of replacement power
often exceeding \$1,000,000 per day. Recent advances in materials
joining science have improved our understanding of the welding process
and welded materials. With the help of massively parallel computers,
complex physical models that link both macro- and microscopic scale
phenomena during the melting and solidification of a weld have been
developed. Using such models it is now possible to visualize directly
the solidified weld microstructure for a given set of processing
conditions. The resulting knowledge has been transferred to industry
thereby allowing the intelligent processing of defect-free, structurally
sound and reliable welds.

***Magnetic Refrigeration to Eliminate Harmful Freon.*** Conventional
air conditioning of domestic and commercial buildings, and cooling in
food processing and other industrial plants requires enormous quantities
of electricity and uses huge amounts of environmentally harmful
chlorofluorocarbons (CFCs). Magnetic refrigeration uses the
magneto-caloric effect, the ability of a magnetic material to raise its
temperature upon application of a magnetic field and to lower it upon
removal of that field. For many years the alloys showing this effect
operated only at impracticably low temperatures. New understanding of
thermal and magnetic behavior uncovered a gadolinium-silicon-germanium
alloy that cools efficiently near room temperature. Refrigerator devices
based on magneto-caloric material could cut energy costs and eliminate
ozone-depleting CFCs.

**Chemical Sciences Subprogram**

***\"Green\" Separation Process for Hanford Wastes.*** The radioactive
components in the Hanford waste tanks comprise a mere 1/100th of a
percent of the millions of gallons of contaminated waste in storage.
Thus, highly selective removal of the radioactive components could
significantly reduce the volume of waste, which will require very costly
processing and long-term storage. Fundamental studies of technetium
extraction in the 1980s, followed by more recent investigations of the
structural and thermodynamic aspects of the extraction of alkali metal
salts with crown ethers has led to a new technetium extraction process.
The crown ether binds sodium ions already present in the waste, and then
extracts technetium as much as four orders of magnitude better than
others ions in the waste, such as nitrate, which are present at much
higher concentrations. The crown ether complex is readily decomposed by
contact with water to release the extracted technetium thereby affording
a convenient, safe, and economical stripping method. The crown ether is
then recycled thus minimizing secondary waste production.

***New Metallocene Catalysts Lead to Commercial Applications.*** The new
family of metallocene polymerization catalysts, in which polymerization
occurs principally at a single type of metal center with a well-defined
coordination environment, are a substantial advance over the prior
heterogeneous polymerization catalysts. Recent advances on two fronts
\-- strained early transition metals and non-coordinating counterions
\-- have resulted in new commercial applications by Dow Chemical and by
Exxon Chemical. The remarkable stereospecificity features of these new
catalysts have not only led to a variety of new, advanced polymer
products over a wide range of densities, but they also provide the
ability to \"turn a microscope on\" the underlying molecular mechanisms,
thus leading to continually improved catalysts and products. The new
polymers produced from these catalysts are found in wide-ranging
applications from food wrapping to the plastic front end front bumper
combinations on automobiles. The impact of these new products can be
imagined from the Dow Insite process, which produces plastics with a
market of about \$2,000,000,000 per year at Dow\'s Texas plant.

***Joint Program Results in a New \"Smart\" Window.*** Windows with
reduced transmission have been shown to be energy savers by reflecting
some of the heat from solar radiation. However, such windows have fixed
transmission that also reduces visible light. On a cloudy day a building
or home equipped with such windows may not have adequate natural
lighting. Research jointly supported by BES and the Department\'s Energy
Efficiency program has led to the initial development of a self-powered
\"smart\" window that can control its own transparency. Integration of
two technologies, electrochromic windows and dye-sensitized solar cells,
yields a smart window that darkens, reversibly, when exposed to
sunlight.

**Engineering and Geosciences Subprogram**

***Fast-Transport Predicted in Subsurface Fluids.*** Underground flow
properties of fluids containing two or more components (oil(s)/water)
are a major issue for environmental remediation. New experimental work
documents how upward and downward flow of different fluids can be driven
by differences in their density and their tendency to diffuse. Such
transport occurs much more rapidly than has been predicted by earlier
models. This new research developed innovative experimental methods to
test the earlier predictions, and successfully measured and modeled the
effects of multiphase flow in simple porous materials. This work is a
significant step towards developing improved models to make better
predictions for complex and highly variable natural subsurface
environments.

**Energy Biosciences Subprogram**

***New Sensor Provides Instant Litmus Test for Pathogens.*** A new class
of colorimetric sensor materials has been invented that makes it
possible to instantaneously and inexpensively detect a wide range of
biological toxins and common disease-causing organisms. Building on
earlier discoveries, researchers have developed a thin film consisting
of receptor molecules attached to a film of linked diacetylene
molecules. The film transmits blue light. The surface receptor molecules
are designed to very selectively bind specific pathogens causing the
film molecules to reorganize and the film to turn red. Pathogens thus
far detected with good sensitivity include an influenza virus, cholera
toxin, botulism toxin, and the toxin produced by the bacteria
responsible for 200 deaths per year in the US alone, as noted by the
recent contamination of fruit drinks and fast food hamburgers. Existing
tests for all of these pathogens require at least a 24 hour culture.
After further development, the sensors can be placed on plastic, paper,
or glass and incorporated into inexpensive packaging and portable
detection devices.

***Silicon in Biology.*** Silicon is an element that is a principal
component of glass, computer chips, coatings and numerous consumer
products. There are only a few biological systems that metabolize this
element. Silicon is metabolized by some simple animals, by algae to make
the equivalent of glass houses, and by some higher plants (the rough
feel of corn leaves comes from shards of silicates in the leaves).
Recently a gene was identified that encodes a protein that is involved
in binding and transporting silicon into a cell. This discovery will
extend our understanding of how silicon is taken up and processed by
biological systems which may lead to applications such as the mining of
silicon from seawater and the manufacture of silicon-containing
products.

***Bioproduction of Natural Gas.*** The few microorganisms that possess
the ability to produce methane (natural gas) have been studied for a
number of years in the hope of using these organisms to produce a
renewable energy source. Last year the genome of a methane-producing
bacterium was sequenced which showed the uniqueness of these organisms.
It is now thought that these bacteria are among the first life forms
ever developed on earth. Recently, procedures have been developed which
will permit the genes of methane-producing bacteria to be manipulated.
This development will allow scientists to determine the nature and
properties of these organisms and their unusual metabolism.

***Controlling Natural Energy Resources through Plant Genetic
Engineering.*** Cellulose is the most prevalent biological compound on
earth. It is the principal component of all plants, wood, paper and
cotton. When considered globally, cellulose constitutes an enormous
supply of chemical energy, all of it renewable. Recently, several plants
have been manipulated to make significantly less cellulose. This
modification is important because it may now permit identification of
the factors that control the synthesis and deposition of cellulose and
related compounds. This development may permit the genetic engineering
of plants to produce either more cellulose, or plants that produce
larger amounts of other chemicals such as liquid fuels and plastics.

[^1]: BES defines \"users\" as researchers who conduct experiments at a
    facility (e.g., received a badge) or receive primary services from a
    facility. An individual is counted as one user per year regardless
    of how often he or she uses a given facility in a year. "Operating
    hours" are the total number of hours the facility delivers beam time
    to its users during the Fiscal Year. Facility operating hours are
    the total number of hours in the year (e.g., 365 days times 24
    hour/day = 8,760 hours) minus time for machine research, operator
    training, accelerator physics, and shutdowns (due to maintenance,
    lack of budget, faults, safety issues, holidays, etc.).