| February 20, 2006
Proton radiation more dangerous than once thought
At the NASA Space Radiation Laboratory at DOE's Brookhaven National Laboratory, scientists have found that proton radiation is more damaging to cells than previously assumed—specifically, the cells' DNA. Since protons are the most abundant type of particle in deep space, this research may help scientists design spacecraft and spacesuits that can properly protect astronauts traveling far from Earth. Additionally, this work sheds light on the true nature of proton radiation, which was thought to damage tissue in a way similar to x-rays. The results of the study show, instead, that protons are as damaging to DNA as high-energy iron ions and other heavy charged particles.
[Karen McNulty Walsh, 631/344-8350,
Editor's note: Feb. 20's e-mail alert incorrectly identified this Brookhaven Lab item as from Berkeley Lab.
Gold 'shines' differently at the nanoscale
Researchers at DOE's Argonne National Laboratory have found that gold "shines" in a different way at the nanoscale, and the insights may lead to new optical chips for computers or for switches and routers in fiber networks. The Argonne researchers examined the characteristics of photoluminescence in gold nanorods, and found that they could control the wavelength of the light emitted by the material, making it possible to use as a light source inside an optical chip, allowing transmission of information through light. The gold nanorods are about 20 nanometers wide and range from 70 to 300 nanometers long.
[Catherine Foster, 630/252-5580,
Boson or boson lite? DZero event sets limit on Higgs boson mass
How do particles get their masses? Physicists study the Higgs field, and hence, a particle associated with this field called the Higgs boson, to answer that question. Although no direct evidence for the Higgs boson has been found, researchers at the DZero experiment at the DOE's Fermilab are searching for the Higgs boson using several production channels. Results from a recent search for simultaneous production of a Higgs boson and a Z boson suggest that the Higgs mass range should be between 100 to 140 GeV/c 2, a region where the Tevatron has the capability of producing it. This limit is consistent with the Standard Model.
[Dawn Stanton, 630/840-2237,
Making a good thing even better
When Ames Laboratory senior metallurgist Iver Anderson patented a tin-silver-copper solder back in 1996, it was a major break-through in the search for a lead-free substitute for traditional solder. With the European Union banning lead and other hazardous materials from all appliances July 1, Ames Lab's lead-free solder has been licensed by more than 60 companies world-wide. But Anderson 's group is continuing to work to address the problem of brittleness as the solder "ages" at high temperature. By adding zinc to the tin-silver-copper mix, Anderson 's initial findings show that solder joints made with the zinc-modified solder withstand much higher impacts than those made with the regular lead-free formula.
[Kerry Gibson, 515/294-1405,
PPPL's Monticello focuses
on the 'fourth state'
Whether his gaze is tilted toward the heavens or at a computer screen, the focus has always been plasma for Don Monticello, a scientist at the DOE Princeton Plasma Physics Laboratory (PPPL). Plasma is the fourth state of matter—a hot, gaseous, electrically charged state that makes up the sun and the stars, and is used as the fuel to produce fusion energy. At PPPL, physicists use a magnetic field to confine plasma.
Monticello is a theoretical physicist whose research leads to advances in understanding the behavior of plasma and how fusion devices operate. At PPPL, his pioneering work focuses on modeling plasma disruptions and three-dimensional computational simulations of laboratory plasmas. Presently, his primary responsibility is calculating equilibria—various modes of stable plasma performance—for the National Compact Stellarator Experiment (NCSX), an experimental fusion device being constructed at PPPL. He is part of a team that has developed a computer code capable of calculating the shape a three-dimensional plasma would take in fusion devices called stellarators. This was a key tool in the design of NCSX.
He joined the Laboratory's Theory Group in 1975 after receiving a bachelor's degree and a Ph.D. in physics from the University of Rochester and spending two years at the Institute for Advanced Study in Princeton, N.J. At the Institute, Monticello and coworkers involved in computational science were among the first to do large-scale computations involving the motion of electromagnetic waves along the magnetic field lines in a plasma. At PPPL, he continued this work, developing a set of reduced equations that allowed one to simulate the evolution of the plasma in fusion devices on computers, which previously had not been feasible.
"Understanding the behavior of the plasma in fusion devices is essential in the successful design and operation of fusion devices," says Monticello, whose work has significantly contributed to this understanding.
The father of five and grandfather of six, who devotes his outside time to family, fitness, sports, and astronomy, freely shares his enthusiasm for fusion and plasma science research—as well as astronomy—with the public through talks for various groups. "It is really rewarding to work in fusion because the potential benefits to society are enormous," says Monticello. "Astronomy also is a very exciting area. It leads to our understanding of our origins and the origins of the universe."
Monticello is a Fellow of the American Physical Society and a recipient of the 2001 UT-Battelle Award for Scientific Research by a Team for research on the physics of plasma confinement in three-dimensional systems.
Submitted by DOE's
Princeton Plasma Physics Laboratory