ORNL Review Vo-Dinh and His ORNL Colleagues Are Described Here

Home , Bertram Brockhouse

I COVER CAPTION I Rodney McKee of ORNL's Metals and Ceramics Division views a video camera image of a laser beam passing through a waveguide material he and Fred Walker developed. In front of the monitor screen are a laser, laser beam, waveguide sample, and camera. ORNL's development of a thin-film waveguide for possible use in tele communications and computers is described in the article beginning on p. 34. Photograph by Bill Norris.

The Oak Ridge National Laboratory Review is published quarterly and distributed to employees and others associated with or interested in ORNL. The address of our editorial office is Building 4500-South, M.S. 6144, Oak Ridge, TN 37831- 6144; telephone: (615) 574-7183 or (615) 574-6974; FAX, (615) 574-1001; electronic mail, [email protected] or pearcejw@ ornl.gov.

If you have changed your mailing address and want to remain on the mailing list, pl ease notify the editorial office.

Internet users can tind the Review at: http://www.ornl.gov/ ORNLReview/rev26-2/text/home.html

The Review is also available on microfiche at the ORNL Central Research Library.

The Review is printed in the United States of America and is also available from the National Technical Information Service. U.S. Department of Commerce, 5285 Port Royal Road, Springfield. VA 2216l.

ORNL is managed by Martin Marietta Energy Systems, Inc. for the Department of Energy under contract DE-AC05-840R21400.

ISSN 0048-1262

Editor Carolyn Krause Associate Editor Jim Pearce Consulting Editor Bill Appleton Designer Vickie Conner

Technical Editing Mike Aaron Electronic Publishing Bob Eldridge Larry Davi

Produced by the Information Management Services Organization Volume 27 Number 3, 1994 FEATURES

2 Reflections on Nobel Prize Winners

4 Advanced Photonics at ORNL: Shedding Light on a New Initiative William S. Key and John C. Miller ORNL has many light-research projects that are now under the Lab's new photonics initiative. SIDEBARS: Hybrid Optics: Two Complementary Lenses for the Price of One? Phosphate Glass for Photonics Single Dye Molecule Detected in Droplet Molecular Clusters, Laser Snow, and the Ozone Layer Photonics on the Production Line Illuminated Membranes Cleanse Groundwater Other Photonics Highlights at ORNL

24 Ultraprecision Manufacturing Technologies for Optics Brigham Thomas ORNL' s Star Wars work has led to the Ultraprecision Manufacturing Technology Center.

34 ORNL's Thin-Film Waveguide and the Information Highway Carolyn Krause ORNL's barium titanate waveguide for optical switches may boost data traffic on the information highway.

44 Early Signs of Environmental Damage and Recovery S. Marshall Adams Measurable changes in wildlife species can be early predictors of unwanted environmental and health effects, as well as indicators of ecological recovery in streams such as East Fork Poplar Creek. SIDEBAR: East Fork Poplar Creek: Signs of Ecological Recovery D EPARTMENTS 57 Awards and Appointments 60 Educational Activities-DOE' s High School Honors Program; superconducting motor at EnvironMENTAL Fair 64 Technical Highlights-Removing ink from waste newspapers; chemistry lab on a chip; radiation-hardened memory chip; fast-growing grass developed as biofuel feedstock; liquid-metal car engine conceived 72 R&D Updates-Two R&D 100 Awards for ORNL-developed technologies; recoil separator from England for Holifield Radioactive Ion Beam Facility; Oak Ridge Isochronous Cyclotron goal attained; study of effects of greenhouse gases on forests; ORNL-produced isotope in newly approved bone pain treatment 79 Technology Transfer-Neural-network software for predicting chemical properties; CRADA with Department of Transportation on data acquisition system for crash-avoidance research; medical isotope generator licensed to California firm; superconducting wire technology CRADA

Oak Ridge National Laboratory is a multiprogram, multipurpose laboratory that conducts research in the physical, chemica~ materia~ and life sciences; infusion, fission, and fossil energy; and in energy conservation and other energy-related technologies. That Nobel Feeling

determine the arrangement of ordinary and magnetic atoms in solid samples. This research opened the door to understanding magnets at the atomic level, leading to such developments as efficient magnets for motors and magnetic storage of information. Brockhouse also did his work at a national laboratory, the Chalk River Nuclear Laboratories in Ontario, Canada. These pioneering accomplishments, like those in high energy physics recognized by many previous Nobel Prizes, would not have been possible without national laboratories. The reason: these labs play an almost unique role in designing, constructing, and operating major facilities for science. The Shull-Brockhouse research is noteworthy for two reasons: it spawned neutron science, and the results of neutron science have had broad impact on other fields of science as well as practical implications for mankind. By my count, no fewer than eight Nobel Clifford Shull (right}, who with Ernest Wollan (left} pioneered reactor-based neutron prizes have been awarded for work in scattering at ORNL's Graphite Reactor, won the 1994 Nobel Prize for physics. He physics, chemistry, biology, and shared it with Bertram Brockhouse of McMaster University in Canada. Shull, recently materials science that benefited directly retired from the Massachusetts Institute of Technology, conducted much of his pioneering work in neutron scattering from 1946 to 1955 at ORNL. His ORNL from neutron science since Shull did his collaborators included Mike Wilkinson and his students included ORNL's Herb Mook, research. These winners are Glenn Ralph Moon, and Steve Spooner. Seaborg (1951); Louis Nee! (1970); Paul Flory (1 974); Philip Anderson, Nevill have always found it gratifying to and Bertram Brockhouse for their seminal Mott, and John Van Vleck (1977); observe the reaction of the scientific contributions to neutron scattering. Jerome Karle (1985); Johannes Bednarz I community when Nobel Prizes are Cliff Shull conducted his pioneering and Alex Muller (1987); Norman awarded. A grand feeling of warmth, work in elastic neutron scattering at Ramsey (1989); and Pierre-Gilles de sharing, and gratitude permeates the ORNL from 1946 to 1955 using neutrons Gennes (1991). entire scientific community much like from the Graphite Reactor. He came to The contributions of neutron science most people's reactions to acts of ORNL to join Ernie Wollan, who had to society range from medical isotopes extraordinary kindness or festive already constructed a diffractometer and for diagnosis and treatment, to electronic holidays. It is both humbling and started investigations to understand chips and magnetic recording media, to stimulating to see work by your peers neutron diffraction as a probe of the high-tech polymers and plastics. I am that uplifts the condition of mankind and atomic structure of solids. If Wollan were convinced that we scientists get a warm adds dignity to your own endeavors. still alive, he would almost certainly have feeling of pride over Nobel Prizes for Such is the feeling I experienced at shared in the prize. justifiable reasons.-Bill Appleton, ORNL on the awarding of the 1994 Wollan and Shull developed a method ORNL Associate Director for the Nobel Prize for physics to Clifford Shull for using patterns of scattered neutrons to Advanced Neutron Source.

2 Nobel Laureate Dies

ugene Paul Wigner, Nobel nuclear physics. His most notable laureate who strongly influenced contribution to nuclear physics was his E nuclear reactor development died visualization of the compound nucleus at the age of 92 on January l, 1995, at (entirely independently of Niels Bohr to Princeton, New Jersey. Except for stints whom the idea is usually attributed)." at the universities of Chicago and Oddly enough, according to Wisconsin and in Oak Ridge, he worked Weinberg, Wigner never bad a course in as a theoretical physicist and active physics. Born in 1902 in Budapest, faculty member at Princeton University Hungary, he received his doctoral degree from L930 to 1971. in chemical engineering in 1925 from In 1946-1947, Wigner was director of the Technische Hochschule in Berlin. research and development at Clinton His best friend was John von Neumann, Laboratories, predecessor of ORNL. He father of the modern computer who returned to ORNL for a year in 1964 to introduced him to mathematical group organize a civil defense research project, theory. When he came to Princeton, which became an early model of Wigner had an international reputation collaboration among social scientists and as a theoretical physicist. His first engineers in attacking complex issues. student was Frederick Seitz, who Wigner, who was present at Stagg worked at ORNL and later became Field in Chicago in December 1942 when president of the National Academy of the first self-sustaining nuclear chain Sciences and of Rockefeller University. Eugene Wigner reaction was observed, became concerned His second student was John Bardeen, (1902-1995) in 1939 that Nazi Germany would who helped develop the transistor and develop the atomic bomb before the Pressurized versions of the MTR became won two Nobel Prizes in physics. United States. He and Leo Szilard the predominant reactor type for During his directorship in Oak Ridge, expressed this concern to German submarine propulsion and commercial Wigner founded the Clinton Training physicist Albert Einstein, who dictated a nuclear power. In addition, he proposed School, which became the Oak Ridge letter in German to President Roosevelt the aqueous homogeneous breeder in School of Reactor Technology. Also, about the need for an American crash which the fuel, moderator, and coolant during his time at ORNL, the first project to develop the bomb before are combined as a fluid. This concept, reactor-produced radioisotopes were Germany did; Wigner translated it into embraced by former ORNL Director provided to a cancer research hospital. English. To develop an American bomb Alvin Weinberg, led to ORNL's His recruitment of Alexander Hollaender as fast as possible, he persuaded the development of an aqueous led to the formation of ORNL's Biology Metallurgical Laboratory in Chicago to homogeneous reactor and molten-salt Division, one of the world's strongest replace the proposed high-temperature, reactor for breeding fissionable uranium- centers of basic biology. Despite his helium-cooled reactor with his water 233 from thorium. Wigner and successes, Wigner thought he bad no cooled reactor concept. Wigner's reactor Weinberg coauthored the 1958 classic aptitude for administration and became was built by the DuPont company in The Physical Theory of Nuclear Chain increasingly frustrated with bureaucracy Hanford, Washington. Reactors. in Oak Ridge. Wigner also influenced development In his 1994 book The First Nuclear In a tribute to Wigner at ORNL on of reactors at ORNL, including the Era: The Life and Times of a January 9, 1995, Weinberg called him Graphite Reactor. He proposed the design Technological Fixer, Weinberg wrote of "my scientific mentor," "a person who of the Materials Testing Reactor (MTR), Wigner: "While in his twenties he cared," and the "patron saint of Oak developed at ORNL and built in Idaho. introduced the ideas of symmetry and Ridge National Laboratory." Joanne S. This reactor design was the basis for the group theory into quantum mechanics, Gailar, who worked with Wigner on designs of ORNL' s Oak Ridge Research an achievement for which he received civil defense in 1964, remembered him Reactor, High Flux Isotope Reactor, and the Nobel Prize in 1963. Later he was as "courteous, thoughtful, unpretentious, proposed Advanced Neutron Source. one of the founders of theoretical and lovable."

