2 Vol. 34, No. 2, 2001 1 Editorial: Basic Research 16 Modeling a Fusion Plasma at ORNL Heating Process and Stellarator 2 ORNL’s Search for Rare 22 Isotopes 17 Neutron Sources and Nanoscale Science 2 ORNL Theorists and the Nuclear Shell Model 18 Quantum-Dot Arrays for Computation 5 Beam Technologies Enable HRIBF Experiments 20 Carbon Nanotubes and Nanofibers: The 7 Neutrons, “Stripes,” and Self-Assembly Challenge Superconductivity 22 Incredible Shrinking Labs: 12 Weighing a Move to the ORNL’s Neutron Sources 8 Nanoscale and Nuclear Astrophysics 24 Basic Geochemical 10 Modeling Magnetic Mate- Research Supports Energy rials for Electronic Devices Industries 12 In Quest of a Quark: 26 Fermi Award Winner ORNL’s Role in the Opened New Fields in PHENIX Particle Detector 20 Atomic Physics 14 New Hope for the Blind 28 Improving the Internet’s from a Spinach Protein Quality of Service 15 Human Susceptibility and 29 QOS for Wireless Mouse Biology Communication This issue provides highlights of basic research at ORNL, including research on producing, characterizing, and finding applications for carbon nanotubes produced at ORNL by several techniques. The cover shows single-wall carbon nanotubes created by laser vaporization (note pink laser plume), which were then chemically purified and spray-deposited onto a substrate. The image above the cover image shows a carbon nanotube on electrodes, a possible nanoscale replacement for today’s microscale silicon transistors. See pp. 20-21 for a description of this and other nanoscale research. Images by Jason Fowlkes, Derek Austin, and Henrik Schittenhelm. Basic Research at ORNL Basic Research at ORNL: A Distinguished Past, An Exciting Future RNL has a time-honored tradition of basic research accomplish- ments in physics, chemistry, biology, and the materials sciences. In 1951 ORNL researchers were the first to confirm that a neu- Editor and writer—Carolyn Krause O tron decays into a proton, electron, and electron antineutrino. Assistant editor—Deborah Barnes ORNL biologists discovered the function of messenger RNA and the chromo- Editorial Board—Lee Riedinger (chair), somal basis for sex determination in mammals. This year the Department of Energy Fred Bertrand, Eli Greenbaum, recognized three ORNL discoveries as among the top 23 of DOE national labora- tories’ scientific accomplishments. They are nickel and iron aluminides for high- Russ Knapp, Reinhold Mann, temperature applications, ion beam techniques for making longer-lasting artificial Stan Milora, Thomas Zacharia hips and knees, and the Z-contrast electron microscopy technique, which produced Designer and illustrator—Jane Parrott Lee Riedinger the most detailed image of a crystal structure ever recorded in a microscope. Photographer—Curtis Boles In December 2000, an ORNL physical chemist, the late Sheldon Datz, received DOE’s prestigious Enrico Fermi Award for pioneering the use of crossed molecular beams to study the details of chemical reactions and for demonstrating ion channeling, The Oak Ridge National Laboratory in which charged atoms pass between a thin crystal’s rows of atoms. (See p. 26.) Review is published three times a year Our basic research tradition continues today, thanks largely to support from and distributed to employees and others DOE’s Office of Science. Much of the research, described in this issue, deals in a associated with or interested in ORNL. big way with very small features of matter ranging from quarks, electrons, photons, neutrons, and heavy ions to DNA and carbon nanotubes. By studying the properties of short-lived nuclei and searching for rare iso- Jim Roberto topes, using the Holifield Radioactive Ion Beam Facility, ORNL nuclear physicists Editorial office address: are gaining a better understanding of the origin of the elements and the mechanism Building 4500-North, M.S. 6266, of energy generation in stars. ORNL physicists and electronics experts have played a major role in devel- Oak Ridge, TN 37831-2008 oping electron and photon detectors and electronic components, to help search for evidence that the universe’s Telephone: (865) 574-7183; beginning has been mimicked in DOE’s Relativistic Heavy Ion Collider. FAX: (865) 241-6776; ORNL is well positioned to become the world’s leading center in neutron science with the comple- Electronic mail: [email protected] tion of our upgraded High Flux Isotope Reactor (HFIR) in 2003 and the Spallation Neutron Source (SNS) ORNL Review Web address: in 2006. Using neutron scattering at HFIR and elsewhere, ORNL researchers recently found evidence to www.ornl.gov/ORNLReview/ support a leading theory for explaining high-temperature superconductivity. Neutron data from another ORNL neutron source, the Oak Ridge Electron Linear Accelerator, is helping computational