Development and Operation of National Research Facilities

Holifield Radioactive Ion Beam Facility
SHaRing Our Microscopy Expertise
Metrology Lab Measures Up
ORNL Helps the Metals Industry
ORNL is the home of 16 sophisticated experimental science facilities that are available to users nationwide and, in most cases, throughout the world. Twelve are officially designated by the DOE as "user facilities." Two new user facilities established in 1995 (and described in this section) are the Metrology Research and Development Laboratories and the Metals-Processing Laboratory User Center (Mplus).

These research facilities serve scientists and engineers from universities, industries, and other government laboratories, as well as ORNL staff. They simultaneously contribute to DOE missions and other national science and technology goals by minimizing unnecessary duplication of effort, promoting beneficial scientific interactions, and making the most effective use of costly and, in many cases, unique equipment.

The development and operation of these facilities require the broad interdisciplinary human and technical resources available at ORNL. These facilities are supported by specific elements of the research infrastructure ranging from atomic physics to genetics. They rely on operational expertise in diverse arenas such as research reactors, particle accelerators, bioprocessors, and extensive environmental research reserves. At various stages of a facility's lifetime, we provide expertise in design, engineering, project management, computing-data acquisition, and instrumentation, as well as resources to support user services and an administrative infrastructure.

Our facilities support DOE missions in basic energy sciences, nuclear physics, advanced materials development, biotechnology, genetics, environmental science and technology, and energy efficiency. The facilities offer a strong educational benefit; many graduate students use them in their thesis research, and interactions are increasing with school teachers and K-12 students. The facilities also provide direct support to help our many industrial users become more competitive.

Besides the two new ones, ORNL user facilities and centers include the Atomic Physics EN Tandem Accelerator, Bioprocessing Research Facility, Buildings Technology Center, High Temperature Materials Laboratory, Holifield Radioactive Ion Beam Facility, National Environmental Research Park, Neutron Scattering Research Facilities, Oak Ridge Electron Linear Accelerator, Shared Research Equipment, Surface Modification and Characterization Research Center, High Flux Isotope Reactor, Center for Computational Sciences, and Mammalian Genetics Facility (including the Mouse House).

Holifield Radioactive Ion Beam Facility:
User Center Will Reach for the Stars

The orbiting Hubble Space Telescope and Compton Gamma Ray Observatory satellites constantly beam down information from the stars. Soon researchers at the Holifield Radioactive Ion Beam Facility (HRIBF) will shed even more light on the life and death of stars by conducting down-to-earth experiments. HRIBF, which should be ready for its first experiments in October 1996, is the only U.S. facility dedicated to producing and accelerating intense beams of radioactive nuclei that occur naturally only in outer space.

Recently, the Compton Gamma Ray Observatory detected radioactive aluminum-26 in the cosmos. How? It measured the energies of gamma rays characteristic of the decay of aluminum-26. HRIBF researchers, using an ORNL cyclotron and the world's largest electrostatic accelerator, will be able to make measurements to understand how such elements are produced. For example, already physicists have determined the rate at which aluminum-26 is produced and the energy released in its formation by bombarding a stable magnesium-26 target with protons to make the radioactive isotope aluminum-26. Such information is of interest because heavier elements such as aluminum are formed in nova and supernova. However, in these spectacular stellar explosions many of the reactions involve nuclei that do not occur naturally on the earth, which has become increasingly stable over the past 5 billion years. Therefore, accelerated beams of radioactive nuclei are needed to provide data to understand many nuclear processes during stellar explosions. Such measurements using radioactive ions will be the forte of the HRIBF.

The remnants of Eta Carina as seen through the eyes of the Hubble Space Telescope. Such spectacular stellar explosions produced many elements and dispersed them to the cosmos. In the 1840s, this nova briefly was the second brightest star in the sky.