ight-or photons-is the key to many relevance and importance to other research recent developments at ORNL. Consider activities, and the significance of ORNL's L these example : accomplishments in the field. A new laser technique for nonsurgically What is photonics? According to the magazine diagnosing certain cancers. Photonics Spectra, photonics is "the technology of A much le s expensive test for detecting generating and harnessing light and other forms of polychlorinated biphenyls (PCBs) in radiant energy whose quantum unit is the photon. environmental samples u ing strips of chemically The range of applications of photonics extends treated paper that glow if they are exposed to from energy generation to detection to PCBs and then excited by ultraviolet light. communications and information processing." Those of us A thin-film light-wave guide that could be used Those of us working in this field believe it is one working in to make an optical switch to increase the amount of the most important fields of science at the of "data traffic" on the information superhighway. Laboratory. This belief is supported by indicators photonics A phosphate glas originally developed to such as the amount of photonics-related research believe it is isolate radioactive waste that shows promise for being performed at ORNL ($25 rnilJion annualJy), lenses and optical fibers for such uses as laser the number of Laboratory divisions involved (most one of the surgery. technical divisions), the number of researchers most Use of diamond turning, a precision-machining involved (more than 140), and the importance of important technique welJ-honed at the Oak Ridge Y-12 the accomplishments (a large percentage of Plant, to make better mirrors and lenses. ORNL's 82 R&D 100 awards have had significant fields of A spectroelectrochemical sensor that uses light photonics contributions). science at to detect groundwater pollutants. To provide a flavor of the breadth of local U e of a photon emission measurement photonics work, brief descriptions of current the technique to determine composition of materials research written by Carolyn Krause are presented Laboratory. as they are being produced for application in following this article. Two other articles published production process control in the metal plating, in this issue on photonics-related research are aluminum, and organic polymer industries. Brigham Thomas's article on the Ultraprecision Manufacturing Technology Center (seep. 24) and These developments and other research an article on ORNL' s development of thin-film performed at Oak Ridge National Laboratory waveguides (seep. 34). Previous issues of the related to lasers, lenses, optical fibers, fluorescent Review have covered photonics research. A partial materials, and special manufacturing technjques listing of Review articles on photonics research can be collectively referred to as photonics over the past four years appears on p. 21. technology. Scattered ORNL research related to Most of the photonics-related research at the light ha been brought under the umbrella of the Laboratory falls into three broad technical Laboratory's new Advanced Photonics Initiative. categories: materials and materials processing, In this way, we hope to highlight our capabilities process diagnostics, and environmental sensing. in a growing field deemed essential to More specifically, ORNL work is focused on development of new materials, energy and optical materials, laser materials processing, environmental technologies, information optical manufacturing, pectroscopy, advanced technologie , and manufacturing technologies to infrared and far infrared laser diagnostics, hybrid improve the nation' economic competitiveness. optical proce ing, image processing, In this i sue of the Review, we present the breadth environmental and physical sensors, and fiber of work being performed in photonics, its optic sensors.

Display of optical parts fabricated by the former Optics MODIL, now the Ultraprecision Manufacturing Technology Center at the Oak Ridge Y-12 Plant. The metal mirrors remain shiny after many years because they resist the formation of thick oxide layers that cloud surfaces.

Number Three, 1994 5 ADVANCED PHOTONICS AT ORNL: SHEDDING LIGHT ON A NEW /NIT/A TIVE

doing photonics research, (2) encouraging the formation of multidivisional project teams, (3) raising the awareness of our colleagues within DOE and industry concerning ORNL's rich capabilities in photonics research, and (4) helping to identify and secure new research programs in photonics. Although the initiative started with collaborations among the Health Sciences Research Division, the Engineering Technology Division, and the Instrumentation and Controls Division, it soon grew to encompass 10 divisions at ORNL, the Development Division at the Oak Ridge Y -12 Plant, and the Technical Division at the Oak Ridge K-25 Site. Thu , the Advanced Photonics Initiative has become an initiative of Martin Marietta Energy Systems, Inc., which manages the three Oak Ridge facilities for the Department of Energy. Recent actions have helped ORNL strengthen research programs in photonics and gain national recognition as a center of photonics re earch. For example, in December 1993, under the sponsorship of DOE, Tuan Vo-Dinh , a corporate fellow of Martin Marietta Energy an industry-laboratory workshop was Systems, Inc., demonstrates the use of his new method for held at ORNL on "Optical on-site testing for polychlorinated biphenyls (PCBs). Diagnostics in Manufacturing and Process Control." In January 1994 the Out of the Darkness Advanced Photonics Initiative received financial support from both the ORNL Executive Committee Until three years ago, few people at ORNL and the Oak Ridge Centers for Manufacturing were aware that so much photonics-related Technology. Although not yet singled out as a core research was being conducted at the Laboratory. competency, photonics is being recognized The rea on: the dispersion of these activities throughout Energy Systems as a key technical area. throughout many groups and divisions. In 1991, a Likewise, efforts to educate individuals and grass-roots effort was made to unify the organizations within Oak Ridge about our researchers working in the field through a significant photonics capabilities and to inform voluntary organization called the Advanced others through increased publications in trade Photonics Initiative. The purpose of this initiative magazines and newspapers are being carried out was to increase the Laboratory's visibility in the successfully. photonics field by (1) improving communications An additional objective of our efforts is to among individual researchers and research groups strengthen the infrastructure supporting photonics

6 Oak Ridge National Laboratory REVIEW Photonics is being recognized throughout Energy Systems as a key technical area.

Curt Maxey evaluates the patterns generated by interfering light beams from a point reference polarization interferometer to measure the curvature of mirrors and other optical parts during manufacture. research, an important consideration in these days continuing areas of R&D are flat panel displays, of scarce resources. Some benefits of improved high-definition television, optical information communications and networking stimulated by the storage, and optical computing. The economic initiative have been identification of resources impact of the technologies can be tremendou . For (such as lasers), resource sharing, and example, the opto-electronics industry has determination of future needs for photonics estimated that flat panel displays are the key related research. technology for products having an estimated market of $200 billion by 2000. Future Bright for The importance of photonics has been recognized by the Clinton administration and Studies of Light Congress for its positive impact on the U.S. The future for photonics at ORNL appears economy, job creation, defen e, and the promising, particularly when viewed in terms of environment. For example, one congres ional many new research and development (R&D) committee recently noted that "optics is a rapidly opportunities. Photonics is becoming an growing, highly diversified [field that is supporting increasingly important technology in all aspects of the] international economy" and that "the United our society. Examples of new applications and States is in the midst of an optics revolution."

Number Three, 1994 7 ADVANCED PHOTONICS AT ORNL: SHEDDING LIGHT ON A NEW /NIT/A TIVE

Within ORNL, photonics is closely aligned with the Southeast, uch as the Fiber and Electro-optics three other signi ficant Laboratory and Research Center at Virginia Polytechnic Institute Energy Systems initiatives: the Intelligent and State University, the Center for Lurnine cent Measurement Systems Laboratory, a new Materials at the Georgia Institute of Technology, instrumentation user center modeled after the and the Center for Re earch in Electro-Optics and Photonics High Temperature Materials Center; the Oak Lasers at the University of South Florida. ORNL's Ridge Center for Manufacturing Technology, network of photonics-related partnerships is has been which draws upon the manufacturing capabilities expected to expand. In the future, the Laboratory recognized of the Y-12 Plant and the R&D capabiliti e of plans to form ties with sister DOE laboratories, ORNL and the K-25 Site; and the proposed such a Sandia National Laboratories, where by the Environmental, Life, and Social Sciences photonics research complementary to that at Clinton Complex. Plans for this complex include building ORNL is under way. Beneficial partner hips with administration not onJy the Center for Biological Science but industry may also be forged through cooperative also the Biological Imaging and Advanced research and development agreements in areas and Photonics Laboratory. The newly formed such a pho phor coatings for flat panel displays. Congress for Biotechnology Center also will explore photonics The Laboratory shows strengths in three area technologies uch as biosensors. of photonics R&D- process diagnostics, its positive ORNL is also building external relationships to environmental sensing, and materials processing. impact on provide for its future in photonics. The It bas been forrning ties with other institutions the U.S. Laboratory, which is a member of the Alliance for involved in photonic research. Opportunitie in Optical Technology of Huntsville, Alabama, is a photonics are growing in ORNL rnis ion areas economy, job participant in the alliance's residence training such as energy and the environment. It is no creation, program in optics established through a U.S . wonder that as we look toward the future through defense, and Advanced Research Projects Agency award. the photonics tun nel, the light we see at the other ORNL is working with other photonics centers in end is very bright indeed. ~ environment.

8 Oak Ridge National Laboratory REVIEW Number Three, 1994 9

Such high-performance hybrid optics are expected to find uses in high-radiation or hazardous chemical environments.

efraction and diffraction may a hybrid-optics lens for use as a precisely curved surfaces. The rhyme, but ORNL sensor. This two-lens camera, he applications of diamond turning to Rresearchers are more says, performed as well as a manufacturing optics are being interested in making them work commercial camera with three studied at the Ultraprecision together in a lens than in a poem . refractive lenses. Manufacturing Technology Center The lenses in eyeglasses refract ''The advantage of the hybrid at the Y-12 Plant (see article on light. Light rays are bent as they approach," Sitter says, "is that the p. 24). pass into and out of the lens. The diffractive effects can compensate "Our plan is to use diamond focusing effect of the lens is used to for the undesirable effects of turning to make metal molds for Improve v1s1on. refraction. Each optic balances the lenses with the diffractive pattern The glistening three-dimensional other because they have opposite precisely cut into each mold," image that shows up on many dispersive behavior. For example, Miller says. "The plastic placed in credit cards when turned toward in refraction, blue light is bent more the mold will then pick up the the light is a hologram, an example than red light, but in diffraction, red diffractive pattern, forming a of diffraction. It is made possible by light is bent more than blue light. In hybrid optic having an arbitrary a specially etched pattern of fine addition, the diffractive element shape such as a sphere." lines that diffracts light as bands of may be designed to compensate for The group is also working with color. imaging aberrations, leading to an industrial partner, Geltech, Inc., Some photonics researchers at sharper images." of Alachua, Florida, to develop ORNL and elsewhere are seeking Hybrid-optic lenses are expensive hybrid-optic lenses made from novel applications for and to make because of the high cost of silica glass instead of plastic. To economical ways of making a lens microlithography. In this slow mass produce glass lenses, liquid that both refracts and diffracts light. tedious process, chemicals or glass will be cast in molds made Such lenses, which are now being reactive ions are used to etch by diamond turning. Fused silica made using an expensive process miniature patterns in a glass lens to offers several advantages over called microlithography, are called make it diffractive as well as plastic for hybrid optics: it is more hybrid optics. refractive. resistant to corrosive chemicals, "The idea is to take a light ORNL researchers are seeking to does not release gas molecules refracting lens and etch a pattern develop a less costly process of under vacuum, undergoes fewer on it that diffracts light," says David manufacturing hybrid optics. Bruce undesirable changes in dimensions Sitter of ORNL' s Instrumentation Bernacki and Curt Maxey, both of and optical performance resulting and Controls Division. "In this way, the I&C Division, and Art Miller of from temperature changes, and is one lens can do the work of two, the Oak Ridge Y- 1 2 Plant insensitive to ionizing radiation. reducing the size, weight, and cost Development Division are studying ·As a result, such high-performance of a lens system and eliminating the possible use of single-point hybrid optics are expected to find problems of aligning two lenses." diamond turning for fabrication of uses in high-radiation or One use for a single-element hybrid-optic lenses. Modern hazardous chemical environments "hybrid optics" lens might be to diamond turning is a computer on earth and in space. replace and improve the quality of controlled machining process that The lens of the future will likely lenses used to focus laser light in stems from work in the late 1960s be a "lens on a lens," with one compact-disc read-only memory at DOE laboratories. It was first being diffractive and the other (CD-ROM) drives for personal used to make sophisticated mirrors refractive. Once the cost of making computers. Such lenses could make for high-energy laser systems. It hybrid optics is lowered to a future CD-ROM drives smaller, uses a precisely contoured and reasonable level, thanks to lighter, simpler, and less costly. polished single-crystal diamond photonics research, two lenses Sitter has designed, built, and cutting edge that is driven by an may be available for the price of tested a miniature camera that uses ultrahigh-resolution machine to cut one.