astrophysi- cists improve their understanding of nuclear processes by which isotopes are synthesized in stars. The SNS may also be used for this purpose. The Review is printed in the United The SNS will enable advances in characterizing nanoscale materials, such as triblock copolymers. States of America and is also available In other nanoscience efforts at ORNL, we are working toward fabricating nanofluidic lab-on-a-chip from the National Technical Information devices, conducting experiments with them, and predicting fluid behavior in them, as well. We are Service, U.S. Department of Commerce, devising innovative ways to trick nanoscale bits of matter into assembling themselves into useful products, 5285 Port Royal Road, Springfield, VA such as artificial membranes and electronic components. An ORNL team is designing a quantum-dot array 22161 that can be operated at room temperature to carry out innovative computations. As disk drives and transistors are further downsized, today’s materials will eventually reach limits in performance. We are addressing these issues through experimentation and computer simulation. Oak Ridge National Laboratory is DOE’s Office of Basic Energy Sciences has recommended managed by UT-Battelle, LLC, for the construction funding in fiscal-year 2003 for a proposed Center for Department of Energy under contract Nanophase Materials Sciences at the SNS. If Congress approves, the new center will integrate nanoscience research with our unique com- DE-AC05-00OR22725 bination of capabilities in neutron scattering, synthesis of new mate- rials, and theory and simulation, using supercomputers at DOE’s Cen- ter for Computational Sciences at ORNL. ISSN 0048-1262 Among its many uses, the Lab’s IBM supercomputer is being used to simulate a fusion heating and plasma control method involv- ing radio waves, as well as to model a future fusion device that may Rendering by John Jordan Oak Ridge National Laboratory is a be built here in a few years. This basic research is essential to devel- Artist’s conception of the proposed multiprogram, multipurpose laboratory oping fusion as a future energy source. To help make fossil fuel, Nanophase Materials Science Center. that conducts research in energy nuclear, and geothermal energy sources more economical for pro- production and end-use technologies; ducing power, our geochemists are performing important basic research. biological and environmental science In computer science, we perform basic research to enable computational researchers to get better results faster. Recently, an ORNL algorithm was shown to reduce and predict delays in data delivery over the Internet. and technology; advanced materials In the biological area, ORNL received a 2001 R&D 100 Award for its protein structure prediction synthesis, processing, and tool. ORNL basic research involving mice and their DNA may shed light on why some humans are more characterization; and the physical susceptible than others to getting cancer after exposure to low doses of radiation or environmental chemi- sciences, including neutron-based cals. Research being conducted at ORNL and the University of Southern California suggests that a spinach science and technology. protein might someday restore sight to the legally blind. Basic research has been a pillar of our work. As ORNL gets new facilities this decade for neutron science, computer science, nanoscience, and biology, an even brighter future is in store for fundamental research at the Laboratory. – Deputy Director for Science and Technology – Associate Laboratory Director for Physical Sciences Number Two, 2001 1 Basic Research at ORNL ORNL’sORNL’s SearchSearch forfor RareRare IsotopesIsotopes ORNL researchers are taking advantage of HRIBF’s special ability to make neutron- rich beams to allow studies of highly unstable nuclei not found on the earth. These studies may allow them to better understand the nature of nucleonic matter and the origin of elements in the cosmos. ur earth is home to 81 stable decay. Isotope half- elements, including slightly lives range from less fewer than 300 stable isotopes. than a thousandth of Several other elements (e.g., a second to billions thoriumO and uranium) and more than 130 unstable of years. Short-lived HRIBF has the largest tandem isotopes also exist on the earth, but all of them isotopes cannot be electrostatic accelerator in the eventually decay. That is, the atomic nuclei of these found naturally on world, which is located in isotopes eventually capture or emit electrons, the earth because ORNL’s landmark tower. positrons, or alpha particles, or they undergo spon- they have long since Jim Richmond taneous fission, making the isotopes radioactive. decayed in that our planet was formed about 4 bil- The properties