Element synthesis and energy generation during stellar explosions depend crucially on rates of thermonuclear fusion reactions in which radioactive nuclei are formed as isotopes capture protons; one such important reaction is the capture of protons by fluorine-17 nuclei to produce neon-18. However, because the relevant nuclei are radioactive, direct measurements of these reaction rates have not been possible at existing accelerators. For example, it is not known whether nova explosions produce only low-mass nuclei (up to fluorine) or also nuclei up to iron and beyond. Direct measurements of the rates of such crucial fusion reactions will help to resolve these discrepancies. The HRIBF will provide this important information.

About one-third of the HRIBF's work will be devoted to nuclear astrophysics using beams of, for example, radioactive fluorine, chlorine, and sulfur. One question that may be tackled is this: How are light elements up to iron synthesized through rapid hydrogen burning processes in binary star systems? In this process, a white dwarf, made of mostly heavy elements, pulls hydrogen away from an expanding red giant, resulting in a thermonuclear explosion that shoots jets of proton-rich heavy elements into outer space. Such processes are thought to be the largest thermonuclear explosions in the universe.

HRIBF's radioactive ion beams will be used for nuclear structure and nuclear astrophysics research.

Two-thirds of the research at HRIBF will be concerned with nuclear structure. Nuclear structure studies will include searches for short-lived deformed nuclei shaped like footballs, pears, cigars, and perhaps even bananas! These nuclei will be formed when a radioactive beam strikes a target. Heavy radioactive nuclei having nearly equal numbers of protons and neutrons (such as tin-100, a "holy grail" isotope) will be extra stable, enabling physicists to better understand the effects on nuclear structure of variations in neutron and proton numbers, as well as the limits of stability. Other nuclei will be quite unstable, enabling physicists to observe a new form of radioactivity—emissions of protons.

Carl Gross (left) and Chang Hong Yu inspect a recoil mass spectrometer that will help them decipher nuclear structure at ORNL's Holifield Radioactive Ion Beam Facility. Photograph by Tom Cerniglio.

No materials science research program has been established yet for HRIBF, but physicists there are hoping such a program will be supported. One proposed experiment would aim to make a diamond transistor. A beam of radioactive carbon-11 could be used to implant radioactive carbon-11 ions in a diamond target. After irradiation the diamond could be heated. The carbon-11 atoms would anneal into the diamond lattice as carbon, but after some hours they would all decay to stable boron-11. Thus, a substrate of boron could be produced in the diamond crystal. It is expected that such a diamond transistor could operate at very high power.

By the end of 1995, the HRIBF was completed on time and within cost with the help of ORNL's skilled crafts personnel. Two accelerators in the heavily shielded facility had to be reconfigured. Originally, Holifield's 25-million-volt tandem accelerator accelerated stable, heavy ions. If an energy boost was required, the Oak Ridge Isochronous Cyclotron (ORIC) provided it for ions exiting the accelerator. Now, the roles have been reversed. ORIC will slam an intense light-ion beam, such as protons or helium-3 nuclei, into a target. Collisions between projectile and target nuclei result in many radioactive products. After diffusing from the target, the desired isotope is magnetically separated from the other products. Atoms of this isotope are converted to negative ions, which are accelerated through the tandem as a radioactive ion beam. The accelerated radioactive ions will smash into a target, producing reaction products that can be measured in a variety of experimental stations at the HRIBF. Most of the radioactive beam experiments will probably use one of two new experimental stations, which are being constructed to select the very rare reactions of interest from the background of the beam and the products of less exotic reactions.

The astrophysics experiments will use the recently installed Daresbury Recoil Separator from England to measure the rates of fusion reactions between the incoming radioactive ions and hydrogen and helium targets. The nuclear structure experiments will use an even larger recoil mass separator together with a variety of detectors to detect and measure energies of gamma rays, protons, alpha particles, and eventually neutrons.