11 none possible use lor phosphate gltisS itlay be in improved optical fibers for.la r The phosphate glass is also a promising material for lenses.

phosphate glass originally glass covered with a conventional displays and laser surgery. developed at ORNL to silicone-polymer cladding. They "Fluoride fibers used to carry Aisolate radioactive waste found that the fibers exhibited a infrared laser light to patients tend shows promise as a novel optical very high numerical aperture-a to be easily damaged by water material for collecting, delivering, measure of the largest angle at vapor," Allison says. ''We think the focusing, or amplifying light. One which incoming light can enter a ORNL glass fiber may be better possible use for phosphate glass fiber and pass through it efficiently. suited for this type of laser surgery, may be in improved optical fibers "For normal communication whose advantages over for laser surgery. grade fiber, this input angle may be conventional surgery include A phosphate glass containing only 1 2° from the normal of the reduced pain and faster healing." lead and indium, whose surface," Allison says. "High The phosphate glass is also a composition is based on that of a numerical-aperture fiber made from promising material for lenses. high-durability glass, was our phosphate glass can transmit "Because of the material's high developed and patented in the late light at incident angles of almost index of refraction, less curvature is 1980s by Lynn Boatner and Brian 70°. Thus, this fiber should be much required for a lens of a given Sales in ORNL' s Solid State better at collecting light from diffuse power," Allison says. ''The lower the Division. More recently, Boatner sources." curvature, the smaller the lens and Sales in collaboration with The ORNL researchers say the aberrations that can distort and limit Steve Allison of ORNL' s phosphate glass has great potential a lens' usefulness." Engineering Technology Division for use in specialized fiber sensors Thanks to its unique set of have fabricated optical fibers and for strain, temperature, and electric characteristics, ORNL' s new lenses from this phosphate glass-a field measurements and in light material may have a wide variety of good example of how delivery systems, including optical applications, making it one of the interdivisional cooperation can most interesting new optical glasses. advance research and development opportunities in photonics. Light "Our phosphate glass exhibits a unique combination of properties," Boatner says. "It has a high index of refraction and the ability to bend light at high angles. It is also Optical fiber chemically stable and durable. In addition, it has a low melting point and is transparent over a wide range of wavelengths. Perhaps most important, it readily dissolves rare-earth elements, so it can be used in developing new optically active devices such as fiber-optic amplifiers and new lasers." This drawing of an optical ~ber and incoming light compares the angles at which The ORNL researchers recently incoming light can enter a ~ber and pass through it efficientfy. Light can enter the tested optical fibers made at ORNL-developed ~ber from an angle of 67° compared with only 12° for normal Virginia Polytechnic Institute and communication-grade ~ber . Thus, ORNL's high-numerical-aperture (NA) ~ber can State University from the phosphate accept light from more diffuse sources.

13 DYE

technique ... could revolutionize ubrmensitive Mitce the droplet generator that p~ 0: miciodroplet of liquid in which a chemical dissGivea Single molecule of dye is illuminated by loserlaht. Fluorescence from the laser-excited measurement." dye mcitecule can be distinguished from light emitted by about a triltion molecules of solution. ''With this technique, we could have the world's smallest chemical test tube."

ingle molecules of a fluorescent chemical analysis is to measure trace molecules in a tiny drop of river water dye in microscopic droplets of chemical concentrations by counting and work upstream to determine the Ssolution have been detected by molecules in a very small sample of origin of the contamination." ORNL researchers. The laser-based solution. We have shown that one, two, Ramsey says the technique shows technique enables target molecules to or three-or no-molecules can be promise for carrying out fundamental be counted in very small volumes of detected in a tiny drop of solution." chemical experiments. 'We may be liquid, providing far greater sensitivity The ORNL scientists say that able to study chemical reactions than bulk analysis schemes. The ultrasensitive analysis can also be between single molecules in a technique could be used to characterize performed on materials that are not microdroplet," he notes. "Chemistry in a gene-containing material that may be normally fluorescent by attaching dye drop has the advantage of fewer responsible for inherited diseases or to molecules as fluorescent tags. For impurities, no container, and a very track flow of pollutants in rivers. example, detection of dye molecules small sample. With this technique, we The group at ORNL has conducted a attached to DNA molecules could could have the world's smallest chemical "needle-in-the-haystack" detection provide information on the sizes of test tube." experiment in which the fluorescence DNA fragments. If the dye molecules The key to the technique's success is signal from a single dye molecule is are attached at intervals along the the extremely small size of the liquid distinguished from light emitted by DNA strand, then the total fluorescence drop. "It is important to reduce the about one trillion solvent molecules. In signal can be related to strand size. number of solvent molecules as much as the experiment, a "microdroplet" Such information could be useful for the possible to decrease background produced by a device similar to an ink national Human Genome Project for emission from the solvent molecules," jet printer head is suspended in the understanding the genetic makeup of Whitten says. Filters, he explained, center of the analysis chamber. The humans and the origins of genetic separate light emission of one color droplet is then illuminated by the green disorders. (fluorescence from the molecule of light of a continuous-wave argon-ion Another important use of this interest) from that emitted by the drop's laser. technique is tracking pollutant flow in solvent molecules (Raman scattering). The dye molecule repeatedly absorbs rivers and locating sources. "As the As a result, the signal from the target the green laser light and then relaxes pollutant spreads out from the source, molecules is easily detected over the by emitting red light in individual the number of molecules concentrated noise of the solvent molecules, just as packets called photons. The photons in one place becomes smaller and the solo of a trumpet player standing at emitted from the dye molecules are then smaller," says Ramsey. 'With our a microphone is heard over the counted using a sensitive light detector, technique, we could detect a few background of numerous accompanying and the number of molecules in stringed instruments. the drop is determined roughly 7000 .------, The persistence of the droplet is by the number of photons also important. Whitten says that detected. 6000 - glycerin was selected as a droplet The technique was developed solvent because its low evaporation by Mike Barnes, Bill Whitten, rate causes it to exist a long time in and Mike Ramsey, all of the 5000 - the measurement apparatus. As a result, the target molecules remain Analytical Spectroscopy Section - 3 molecules of ORNL' s Chemical and § 4000 - in the laser light long enough for Analytical Sciences Division. Ill the maximum number of signal ~ Other collaborators in the project § 3000 - photons to be extracted. have been Steve Arnold of ~ 1 molecule The fundamental aspects of this (ii Polytechnic University of New c:: work were supported by DOE's .Ql 2000 - York (who developed the droplet (f) Office of Basic Energy Sciences. generator), Burt Bronk of the 1 molecule The U.S. Army supported a project 1000 - U.S. Army's Edgewood Research at ORNL to determine whether and Development Engineering single-molecule detection can be Center, and Kin Ng of California 0 _ no ~ used to detect minute traces of State University at Fresno. chemical or biological warfare "Our technique for detecting agents. Practical applications of the presence or absence of a single-molecule detection for Time (seconds) single fluorescent molecule (or assisting in detection of nuclear two or three such molecules) Fluorescence signals from 3 rhodamine molecules, weapons proliferation are now could revolutionize ultrasensitive 1 molecule, and no molecules were detected in being supported by DOE's Office chemical measurement," Ramsey suspended microdroplets by a technique pioneered of Nonproliferation and National says. "The ultimate goal of liquid by three ORNL scientists and collaborators. Security. 15 llesearc rs report the detection of a new form ollaser luster chemistry-the study of molecule, breaking it into an S+ ion and cluster like a molecular 'Poe Man,' interactions among closely a CS molecule and freeing an electron. creating bigger and bigger polymers packed atoms or molecules The S+ ion reacted with a nearby CS with each bite." C 2 ranging from 2 to 1000 in number-is molecule, forming an s; ion. This ion Miller and Desai use a high-power gatnering public as well as scientific then grabs a sulfUr atom from another picosecond laser to generate positive interest. One of the most exciting objects neighboring carbon disulfide molecule, ions of molecular clusters. They have of study is the duster of carbon atoms and so on. In this snowball effect, a also studied nitric oxide clusters mixed known as buckyball. Also intriguing to sulfur polymer as large as St2can be with other important species found in scientists are chemical reactions in a formed. Some carbon sulfide ions also the atmosphere. duster because they may imitate the latched onto neighboring carbon Carman's research focuses on processes of catalysis, materials disulfide molecules, forming polymers producing negative ions of clusters that synthesis, and atmospheric chemistry. as large as (CS)~. A mass spectrometer are then detected in a mass Clusters have been called the fifth detected the presence and masses of the spectrometer. In his technique, state of matter, after solids, liquids, sulfur and carbon sulfide ions. It also developed with C. E. Klots and Robert gases, and plasmas. The unique detected intermediate species that Compton of the same division, several properties of clusters fall between those provide clues to how these polymers are tunable lasers are used to excite the of single atoms and molecules and those formed. outer electrons of alkali atoms (e.g., of bulk solids. John Miller and Howard cesium). Each excited electron is very Carman, both of ORNL's Health far from the atomic nucleus and thus Sciences Research Division, have looks like a "free electron" to any applied novel laser-based techniques to nearby particle. If the cluster under the study of molecular clusters. study encounters such an electron, it One property of dusters has made it may grab it to form a negatively possible for Miner to identify a new charged duster ion, which is then torm of "laser snow." Laser snow was detected. In this way, Carman has first observed and named in 1975 by produced negative cluster ions of William Hopper of Columbia University carbon (C) -, cousins of the famous in New York City. He witnessed the fullerenes that include buckyballs. He precipitation of white particles after has also produced negative cluster ions exciting a gaseous mixture of cesium of nitric oxide, a species in polluted and hyarogen with a laser beam. The atmospheres. excited cesium atoms collided and It is now possible to generate in a reacted with hydrogen molecules, molecular beam apparatus microscopic producing a cesium hydride precipitate. dusters containing nitric oxides, sulfUr Laser snow was also detected in oxides, and chlorine-containing experiments with sulfur hexafluoride, molecules attached to a small number thiophenol, and carbon disulfide. of water molecules. The concentrations, At an April 1994 meeting of the sizes, and temperatures of these dusters American Physical Society, Miller can be experimentally varied. These reported the detection of a different "binary" clusters can serve as models form of laser snow by using a laser A laser beam ionizes a carbon disulfide for the study of atmospheric processes beam to ionize one molecule in a cluster (CS2) molecule, breaking it into an S+ in water droplets or ice crystals. of carbon disulfide molecules. This time, ion and a CS molecule and freeing an Recently, it has been observed that the proximity of the molecules to each electron. The 5+ ion reacts with a chlorine-nitrate reactions on ice crystals other in the cluster, rather than collisions nearby cs2 molecule, forming an 52+ in polar stratospheric douds convert between them, was responsible for the ion, which grabs a sulfur atom from inert chlorine into photochemically new form of laser snow. Another another neighboring carbon disulfide active chlorine (CI). Active chlorine is difference between this experiment and molecule, and so on. Thus, the initially thought to be primarily responsible for the earlier laser snow studies is that the ionized molecule "eats" its way through destruction of the earth's protective products of the chemical reaction are ozone layer. The energy of sunlight the duster like a molecular "Poe Man," ions that can be easily detected by mass converts the active chlorine to prOducts spectrometry. creating bigger and bigger polymers that stimulate ozone-destroying chain Miller, who collaborated with with each bite. reactions. University ofTennessee (UT) professor Miller and Carman propose to Charles Feigerle and graduate student Miller says that the cluster perfect the generation in the laboratory Sunil Desai on this work, says, mechanism eliminates the need for of these binary clusters. They hope to "Although visible particles were not collisions to induce chemical reactions. study the photochemistry of clusters of observed in our low-pressure 'When one member of a cluster of CS 2 chlorine-containing compounds on ice experiment, the mass spectrum revealed molecules is excited, it finds its next crystals to identify the products that the presence of sulfur and carbon door neighbor to be a suitable reaction lead to ozone losses. They also wish to sulfide polymers. These are the same partner and no collision is needed. Any explore binary clusters to gain species observed in earlier laser snow extra energy from the reaction can be knowledge about stratospheric sulfate experiments with high-pressure gases." used to eject weakly bound molecules and nitrate aerosols. The payoff could In the ORNL-UT experiment, the laser from the cluster. The initially ionized be better understanding of the beam ionized a carbon disulfide (CS) molecule 'eats' its way through the atmosphere through duster chemistry. 17 New photonic methods are imprcM,Ig manufacturing eHiciency. _ ___.

