Seeing soft tissues with X-rays

Scientists at DOE's Brookhaven National Laboratory are helping to develop a novel x-ray imaging technology capable of "seeing" soft tissues invisible to conventional x-rays. Conventional radiography produces images based on how x-rays are absorbed by tissue. The new technique, called Diffraction Enhanced Imaging (DEI), looks at how intense x-rays from a synchrotron such as the National Synchrotron Light Source bend and scatter as they pass through the tissue. Diffraction and scattering angles vary more subtly between tissue types, making soft tissues such as skin, fat, and blood vessels—as well as bone and other hard tissues—visible with just one technique.

[Karen McNulty Walsh, 631/344-8350;
kmcnulty@bnl.gov]

Quantum investigations

DOE's Ames Laboratory physicist Viatcheslav Dobrovitski and his collaborators have been using supercomputers to simulate the behavior of quantum states subject to interactions with an environment. This is a topic of crucial importance for the successful operation of so-called quantum computers, where the integrity of quantum states can be destroyed (decohered) by interaction with surrounding nuclear spins, lattice vibrations and other "environmental perturbations." Dobrovitski's work shows that in certain instances there can be a large degree of decoherence in the system, yet some of the quantum mechanical memory is maintained, with quantum oscillations lasting well beyond an initial decoherence period.

[Saren Johnston, 515/294-3474;
sarenj@ameslab.gov]

Precise measurements give clues to astronomical X-ray bursts

[Dave Jacque, 630/252-5582;
info@anl.gov]

Fermilab aids data management for sky surveys

Richard G. Kron

Richard G. Kron, professor of astronomy and astrophysics at the University of Chicago and scientist at Department of Energy's Fermilab, is the new director of the Sloan Digital Sky Survey—a collaboration of 13 institutions around the world and 200 astronomers. By 2005, the SDSS collaboration will complete the digital imaging and spectroscopic survey of one quarter of the entire sky, determining the positions and absolute brightnesses of more than 100 million celestial objects. In May an SDSS study provided the most direct evidence yet that galaxies reside at the center of giant, dark matter concentrations that may be 50 times larger than the visible galaxy itself. All SDSS data is stored at and distributed by Fermilab.

[Sena Desai, 630/840-2237;
sena@fnal.gov]

New understanding of sea salt to help climate modeling

While a breeze over the ocean may cool beach goers in the summertime, a new scientific study has revealed that tiny wind-blown sea salt particles drifting into the atmosphere participate in a chemical reaction that may have impacts on climate and acid rain. The research by scientists at DOE's Pacific Northwest National Laboratory and the University of California Irvine could have substantial implications for increasing the accuracy of climate models. The study indicates that sea salt plays an important role—but one previously not well understood—in the chemistry of sulfur in the atmosphere. One form of sulfur—sulfur dioxide—is formed when naturally emitted sulfur-containing compounds react in the atmosphere. In the air, sulfur dioxide is converted to sulfuric acid, a major component of acid rain and a contributor to haze in the atmosphere. These haze particles can affect clouds, which play an important role in climate.

[Staci Maloof, 509/372-6313;
staci.maloof@pnl.gov]

Stopping uranium cold

If researchers can duplicate in the field what they have done in the lab, uranium that contaminates soil and water could be immobilized at a fraction of the cost of other methods of decontamination. The goal of researchers at DOE's Oak Ridge National Laboratory and Stanford University was first to identify what kind of bacteria, or bugs, inhabit the water and soil of a Y-12 National Security Complex site contaminated with uranium. Next, they determined which bacteria could immobilize iron and uranium by forming insoluble complexes. By increasing the activity of the bacteria with this desired trait, researchers hope to dramatically reduce the chances of uranium-contaminated water leaving the site. Researchers expect this approach to have applications at many sites that are contaminated with uranium, chromium or technetium.

[Ron Walli, 865-576-0226;
wallira@ornl.gov]

Sauthoff heads ITER planning
for U.S

Ned Sauthoff

Possessing a special blend of scientific and managerial accomplishments makes Ned Sauthoff, a researcher at the DOE Princeton Plasma Physics Laboratory (PPPL), uniquely qualified to serve as the U.S. ITER Planning Officer. He was appointed in February.

"Dr. Sauthoff heads PPPL's Offsite Research Department, which supports the Laboratory's successful collaborations on fusion research facilities in the U.S. and abroad. This has given him a deep understanding and appreciation of both the U.S. and the international fusion research teams. Ned has brought to this activity a rare combination of abilities in the areas of research, planning, and management. His achievements and special qualities will serve him well in his new responsibilities on ITER," said PPPL Director Rob Goldston.

ITER - Latin for "the way" - is a major international magnetic fusion research project with a mission to demonstrate the scientific and technological feasibility of nuclear fusion as an inexhaustible, safe, and environmentally attractive source of energy. ITER could begin construction in 2006 and be operational in 2014, with fusion research lasting up to 20 years. The parties include Canada, China, the European Union, Japan, Korea, the Russian Federation, and the U.S.

As U.S. ITER Planning Officer, Sauthoff is assisting in negotiations for ITER management, and procurement allocations and systems, as well as in determining possible U.S. contributions to the project. His first task is to help form a multi-institutional working team of people from around the U.S. fusion program to assist in the ITER effort.

"The team will be structured in a way that invites participation by the full U.S. fusion community," said Sauthoff, adding that he hopes all U.S. fusion researchers will be involved in the international project. "Fusion physicists and engineers should see ITER as an opportunity to pursue the study of burning plasmas and to advance fusion technology." A plasma is a hot ionized gas which serves as the fuel in which fusion occurs.

Presently, the desired roles for U.S. ITER involvement are being formulated. "During negotiations with the other international partners, we want to assure that the U.S. fusion community can pursue its interests on ITER," the U.S. ITER Planning Officer said.

Sauthoff came to PPPL in 1972. He received a bachelor's degree in physics from the Massachusetts Institute of Technology (MIT) in 1971, a master's in nuclear engineering from MIT in 1972, and a Ph.D. in Astrophysical Sciences from Princeton University in 1975. He is a former president of the Institute of Electrical and Electronic Engineers-USA.

Submitted by DOE's Princeton Plasma Physics Laboratory