Paul Mueller (left) and Alan Tatum work on the 300-kilovolt Radioactive Ion Beam Injection Platform, where radioactive atoms are produced, ionized, and selected for injection into the 25-megavolt tandem accelerator. Photograph by Lynn Freeny.

In preparing the facility for experiments, tests have been performed to estimate how fast and efficiently a stable arsenic beam can be extracted from a germanium target bombarded by protons. A newly installed robot also has been tested. After the target ion source assembly becomes radioactive and a new target is needed, the robot will pick it up, put it in a cask, and place the package on a conveyor belt to be carried away. Then the robot will place a new ion source on the insulated, high-voltage platform.

Thirty-four letters of intent have been received from 99 researchers at 36 institutions in 17 states and 6 foreign countries proposing experiments at the HRIBF. The HRIBF user organization consists of about 300 scientists from the United States and 20 foreign countries. Experiments with radioactive ion beams are expected to start in 1997. As we approach the third millenium, the world can expect research results from a unique facility that should be of stellar quality.

The facility is supported by DOE, Office of Energy Research, Office of High Energy and Nuclear Physics.

SHaRing Our Microscopy Expertise

ORNL has gained visibility for its work with tools to image the seemingly invisible. Its Shared Research Equipment (SHaRE) program is one of four DOE electron microscopy facilities for materials science studies to receive support through the Presidential Scientific Facilities Initiative (funded by DOE's Office of Energy Research, Basic Energy Sciences, Division of Materials Sciences); the other ORNL facilities to win support from this $100-million initiative are the High Flux Isotope Reactor and the HRIBF. Because of the boost in funding for the SHaRE program, the number of users of the facility should double previous annual counts.

To characterize the structure, chemistry, and mechanical responses of materials and solve materials science problems, ORNL and outside researchers have been sharing a variety of SHaRE tools: transmission electron microscopes, scanning electron microscopes, atom probe field ion microscopes, atomic force microscopes, and mechanical property microprobes. Use of these microanalytical techniques has enlarged the Laboratory's reputation in materials sciences.

Our Shared Research Equipment program played a key role in the development of superconducting wire.

This view of ORNL's rolling-assisted biaxial textured substrate (RABiTS) was provided by the SHaRE program's new field-emission-gun scanning electron microscope. Diffraction patterns formed by electrons backscattered off the sample reveal grain orientations. From these data, grain boundary misorientations were calculated and shown by color coding. Because grain boundary misorientations in the sample are mostly less than 10 degrees, superconducting properties are effectively preserved.

We are a world leader in using atom probe field ion microscopy to do chemical analyses on samples with single-atom resolution. The three-dimensional atom probe concept developed at ORNL will provide the best and most rapid detection capabilities in the world. By imaging nickel aluminide alloys, we gain insights into how trace additions of boron and zirconium improve the alloy's properties. In the same way, we glean information on the role of copper-enriched precipitates in causing embrittlement in reactor pressure vessel steels and on the influence of neutron irradiation and thermal annealing on the steels' copper content.

A new field-emission-gun scanning electron microscope at the SHaRE facility has played a key role in the development of the foundation of a flexible superconducting wire that can carry considerable current (see the highlight on p. 40). The microscope maps texture (or grain orientation) by analyzing patterns of electrons backscattered from crystalline planes of atoms. Combined with other techniques available using the scanning electron microscope, this mapping capability can determine the relative orientation, composition, and surface topography of all crystalline grains in a solid sample and the location and interconnection of grain boundaries.

Using this instrument, we observed the relative grain orientations in some superconducting materials and compared them with measured variations in electrical conductivity in these samples. This information guided the development of a substrate, or textured template, with properly aligned grains for the base metal and overlying buffer layers. Our texture mapping showed that this substrate-buffer system forms a template on which atoms of the superconducting material deposit so as to form a continuous path for electrical current, increasing its current density. Because of the microscope's value to superconductor development, it was jointly supported by DOE's Office of Energy Research, Basic Energy Sciences, and DOE's Office of Energy Efficiency and Renewable Energy.