A fiber-optic Roman probe is used to analyze the composition of molten polyethylene. Such a tool is useful in industrial environments for characterizing products as they ore being produced. Real-time Raman analysis allows polymer composition to be adjusted during production.

hen sheets of metal are complex laboratory technique, to could benefit from improved control plated or plastic fibers the industrial environment. Through of composition during production. W are formed in large use of this technique, the Such control could be achieved by quantities on the production line, composition of many industrial relaying the real-time results of the actual composition of these materials can be monitored in real Raman analysis to a computer materials is not known until after a time on the production line. In programmed to adjust the batch has been produced and addition, the production process production process in response to analyzed. If part of the batch has can be controlled while materials messages about compositional the incorrect composition, it is are being produced rather than variations. discarded. Then the production after a batch is completed. How would this technique be process is altered to correct the "Timely control of production useful in the polymer business? composition for the next run. offers several advantages," According to Wachter, "Physical Production could be made more Wachter says. "They include properties of organic polymers, such efficient by determining the improved product consistency, as flexibility or hardness, are often composition of industrial materials reduced waste generation, and determined by varying the during manufacture, detecting increased energy efficiency. These proportion of constituents compositional variations, making improvements will help maintain incorporated during fabrication. midproduction corrections, and industrial profitability in a Traditionally, components have been otherwise controlling the process to competitive global marketplace." added at roughly the desired levels, achieve the desired composition. In Raman spectroscopy is based on and then the batch is analyzed after this way, a larger percentage of the the Raman effect, discovered by the production. If the composition is not products would meet customer Indian physicist C. V. Raman in correct, the batch often must be requirements, reducing waste, 1928. In this phenomenon, light of scrapped. Real-time Raman analysis saving money and energy, and a single frequency (color) is allows polymer composition to be increasing the competitiveness of scattered by each target molecule in monitored and adjusted during American industry. a transparent medium. The production to avoid errors in New photonic methods for scattered light undergoes a change formulation of the final product." improving manufacturing efficiency in frequency based on the Although current local efforts are are being developed through a characteristic energies of rotation focused on these applications, the collaborative effort among ORNL, and vibration of each target lessons learned can be applied to the Y-12 Plant, and the University of molecule. In Raman spectroscopy, numerous other industrial needs for Tennessee at Knoxville (UTK). the measured intensities and measurement. "Raman analysis is an Principal investigators are Eric frequencies of scattered light are extremely flexible method that can Wachter, a physical-analytical used to identify and quantify solve complex characterization chemist in ORNL' s Health Sciences different molecules in the medium. problems in a timely and cost Research Division; Jennings Cline, a The ORNL, Y-12 Plant, and UTK effective manner," Wachter says. physical-analytical chemist in the team are hoping to find "The different backgrounds and Development Division of the Y- 1 2 applications for Raman analysis in capabilities of the ORNL-Y-12-UTK Plant; and Marion Hansen, a the metal plating, aluminum, and team have proven critical for professor of chemical engineering organic polymer industries. These effectively and rapidly applying at UTK. areas were selected as a result of Raman spectroscopy to industrial This research team is adapting discussions with industrial problems. We expect further Raman spectroscopy, normally a representatives. Such industries successes."

19 ILLUMINATED MEMBRANES CLEANSE GROUNDWATER

ecause of its ability to remove along a 25-centimeter ( 10-inch) grease and dirt, trichloroethylene length. (TCE) was once used by nearly "A practical groundwater B Ground level every metal machining shop, remediation system will contain a automotive repair shop, and dry bundle of membrane tubes," Water level cleaner in the United States. Since Stockdale says. "Each tube will be 1976 environmental regulations have illuminated by a fiber split out from a Relief valve greatly raised the costs of TCE disposal, for controlling fiber bundle coming down from the so its use has been discontinued. trans-membrane surface. Contaminated water will be pressure However, because some of the TCE pumped into the membrane by a used widely in the past was released to small submersible pump, and clean the environment, it is now one of the water will be returned to the aquifer." Clean Clean most commonly found contaminants in water water (See drawing.) groundwater. Among its resting places Such an in situ remediation system are most Department of Energy sites. will be designed for long-term In hopes of cleaning up groundwater unattended operation. It could be used Water and Submersible and process streams contaminated with volatile organic ____. pump to purify industrial process and waste TCE and other volatile organic compounds streams to protect the environment. compounds, Oak Ridge K-25 Site The K-25 Site researchers have scientists are testing the use of special Schematic of a cleanup module. been testing membranes under inorganic membranes illuminated by various flow and illumination near-ultraviolet (near-uv) light. In this conditions. Their goal is to improve scheme, the contaminated water is close contact with the active surface as the photocatalytic process so that circulated through membranes in a the stream flows through the visible light will be effective. cleanup module. The membranes both membrane. Other photocatalytic "If visible light could be used," filter the water and destroy TCE remediation schemes have attempted to Stockdale says, "it might be possible molecules through a photocatalytic overcome this 'contact' problem but are to develop a solar-powered device. interaction on the surface. Specifically, less successful. One method disperses Sunlight would be used by solar cells when photons of near-uv light interact the photocatalyst into the process to power the water pump and by the ) stream, but the photocatalyst must be with a titanium oxide (Ti02 membranes to break apart pollutants. photocatalyst on the wet membrane added and then filtered out. Another Currently, only 1% of sunlight falls surface, active sites are created that method coats the photocatalyst onto within a wavelength band suitable for break down TCE into benign molecules. surfaces surrounding the process photocatalysis. However, a field of The membranes were based on stream, but ensuring good contact implanted solar-powered devices technology developed for separating between contaminants and the active might enable the use of natural uranium isotopes. The K-25 Site has surface is difficult." sunlight to decontaminate been a center of inorganic membrane The researchers have proposed groundwater." research for many years. The building a cleanup module and This work is partly supported by technology can be adapted to fabricate lowering it into a contaminated DOE's Environmental Restoration and new classes of membranes that are of underground aquifer through a vertical Waste Management Program. no value for uranium enrichment but borehole at a DOE site. A mercury arc Developers of the system are have enormous commercial value for a lamp at the surface will supply near-uv Stockdale, Douglas Fain, and Brian variety of uses. light to an optical fiber. The fiber will Bischoff, all of the Membrane "A key advantage of the carry the light down to the cylindrical Technology Department of the photocatalytic membrane," says John membrane where it would emit a cone Technical Division, K-25 Site, which is Stockdale, a developer, "is that the of near-uv light into the interior of the managed by Martin Marietta Energy contaminant molecules are brought into membrane, illuminating it fairly evenly Systems.

20 HE

HIGH~

ORNL researchers have helped clevel a new laser technique Tuan Vo-Oinh has developed surface-enhanced Raman optical data slorage (SERODS), which may enable industry to create compact for discs capable of storing more than a million 300-page books. The technology was recently licensed to SEROTECH, a sister company to nonsurgically World Library Inc., in California. diagnosing certai11 n the past four years, ORNl at the center can determine whether a researchers have worked on tumor in the esophagus is malignant or many projects that are now noncancerous {see "Nonsurgical Laser categorized as photonics-related Technique Detects Cancerous Tumors," research. Achievements in photonics Vol. 26, Nos. 3 and 4, 1993, p. 46 . previously covered in the ORNL Review Vo-Dinh and his ORNL colleagues are described here. also have developed a much less ORNL researchers led by Tuan expensive test for detecting Vo-Dinh of the Health Sciences polychlorinated biphenyls (PCBs) in Research Division and researchers at environmental samples (see "On-Site the thompson Cancer Survival Center Test for PCB Contamination, Nos. 3 in Knoxville, Tennessee, have and 4, 1993, p. 46). The test uses strips developed a new laser technique for of chemically treated paper that glow if nonsurgically diagnosing certain exposed to PCBs ond then excited by cancers. Using ORNL's special data ultraviolet light. In 1994 this analysis method and laser r ht for development received an R&D 100 "optical biopsy" diagnosis, hysicians Award from R&D magazine.

21 //Using lasers and mass spectrometers, ORNL scientists are detecting structural and chemical changes in small fragments of DNA."

Another development by Vo-Dinh's Dosimeter badges now in use at pulsed power switches, particle group is surface-enhanced Raman Martin Marietta Energy Systems, Inc., detectors, and insulating gases for optical data storage {SERODS). This are the products of a thermoluminescent underground transmission of electricity laser-based technology, which has dosimetry {TLD) system developed (see "Chasing Electrons in Gases and been licensed to a local company, uses jointly by ORNL and Y-12 Plant Liqu ids," Vol. 24, Nos. 3 and 4, 1991, the light-emitting properties of researchers. The TLD system p. 9) . molecules to pack considerably more automatically measures the amount and An optical sensor using two beams information onto compact discs. When type of ionizing radiation to which of laser light that can help monitor fu lly developed, a 12-inch SERODS personnel and the environment are reactor performance has been disc should be able to store information exposed. It also analyzes, stores, and developed by Marc Simpson of the from 18,000 sets of the Encyclopedia reports this information (see "Radiation Instrumentation and Controls Division Briffanica {see "ORNL Concept Would Dosimetry System," Vol. 23, No. 3, {see "Sensors for Health and Safety," Greatly Increase Optical Data Storage, 1990, p. 7 4) . Vol. 24, Nos. 3 and 4, 1991, p. 39). Vol. 23, No. 1, 1990, p. 85). Brian Sales and Lynn Boatner in the ORNL researchers led by Mike Cates Vo-Dinh also developed a surface Solid State Division have found that a in the Engineering Technology Division enhanced Raman scattering {SERS) higher degree of disorder is present in have found that fluorescence from technique for measuring concentrations a crystal surface bombarded with ions phosphorus on hot surfaces in of chemical contaminants in water, soil, than in a glass sample of the same operating centrifuges and engines can and wastes. This technology was composition. The work helps scientists reveal surface temperatures (see "New licensed to a California company (see better understand disordered solids and Light on Measuring Temperature," Vol. "SERS Technology Licensed to their effects on light transmission 24, Nos. 3 and 4, 1991, p. 46). GAMMA-METRICS," Vol. 24, No. 1, (see "Differing Structures of Amorphous ORNL' s Doug Mashburn has worked

1991 f p. 62). Solids," Vol. 23, No. 4, 1990, p. 19). with Neocera, Inc., to develop a A sensitive high-tech SERS probe Using lasers and mass spectrometers, software-driven, pulsed-laser system for combining a computer, laser, optical ORNL scientists Bob Hettich and depositing high-temperature fibers, and a power supply has been Michelle Buchanan in the Chemical and superconducting films of a desired developed at ORNL to detect trace Analytical Sciences Division are composition and thickness. Mashburn's pollutants in groundwater. In field tests, detecting structural and chemical own elaborate laser ablation device the probe detected the groundwater changes in small fragments of DNA shows promise for making thick contaminant trichloroethylene at levels (see "New Way To Detect Changes in superconducting films for use in wires as low as 150 parts per million (see DNA," Vol. 23, No. 4, 1990, p. 56). In and for synthesizing new materials and "New Probe Detects Trace Pollutants in the Health Sciences Research Division, better phosphor coatings for flat display Groundwater," Vol. 26, No. 2, 1993, C. H. Chen and his colleagues have panels (see "Cooperative Agreement p. 65). used laser mass spectrometry to for Automated Film Deposition by Another ORNL invention has been a measure the masses of DNA molecules Laser," Vol. 26, No. 2, 1993, p. 68, solar-powered "tracking" microchip and their ions up to 130 chemical and "Laser Ablation: Opening Doors to smaller than a penny that emits an bases in length. This system offers the New Materials for Industry" Vol. 27, infrared signal. In addition, a receiver potential for rapid sequencing of DNA Nos. 1 and 2, 1994, p. 40). for detecting the microchip's signal bases to determine the composition of ORNL has evaluated technologies for from a distance at least twice as far as human genes {see "Lasers Accelerate making optical mirrors originally can be sent by other transmitters of DNA Sequencing," Vol. 26, No. 2, needed by U.S. defense programs to comparable size has been devised and 1993, p. 58). direct beams of light and particles tested. The transmitter and receiver ORNL researchers led by Loucas toward military targets in space. These have agricultural and military Christophorou in the Health Sciences technologies, which are of interest to applications {see "Infrared Microchip Research Division have studied the the optics industry, include single-point and Signal Receiver Being Developed," behavior of electrons in matter. diamond machining that cuts metal at Vol. 23, No. 2, 1990, p. 56). Applications of such knowledge include precise angles to get the correct mirror

22 ' .. . Doug Mashburn's elaborate laser ablation device shows promise for making thick superconducting films for use in wires and for synthesizing better phosphor coatings for flat-panel displays. curvature. Such technologies, which Optics MODIL CRADA with UTOS," were developed at the Y- 12 Plant for Vol. 26, No. 1, 1993, p. 73; and making weapons components, are now "Diamond Tools Evaluated for SDIO being shared with industrial partners Mirrors," Vol. 26, No. 1, 1993, p. 76). through cooperative research and In short, ORNL researchers have development agreements (see "ORNL been working on a variety of photonics Evaluates Technology for Optical related pro jects. Clearly, ORNL has Mirrors," Vol. 23, No. 4, 1990, p. 59; been gaining expertise in this new area "CRADA on Precision Optics," Vol. 25, of science and technology while using No. 1, 1992, p. 91; "New Oak Ridge its resources to solve problems in the CRADAs for SDI Optical Systems," Vol. information, energy, and environmental 26, No. 1, 1993, p. 73; "Second fields .

o help make the United States more system integrators, and product users talk to each competitive in world markets, the U.S. other early in the product cycle. The SDI goal was T optics industry needs new technologies for to identify potential bottlenecks to introducing a flexible production of optical components ranging new product into the marketplace and to expedite from contact lenses to giant mirrors. America's solutions to these problems. smaller companies, in particular, fmd it risky to In 1988 the Optics MODIL was located at the develop new manufacturing techniques and Oak Ridge Y -12 Plant (in an ORNL division) to expensive to implement them. Government develop and "prove" the effectiveness of new industry-university collaborations in manufacturing processes for making optical parts. manufacturing technology are needed now, just as they were The Optics back in the mid-1980s when MOD/Lwas the Ballistic Missile Defense Organization of the Department located at of Defense (DOD) established OakRidge to a new type of manufacturing "prove" the research center at federally funded facilities. These effectiveness Manufacturing Operations of new Development and Integration Laboratories (MODILs) manufacturing allowed industrial firms with processes for limited resources to perform making research and development for new products while providing optical parts. DOD with affordable, high tech weaponry components. The MODIL in Oak Ridge (now called the Ultraprecision Manufacturing Technology Center) has become a model for a new Department of Energy (DOE) effort to Bri gham Thomas shows then Senator Gore optical components manufactured using preci sion machining at the Optics MODIL in Oak improve the competitiveness of Ridge. Following congressional hearings on the Hubble Space the U.S. precision machining Telescope problem, Gore was especially interested in Oak Ridge's industry. efforts to certify opti cs before they left the fabri cating machines. Looking Back

The MODIL concept centered around the The Y -12 Plant had already used such processes "concurrent engineering" approach to to fabricate mirrors that sent beams of light from manufacturing defense systems, specifically for the earth to mirrors on satellites to communicate DOD' s Strategic Defense Initiative (SDI) messages and pictures around the world. Organization. In this approach, raw material The mission of the Optics MODIL was to suppliers, designers, manufacturing engineers, develop and validate the manufacture of high-

Then Senator Albert Gore, now Vice President of the United States, inspects an Optics MODIL mirror while Gordon Fee, now president of Martin Mari etta Energy Systems, looks on.

Number Three, 1994 25 UL TRAPRECISION MANUFACTURING TECHNOLOGIES FOR OPTICS

States. For example, the Optics MODIL worked on developing better optical mirror for directing beams of light and particle toward military targets in space. Some mirrors were to be u ed to guide light from enemy launch sites and missiles in flight to detectors that signal interceptor systems to destroy enemy targets. As these high risk-high benefit technologies became available, the preci ion optics community incorporated them into their manufacturing processes. The U.S. military benefited from the A lightweight structure and a precision-machin ed surface are typical increased capabilities e tablished features of mirrors used in military systems. at their suppliers' facilities. The result was a "win-win" situation for both industry and government. Oak !Qdge was a logical site for the Optics MODIL; the extensive experience with precision machining at the Y-12 Plant and the collegial atrno phere of ORNL combined to provide a neutral ite where firms could develop technologies while protecting proprietary information. This new government-industry relationship did not come easily, though. When the MODIL concept was introduced, many comparties looked at Oak Ridge as Joe Cunningham adjusts a diamond turning machine used to cut competition. Some companies had aluminum and other metals to make precisely curved optical heard the phrase "we are the components. government, and we are here to help" too many times! But when precision telescope components, such as mirrors, the program ended five years later, our industry windows, lenses, and baffles (optical parts having partners made comments such as" ... (the Optics porous surface textures that keep unwanted light MODIL) brought together some of the leading from bouncing, or scattering, onto mirrors) for optics engineers in the country and fostered real, DOD's SDI ("Star Wars") program. These rather than guarded, dialogue toward solving some components were considered fundamental to the of our mutual production problems" and "(we) Star Wars defense concept because of their ability found the Optics MODIL to be an important forum to assist in the early detection of and defense for technology transfer, industry capability, and against missiles launched toward the United government program directions."