We know that little things mean a lot, and we SHaRE our tools and talents.

Funding for the project was provided jointly by DOE, Office of Energy Efficiency and Renewable Energy, Office of Utility Technologies and by DOE, Office of Energy Research, Division of Materials Sciences.

Metrology Lab Measures Up

You own a small company that needs precision measurement and testing equipment. But you can't afford to buy these instruments. Whom should you call? Try ORNL.

ORNL offers industry some of the world's best and most precise measurement instruments.

At the Metrology Research and Development Laboratories facility, mechanical engineer Ruth Anne Abston prepares a mass flow controller for testing by ORNL's prize-winning gravimetric calibrator, which measures gas flow rates. Photograph by Curtis Boles.

Our newly created Metrology Research and Development Laboratories facility, one of more than a dozen DOE user facilities at ORNL, is making some of the best and most precise measurement instruments in the world available to representatives of industry and universities. Use of our instruments enables small companies to expand their capabilities, but they also benefit large companies from around the nation.

We offer access to unique instrument arrays in research centers for developing and testing measurement and sensing technologies. Here you can measure temperature; flow rate for liquids and gases; light intensities and diffraction; and electromagnetic, acoustic, and ionizing radiation levels.

One unique instrument available is the gravimetric calibrator, a state-of-the-art device that can measure flow rate of any type of gas. Built for use by the semiconductor industry, it has been awarded an international patent and received an R&D 100 Award from R&D magazine in 1995.

We offer the capability to measure electrical noise that might interfere with operation of electronic systems. Such testing can be done at ORNL or at the user's own facility using portable monitoring equipment loaned by the Laboratory. We also have a facility in which a user can expose equipment to harsh industrial environments for long-term tests. Such experiments can be controlled remotely over the Internet.

The Metrology Research and Development Laboratories also offer more than 40 years of expertise to users. ORNL has more than 100 scientists and engineers who specialize in diverse areas of measurement and sensor technology. Many also develop new measurement and testing techniques. Our capabilities should measure up to industrial expectations.

ORNL Helps the Metals Industry

Although the U.S. metals industry is one of the most advanced in the world, there is still room for improvement. By taking advantage of specialized technical expertise and equipment at ORNL, for example, industry could find ways to use less energy and release less pollution in its processes, saving money and jobs and becoming more competitive.

Recently, a company in Georgia found that use of ORNL-developed nickel aluminide for rails in its walking-beam furnaces made possible the commercializion of this furnace technology. The furnaces are used to soften steel bars for making tools. Thanks to the high-temperature strength of nickel aluminide, the furnaces can provide rapid heating, using less natural gas and process cooling water. Because this technology reduces energy use and emissions, it should enable U.S. companies to be more competitive and to save jobs. This kind of assistance is available to the aluminum, chemical, forest products, foundry (metal melting and molding), glass, petrochemical, and steel industries. It is offered through the Metals-Processing Laboratory User Center (Mplus), a DOE user facility at ORNL.

Computer simulations of deformation (left) and solidification as a result of metal processes are some of the services of the Metals-Processing Laboratory User Center.

Our Metals-Processing Laboratory User Center should
help U.S. industry become more competitive.

To help industry adjust to rapid changes in the marketplace and improve products and processes, Mplus offers the services and equipment of its four centers:

The effect of a car crash on a dummy is simulated by the Intel Paragon XP/S 150 supercomputer at ORNL. Simulations of car collisions are performed for Mplus.

The Mplus Center provides industry with access to the expertise of our partners such as universities, other DOE laboratories, and internal facilities—the High Temperature Materials Laboratory (including the Residual Stress User Center), Computational Center for Industrial Innovation, and the Oak Ridge Centers for Manufacturing Technology. We make room for industry to help it compete.

The Mplus User Program is supported by DOE, Office of Energy Efficiency and Renewable Energy, Office of Industrial Technologies.

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