26 Oak Ridge National Laboratory REVIEW Passing the Torch of Technology The Optics MODIL management believed that technology transfer could best be achieved as a "contact sport" in which industrial researchers visit the site of the government researchers for hands-on activities. Thus, the Optics MODIL entered into seven cooperative research and "The Optics development agreements MODIL (CRADAs) with industrial firms. In fact, the Optics fostered real MODIL had the highest per dialogue capita number of CRADAs toward in Oak Ridge for a short Troy Marlar observes a ductile grinding machine as it shapes a spherical time. solving some section of a silicon carbide mirror substrate. The MODIL also of our provicied sponsor hip for university professors mutual interested in performing engineering research at together" design, and optical scatter production industrial locations. This on-site activity helped measurements. problems." mesh representatives of the industrial and The workshop on environmental controls was academic communities. especially helpful to our industrial partners. The MODIL sponsored numerous industrial Precise control of a diamond turning machine's briefings and workshop to bring together various thermal environment is one of the most important companies and organizations in the optics factors in fabricating high-accuracy components community. Industrial briefmgs were held twice a such as precisely curved mirrors. Temperature year at various locations around the nation to variations are detrimental to the final product provide small businesses on limited budgets an being machined, just as temperature variations opportunity to attend. Between 100 and 150 and thermal mismatches make it difficult to persons attended-a sizable representation of the un crew a mayonnai e jar lid after it's been in the precision optics industry. One day of the briefing refrigerator. was devoted to an overview and tour of the host It came to our attention that many of our facility, providing an opportunity for members of industry partners did not recognize the importance the optics community to gain insights into the of temperature control. This problem hit home operations of other companies, including their when investigations into a poorly machined part competitors. revealed that a manufacturer's diamond turning Workshops were held as needed to help focus machine was located directly under an air MODIL efforts on "burning issues." By limiting conditioning vent. attendance to key decision makers, tangible The Optics MODIL had a workshop to solutions to industry-defmed problems resulted. showcase our maunfacturing cells built using off Problems were solved in such areas as the-shelf equipment at a materials cost affordable environmental controls, diamond tools, "snap- to small business. The cells are designed to

Number Three, 1994 27 Kathy Hylton mounts an optical component in preparation for ion beam milling to shape precisely curved surfaces.

To determine the problems these companies had encountered in making the product, the Optics MODIL sponsored a Lessons Learned Workshop. Incredibly, representatives of the two companies told their competitors what they did wrong (hind ight is 20/20) The and what they would do differently the next time. By workshop on the beginning of the second environmental day of the workshop, the controls was interactions among attendees were astounding; especially it was almost like being at a helpful to revival. Confessions were made such as "we should our Joe Cunningham (left) and Art Miller check a device used to measure not have tried to polish the industrial the shape and curvature of a mirror produced by diamond turning at the mirror so early." And partners. Optics MODIL. support was offered. "Yes, we've made that mistake control the temperature to within a tenth of a before," said one attendee, "and this is how we degree, enabling the manufacture of ultraprecise corrected it." This workshop proved that components. The workshop participants took back competing firms can work together toward the to their companies information on building common goal of improving their collective manufacturing cells to suit their needs. position against foreign competition. One unprecedented workshop on lessons Because technology transfer was one of the learned was held early in the program. The Optics major thrusts, we were innovative and proactive MODIL wanted to determine the optics industry's in pursuing effective means of transferring capabilities for manufacturing precisely curved, information that would be most beneficial to our lightweight mirrors. Industry's response ran along industrial and academic partners. Our approach the lines of "send us the money and we can make was sometimes to "do first and ask later!" it." Because precision optics were typically made For example, we did not ask permission from under cost-plus contracts on a best-effort basis, our sponsor or DOE for a third party to host a that response was the norm. So the Optics briefing on issues of interest to the optics MODIL put industry to the test by requesting industry. Instead, we approached companies, mirrors with a defined specification, at a fixed universities, and other government laboratories price, with a defined delivery date. The two and asked if they were interested. They were companies that were awarded the contract worked more than willing to host an industrial briefing diligently to produce the ordered pieces. and showcase their facilities. These hosts However, both companies delivered mirrors that included, among many others, the universities of failed to meet our specification. They had to Alabama and Arizona, North Carolina State absorb most of the cost as a result of unexpected University, the National Institute of Standards overruns, and they were late in delivering the and Technology, Hughes, Martin Marietta, and mirrors. Lockheed.

28 Oak Ridge National Laboratory REVIEW

UL TRAPRECISION MA NUFA CTURING TECHNOLOGIES FOR OPTICS

state of Arizona to 0.6 meter (2 feet). Accuracies like that are needed in military satellites deployed in space to detect missiles launched from the earth's surface. Ductile grinding is a precision method for machining brittle ceramics by shearing material off the surface. Materials such as silicon carbide and sapphire can be machined with minimal The Oak subsurface damage. The Optics Ridge MODIL worked cooperatively with university and industrial facility is partners to develop an acoustic unique Curt Maxey aligns a paraboloidal segment of a beryllium mirror in emission technique to "listen" laser light to measure the quality of its shape. The interfering light to the process. When machining because it beams fro m the laser interferometer are used to map imperfections parameters are not ideal, cracks demonstrates in the mirror su rface. and chip form in the surface of integration the material. The sound of a The Technology propagating crack can be detected, just as the of these cracking of a fine china plate can be heard. The manufacturing Some technologies employed at the Y-12 Plant potential benefit to industry of this manufacturing for making precisely curved mirrors for lasers technology is the ability to use acoustic feedback technologies have been used for manufacturing optics by the along with machine controls to automatically to produce Optics MODIL and its successor, the maintain a more favorable ductile-shearing mode parts right Ultraprecision Manufacturing Technology Center. of operation. These technologies are described here. Ion beam milling uses ions in gas to shape the first time. Single-point diamond turning is a computer surfaces. The ions, acting like billiard balls, controlled machining process developed in the knock atoms off the surface of a material. Users late 1960s at DOE laboratories and first used to of this technique can improve a surface to an make sophisticated mirrors for high-energy laser accuracy of 1/20 wave. This level of precision is systems. It uses a gem-quality diamond in a lathe equivalent to creating a state of Arizona that has type action to create a precisely shaped, smooth no point higher than 12.7 centimeters (5 inches) surface on a part, eliminating the time-consuming, above the ground surface! unreliable step of polishing. Thanks to the Rank All three of these manufacturing techniques are Pneumo Nanoform 600 machine in Oak Ridge, available in industry in one form or another. complex-shaped surfaces can routinely be However, the Ultraprecision Manufacturing generated to an accuracy of 114 wave (wavelength Technology Center in Oak Ridge is the only = 0.633 micrometers) in aluminum, copper, nickel facility in the United States that has all three plating, and numerous other materials. To capabilities under one roof. The Oak Ridge illustrate this machine's precision, consider a facility is unique because it can demonstrate the typical mirror that is 12.7 centimeters (5 inches) integration of these manufacturing technologies in diameter and has a surface accuracy of 114 to produce parts right the first time, eliminating wave; this accuracy is comparable to limiting the the need for rework or for scrapping a defective elevation of the highest mountain peaks in the part.

30 Oak Ridge National Laboratory REVIEW A key to integrating these manufacturing techniques is on process characterization. In industry, an optical component is typically generated on the machine, removed, and then taken to another facility for inspection. If the part does not meet specification (e.g., the shape is not right), it must be remounted on the machine and reworked. This approach is time consuming, expensive, and not always successful. The Oak The center's Ridge center promotes on process inspection to verify the resources are accuracy of the part while it is being applied still on the machine, thus Maxey demonstrates the stability of a vibration-free polarization to medical, improving the manufacturing shearing interferometer. This robust machine helps solve a variety of efficiency and reducing the cost high-resolution measurement problems in manufacturing environmental, of optics manufacturing. environments. and An exampl.e of our support of on-process inspection is the development by one having fun on the job have been among the top electronics industry partner of a revolutionary tabletop contributing factors to this successful program. enterprises. scatterometer that can determine light-scattering properties over wide angles in real time. A New Mission Applications for this instrument include rapid nondestructive testing of magnetic and optical DOE recognizes that the research talent, disks, machined parts, and laser printer drums. manufacturing expertise, and fully equipped The Optics MODIL commonly awarded facility developed by DOD's Optics MODIL subcontracts (as in this example) to small and program is a national resource that can contribute large companies on challenging activities to help to the global competitiveness of the precision industries help themselves by developing new manufacturing industry. Thus, DOE is funding products and processes. this activity under a new name. Called the Ultraprecision Manufacturing Technology Center, The Personnel it is one of the Centers for Manufacturing Technology at the Y-12 Plant. The center has a More than 50 people, including a core staff of new and expanded mission. It no longer focuses 18, contributed to the Optics MODIL program only on manufacturing processes for optical over the past five years. The program's well systems. Instead, its resources are being applied to rounded staff of designers, engineers, scientists, the many industries that need ultraprecision physicists, technicians, and administrative support components, such as the medical, environmental, represented all three sites in Oak Ridge. People and electronics enterprises. often ask the staff, "How did you pull it off?" The Ultraprecision Manufacturing Technology There is no one-word answer to this question. Center is now a designated DOE user facility; it Effective leadership, a proactive sponsor, a highly provides a convenient mechanism for visiting motivated staff that was willing to go the extra researchers to use our state-of-the-art equipment. mile to get things done, and an atmosphere of The transition from one agency sponsor to another

Number Three, 1994 31 UL TRAPRECISION MANUFACTURING TECHNOLOGIES FOR OPTICS

illustrates the government's goal of using suppliers of single-point diamond tools. Many of resources most effectively to benefit taxpayers. these U.S. firms are small businesses that are The center staff is excited about new competing with large, well-established foreign opportunities as its horizons move beyond optics companies that have large resources. Because the for defense applications. The center has been shape of the tool is instrumental in forming working with an environmental firm in Knoxville, extremely accurate contoured parts, the tool Tennessee, that manufactures air quality monitors. companies needed a method of measuring the This small business is losing market share to a tool's roundness within a few millionths of an German competitor. Discussions between inch. They also needed a map showing the size A CRADA technical staffs revealed areas for improvement in and location of roundness errors. was recently the design and manufacture of their product. By The problem was that users of the tool had to negotiated to making a contact through the National Machine do in-house inspections to determine if the tool Tool Partnership, a multiagency-sponsored met their needs. The users had to machine and help this assistance program, this firm got an introductory inspect a part; if it failed to measure up, it would small feel for our capabilities. Next, the company came eventually be scrapped. Unless this situation to the center as a "user" to conduct hands-on changed, the U.S. tool suppliers were at risk of business beat research. Finally, a CRADA was recently losing customers. out foreign negotiated to bring this effort to closure and help We developed a user-friendly technique with competition! this small business beat out foreign competition! an easy-to-read output that verifies the accuracy Another demonstration of our commitment to of the diamond tool edge for the tool industry. supporting domestic industry involves an effort Now, the diamond tool supplier can provide data with a contact lens manufacturer. The to the tool user that verify the tool's accuracy. characterization of contact lenses presents many Our technique saves the user time and money challenges, not only because the product is flimsy because in-house acceptance testing is no longer and slippery but also because its demand is high. needed. Each lens must be measured for performance (will By working with a number of private it correct a wearer's vision as intended?) and companies, we have been able to pinpoint areas appearance (does the lens have scratches?). A for improvement in the design and manufacture cooperative effort investigated methods of of their product. This capability, combined with automating the contact lens inspection process. providing companies access to the center's The Ultraprecision Manufacturing Technology research facilities, helps to create partnerships Center staff has also worked closely with U.S. that benefit business, the center, and the nation. !!!::!!

32 Oak Ridge National Laboratory REVIEW We have helped private companzes zmprove their design and manufacture ofproducts .

Number Three, 1994 33

ore and more Americans are cruising the The light-transmitting ability of the barium information highway. They are titanate f!lms has been verified in tests at ORNL, M accessing the Internet and sending Wright-Patterson Research and Development electronic mail throughout the world. They are Center in Ohio, Hughes Aircraft Corporation in looking forward to the day when they can tune in to California, and AT&T in New Jersey. In these hundreds of cable television channels. Eventually, tests a laser is used to transmit a !-millimeter they will use their telephones and television sets to wide beam of light through the waveguide ORNL call up their favorite movies to watch immediately medium, but ultimately a !-micrometer-wide or store for later viewing. They will be able to channel, or optical path, will be used. researchers receive airline schedules, news, and catalog Even with today's technology, an optical fiber have shopping information when they want them. uses less than 1% of its theoretical capacity, or To speed communication and retrieval of bandwidth, for carrying information. In other developed a information as the number of users increases, the words, the information highway has room for new class of evolving information highway must be constructed to expand its high-speed data traffic. thin-film A possible solution to this capacity waveguides. problem is a promising new material developed by researchers at Oak Ridge National Laboratory. The material is being studied for possible use in optical switches for networks of glass, or optical, fibers that are as fine as human hair. Preliminary results indicate that the ORNL material could pave the way for much greater use of the emerging information highway. Using a technique called molecular beam epitaxy (MBE), Rodney McKee and Fred Walker, cientists in ORNL' s Metals and Ceramic (M&C) Division, have A light beam from a laser at left (shown on front cover) is bent developed an optically clear ceramic by a prism (darkened triangular solid in foreground) before film for transmitting waves of light. entering and passing through a thin-film waveguide, whose This "waveguide" material consists borders are also illuminated by laser light. The light-conducting of barium titanate, deposited one material, made of barium titanate deposited on magnesium atom-layer at a time on a crystal of oxide, is of interest to industry and the government because of magnesium oxide. They have also its potential for improving optical switches and other devices. shown that the waveguide material can be deposited on silicon. Their goal is to considerably more high-speed data traffic if the develop an optical switch consisting of silicon on appropriate technology is developed. which is deposited magnesium oxide, the barium "Switches using this type of waveguide could titanate waveguide, and appropriately configured increase the amount of information carried by electrodes. fiber-optic cables by 100 times," McKee says.

Rodney McKee (standing) and Fred Walker view a video camera image of a laser beam passing through a waveguide material they developed. In front of the monitor screen are a laser, laser beam, waveguide sample, and camera.

Number Three, 1994 35 ORNL'S THIN-FILM WAVEGUIDE AND THE INFORMATION HIGHWAY

"Since the advent of lasers in the early sixties, titanate. ORNL's ability to grow barium titanate scientists have dreamed of replacing electrical as a single-crystal t1rin film one layer of atoms at circuits with all-optical circuitry or integrated a time can produce a well-ordered and nearly electro-optical device in silicon-based technology. defect-free material with electro-optical With these materials, our dreams may oon properties potentially 35 times better than tho e become reality." of lithium niobate. In other words, a barium Since the Over the next few decades, copper wire for titanate switch could be 35 times smaller or use advent of telecommunications will be replaced with optical 35 times less electricity than a lithium niobate fibers made of glass. Glass is much cheaper and switch. lasers in the more common than copper. Even more important, Each piece of digital information traveling on early sixties, glass fiber can carry 250,000 times as much the information highway is called a binary digit, scientists information in the form of light from lasers a does or bit. A bit is either a 1 or 0; a combination of 8 a standard copper telephone wire conducting bits, which can define a letter or number, is have electrical signals. The reason: glass conducts light called a byte. Bit can be transmitted into a glass dreamed of signals of much higher frequency-number of or copper-wire cable by a switch. lf a switch is waves per second-than copper can for electrical on, it lets through a high-intensity light or replacing signals. The higher the frequency, the more electrical signal that represents a 1; if the switch electrical information can be packed into light signals. is off, it passes a low-intensity signal that circuits with The ORNL achievement will contribute to represents a 0. Each combination of high recent developments that have enabled the intensity and low-intensity signals represents a all-optical transmi ion of increa ed amounts of information word, number, or other data. circuitry. by light. They include miniature lasers on silicon Today digital pulses, or bits, of information are chips (laser diodes), improved optical fibers that sent down optical fiber by gating-turning on carry light longer distances, and optical switches, and off-laser diodes, tiny sources of light of which convert electrical signals to light signals. different frequencies (representing different Such technology must economically produce telephone conversations, for example). More key components of the infom1ation highway. It advanced technology uses lithium niobate to gate should use a single fabrication process to light from a continuous laser source. Although incorporate laser diodes, microcircuits, electrodes, lithium niobate switches are faster than switched and optical switches on a silicon chip, or sub trate lasers, the data transmission rate is still limited to (the physical structure that provide electrical and a frequency level of 1 to 10 gigahertz. With mechanical support for microelectronic barium titanate (which has a larger "bandwidth"), components). Silicon is the choice support the data transrnis ion rate can reach 1000 structure for these components because of its gigahertz, permitting about 100 times more purity, crystal perfection, and associated electronic information to be transmitted. and physical properties. In optical guided wave devices such as optical switches, electric fields are pulsed to switch the Optical Switches light signals on and off in the waveguides, which have a much faster response than the laser Although a number of material systems are diodes. The reverse is also true: Light signals to being studied, the waveguide material chiefly in waveguides on silicon chips are rapidly commercial use today for optical switches is converted to electrical signals. lithium niobate. However, this material is damaged In an optical switch using barium titanate, light after repeated passage of laser light, making the is split into two paths. An alternating electric laser signal too weak for the switch to work. field is applied to the electrodes of one of the Another drawback is that no way has been fo und to beam paths. When the field is on, it changes the integrate this material with other components on phase of the light signal in one path relative to silicon. Currently, lithium niobate cannot be the other path; in other word , the field causes deposited as a thin film on silicon as can barium the waveguide material to shift the positions of

36 Oak Ridge National Laboratory REVIEW the crests and troughs of the light waves passing through. When the two beams of light recombine, they mutually interfere, reducing the intensity as the light exits. The light When the field is off, the split was light beams recombine as a efficiently signal with the same intensity they had entering the switch. conducted The resulting combinations of through the increases and decreases in light intensity serve as rapid waveguide "on-off' switches, greatly with increasing the amount of practically information transmitted. McKee and Walker are no loss of developing a prototype intensity. optical switch using barium Drawing of an optical switch for use in fiber-optic telecommunications. titanate as a planar waveguide with aluminum electrodes attached to do the on-and-off switching. The ORNL researchers were the first to grow They are also working with AT&T on an optical high-performance thin-film ferroelectric oxides switch in which narrow channels for light about with low losses of light. They use MBE to build the size of the wavelength of visible light are each film layer by layer, creating a desired etched into the ORNL waveguide material. It is ordered structure to enable the transmission of these channel waveguides that allow practical light. To produce the optical waveguide on optical circuits to be integrated into the material. silicon, the researchers first grow a transition This new class of waveguide structures and their oxide a few atom layers thick on a single-crystal potential for integration into silicon-based silicon substrate. This transition oxide is a critical technology, if exploited in a timely manner, could component that provides a structural match to advance communications technologies, benefiting magnesium oxide (MgO). Magnesium oxide was consumers, industry, and the federal government. chosen because of its optical properties, crystal structure, and stability. As an isolation layer, it Formation of separates the waveguide from the substrate, preventing the silicon from absorbing and Thin Films dissipating light passing through. Also, its atoms Since 1989 McKee and Walker have been using can be lined up with those of silicon, the unique the demanding technology of MBE to form these transition oxide, and barium titanate, permitting light-transmitting ceramic thin films on an optical properly oriented growth of these materials. isolation layer of magnesium oxide on silicon. MgO is an alkaline earth oxide like barium Although their research and approaches to this oxide, calcium oxide, and strontium oxide. The materials development problem have been at a ORNL researchers thought that atoms of any of very fundamental level, they have developed these materials could be lined up with those of practical technology while making scientific silicon and barium titanate, the waveguide advances. As a result of their work, they have material. The researchers used barium oxide received one patent, applied for three more, and (BaO) first as an isolation layer, but they found published a series of journal articles in Applied that it reacted with water vapor during the Physics Letters and Physical Review Letters. deposition process, forming barium hydroxide. In

Number Three, 1994 37

McKee (foreground) and Fred Walker optim ize the process whereby molecular-beam epitaxy techniques are used to deposit a light-conducting barium titanate film on a layer of magnesium oxide. The result of this process is a thin-fi lm waveguide.

their experiments they found that MgO worked much better as an isolation layer. Barium titanate is both a perovskite (a mineral with a roughly cubic crystal structure like that of silicon and MgO) and a ferroelectric (a material in MgO which the positive and negative ions move apart, setting up electric fields within the crystal). The A thi n film of barium titanate has been interaction between the internal electric field and deposited on magnesium oxide to make a waveguide materi al that can be integ rated the applied external field controls the material's with silicon. ability to influence the information content in a guided light wave. The ORNL group formed a transparent film of alternate one-atom-layer-thick deposits of

) titanium oxide (Ti02 and BaO. The researchers

aligned the atoms of Ti02 with respect to the atoms in the MgO layer. Next they added a BaO layer in proper alignment with the Ti0 • They 2 repeated the process many times, fabricating a barium titanate film thick enough to transmit a thin laser light beam. The light was efficiently conducted through the waveguide with practically no los of intensity. In addition, the researchers showed that the waveguide film and isolation layer could be deposited on a silicon substrate. They are now working on growing these films on larger-diameter silicon to reduce the cost of each This transm ission electron micrograph shows optical switch and make the manufacturing that the interface between the waveguide's process more economical. barium titanate and magnesium oxide lattices In making a BaTi03 film, why is a Ti02 layer is chemically and stru ctu rally sharp. rather than a BaO layer deposited first on the MgO layer? The reason, McKee says, is that the arrangement of the atoms makes for a good electrostatic fit, or proper "ionic coordination," between the layers. The positively charged titanium ions in the waveguide layer interfacing with the isolation layer are attracted electrostatically to the negatively charged oxygen ions in the MgO layer, and the positively charged magnesium ions are attracted electrostatically to the negative oxygen ions in the Ti0 layer. 2 Depositing a BaO layer on the MgO layer first does not work; when placed near each other, the atoms in both layers (barium atoms on magnesium atoms, and oxygen atoms on oxygen atoms) will This scanning electron micrograph clearly repel each other because of like charges. shows the interface between barium titanate Deposition of the Ti0 layer, which is formed by and magnesium oxide in a fracture cross 2 section. The barium titanate fi lm is 0.6 vaporizing a titanium sample in low-pressure micrometers thick. oxygen, is followed by deposition of a BaO layer,

Number Three, 1994 39 ORNL'S THIN-FILM WAVEGUIDE AND THE INFORMATION HIGHWAY

familiar waveguide is the optical fiber. Light i guided along an optical fiber by undergoing total internal reflection at the interface between the air and the glass fiber. Glass fibers and other transparent materials can form waveguides if their index of refraction is significantly higher than that of the surrounding Our tests medium. In such a case, light trying to escape the show that waveguide into the medium will be bent back, or internally reflected, into the waveguide. The best magnesium waveguides minimize optical losses. oxide is an Because of the importance of the refractive effective index in keeping the light inside the waveguide, the ORNL researchers in collaboration with David isolation Zelmon of Wright-Patterson Research and layer. Development Center in Ohio developed a four Ti02 tru layer waveguide structure. The first three layers are silicon, MgO, and BaTi0 . The fourth layer, interface 3 air, acts as an isolation layer like MgO. This drawing shows the attractive electrostatic "To make a ferroelectric waveguide," says interaction between positively charged titanium ions McKee, "we could not simply deposit barium in the waveguide's titanium oxide layer and the titanate on silicon to make a three-layer negatively charged oxygen ions in the magnesium waveguide (with air as the top layer) becau e oxide layer below and between the positively silicon's index of refraction is higher than that of charged magnesium ions and the negative oxygen barium titanate. Because silicon will absorb and ions in the titanium oxide layer. Deposition of a dissipate light, we had to put down an optical barium oxide layer on the magnesium oxide layer first (instead of the titanium oxide layer) does not isolation layer between the substrate and guiding work. When placed near each other, the atoms in layer. We chose magnesium oxide because its both layers (barium atoms on magnesium atoms, index of refraction is lower than that of barium and oxygen atoms on oxygen atoms), will repel titanate and because its atoms can be lined up with each other because of like charges. those of silicon and barium titanate, making a good epitaxial film. Our tests show that then a Ti0 layer, then a BaO layer, and so on to magnesium oxide is an effective isolation layer." 2 . The index of refraction for BaTi0 is 2.4, form BaTi03 3 "This technique is called planar tacking," significantly higher than the refractive indices for McKee says, "because layers are stacked to form the two isolation layers. For MgO it is 1.8, and for a compound of both a desired composition and air it is 1. The differences keep the light traveling

structure. We hope to improve the properties of in the BaTi03 layer. existing compounds and synthesize new materials this way." Molecular Beam Epitaxy Using MBE techniques to make the thin films, Layered Structure the researchers heat a magnesium oxide crystal An obvious example of a waveguide is a mirror grown by Lynn Boatner of ORNL's Solid State placed upon a mirror so that only the silver Division. The crystal's MgO molecules vaporize backing is visible. If light is passed between the in a chamber containing a silicon substrate in two mirrors, it will be reflected between them as it ultrahigh vacuum. Because the chamber is kept at moves from one end to the other. The most extremely low air pressure, the vaporized MgO

40 Oak Ridge National Laboratory REVIEW molecules reach the silicon without encountering reflection high-energy electron diffraction many air molecules. Titanium and barium are (RHEED). RHEED directs a high-energy vaporized and reacted with oxygen to make electron beam at the sample at a very low angle alternating layers of titanium oxide and barium (1 to 2°) to obtain detailed surface information. If oxide, which are aligned to form a barium titanate the monitoring technique indicates poor atomic waveguide film. alignment and crystalline imperfections, then the "Our group "To produce a thin film with good optical researchers change temperatures, pressures, and quality," McKee explains, "we maintain stringent other parameters to improve film quality. atORNLhas synthesis and processing requirements at the near "When RHEED electrons trike the atoms of achieved the interface regions. We have to regulate the arrival the film," says McKee, "they are deflected to a rate of the oxygen, the temperature of the metal phosphor screen, and the points of light there first being vaporized, and the temperature of the show the arrangement of the atoms in a demonstration substrate. Source-shuttering MBE techniques give crystalline pattern and indicate whether the film of optical us control at the atomistic level of materials is growing across the substrate surface in an development." orderly way. Distortions in the electron pattern clarity in thin To make defect-free, crystalline films in which can indicate defects in the crystalline structure, film barium all the atom are epitaxially aligned, the ORNL telling us that we must fine-tune the film-forming researchers monitor film formation using process." titanate."

Thin-Film Waveguides and Optical Computers

Improved waveguides are needed in the world of data processing. where faster is better. To speed up calculations. silicon-based optical computers are envisioned in which optical waveguides and optical interconnects are incorporated to reliably transmit light signals. Currently, there is a significant technological barrier to efficent transmission and attempts at manipulation of large data arrays. Today·s electronic switching technology, which converts light to electrons and back to light again, cannot convey all the information crammed into the initial light signal at the highest possible speed. Viewers of teleconferences are aware of this problem. Today. a person in a tele conferencing image appears in black and white and makes jerky hand motions. This is a bandwidth problem; even a slow optical switch can switch a very wide bandwidth optical signal more effectively. Integrated optical guided wave devices and optical interconnects of the future will render teleconference images that are in color and show continuous movements. Besides its wider bandwidth, light offers two other advantages over electrons for data processing. The way an optical signal can be processed using optical waveguides and interconnects could greatly increase the speed of future computers. For both serial processing and parallel processing of data, light pulses-or bits of information-in an optical signal can be generated at rates that are at least 1000 times faster than electronic pulse rates . This advantage should make possible ultrafast serial data processing that cannot be achieved electronically. Moreover, a digitized image that might contain 108 bits/cm 2 can be transmitted as a multiple-wavelength optical signal in an optical computer, and parallel processing can be used to speed up the image manipulation for display. In a world where faster is better, thin-film waveguides like those being developed at ORNL may be the key to tomorrow's computers and data-handling devices.

Number Three, 1994 41 ORNL'S THIN-FILM WAVEGUIDE AND THE INFORMATION HIGHWAY

Evaluating the Waveguide A variety of ORNL resources have been called upon to analyze the material and optical properties of the thin-ftlm waveguide. Kathi Alexander, a materials researcher in the M&C Division, has been studying the waveguide's crystalline lattice structure using the Hitachi field-ernis ion gun transmission electron microscope at ORNL's High Temperature Materials Laboratory. She hopes to determine the structure of the magnesium oxide-barium In the ferroelectric state represented by c/a, the titanate interface that provides optical clarity. internal electric field polarization is parallel to Scanning electron microscope images produced the c direction. The optical polarization (OP) is in the M&C, Solid State, and Health Science at 45° to both the internal and applied electric (E) fields. In the fall of Research divisions have shown that the thin film waveguide's optical properties are superior 1994, McKee to the bulk materials now used. and Walker "Our group at ORNL," says McKee, "has achieved the first demonstration of optical demonstrated clarity in thin-film barium titanate. that this new Characterization of our waveguides produced by growing nearly perfect thin films of barium class of The barium titanate and magnesium oxide titanate on magnesium oxide has shown that composite thin films are deposited on silicon. waveguides their ability to channel light with little loss in The MgO provides optical isolation, confining intensity is as good or better than that of bulk could be the light to the BaTi03 1ayer. Electrodes at the titanium-drifted lithium niobate waveguides. side apply an electric field at 90° to the integrated This materials synthesis achievement points the internal electric field, and the best possible with silicon. way towards development of a whole new class electro-optic properties are obtained in the BaTi0 waveguide from its deposition on of waveguides-thin-film perovskites on 3 alkaline earth oxides. silicon. "This ORNL development is important for several reasons. First, the bandwidth achievable for these thin-film waveguides is about 100 times that of a bulk ferroelectric like lithium niobate. Second, the electro-optic coefficient is 35 times larger than that of lithium niobate and 300 times larger than that of gallium arsenide. Such a high-performance characteristic would enable fabrication of smaller, faster, and more efficient devices. Third, we have shown that, unlike lithium niobate, our barium titanate magnesium oxide composite waveguide can be deposited on silicon and that, fortunately, the ORNL researchers recently demonstrated that problems we anticipated in integrating our light can be channeled through barium titanate waveguide material with silicon to make and magnesium oxide composite thin films that practical devices can be avoided." have been deposited on silicon, as shown in this video image.

42 Oak Ridge National Laboratory REVIEW The Silicon Solution McKee explains the technical basis for his concern about integrating the waveguide When efforts were initiated to try integrating material with silicon. "The electro-optic these waveguide structures with silicon, McKee, properties of barium titanate are directionally Walker, and others were concerned about the dependent," he says. "So we were concerned structural change that occurs when the BaTi0 - 3 about the spontaneous polarization-the MgO films cool after being deposited on silicon. collective displacement of charged ions-and the The question was this: although the waveguide domain structure-regions in which positive and material is chemically compatible with silicon, is negative ions separate, setting up electric it structurally compatible after deposition as a fields-in the crystalline film of barium titanate. "Nature has film? "We knew that barium titanate's spontaneous been kind to In the fall of 1994, McKee and Walker polarization and domain structure could couple demonstrated that this new class of waveguides to thermal strain in the silicon substrate, making us. Wefound could be integrated with silicon. McKee reported it difficult to achieve the best possible electro that a this success at the Materials Research Society optic response. But Nature has been kind to us. potentially annual meeting in November 1994. He also We found that a unique and potentially reported their finding that the structural change advantageous domain structure can be obtained advantageous that caused concern actually favors the for our barium titanate-magnesium oxide domain fabrication of a silicon-based waveguide! waveguides if we grow them on silicon." structure can When deposited on silicon, the BaTi03 film is For their silicon demonstration, McKee and in its cubic phase. As the BaTi0 film and silicon 3 Walker received support from ORNL's be obtained substrate cool, the film tries to shrink but stays in Laboratory Director's R&D Fund. They are for our place on the substrate. As a result, the using this funding to develop methods of microstructure of BaTi03 is stretched-from a depositing waveguide material on silicon at a waveguides cubic to a tetragonal configuration. In other lower temperature-a range of 300 to 500°C ifwe grow words, if the structural change could be greatly instead of 500 to 800°C. A lower temperature i magnified, you would see stacks and rows of required to make silicon chips that integrate them on cubic boxes turned into stacks and rows of microcircuits, laser diodes, and optical switches silicon." upright milk cartons. using a single economical fabrication process. To relieve this tension, the molecules shift To accomplish this goal, McKee says, 90°C or "lie down," thereby aligning their long adjustments must be made in the oxygen axis with the surface of the plane. Viewed another pressure of the film-growth chamber and the way, the "milk cartons" are laid down on their arrival rate and time for oxygen in contact with sides. the vaporized metals of magnesium, barium, and "This transformation is critical to waveguide titanium. development," McKee says. "The new alignment McKee and Walker will continue work with makes it possible to obtain barium titanate' s collaborators to achieve the correct thicknesses optimum electro-optic coefficient. It allows us to of the light-guiding and isolation layers for the easily orient the applied electric field with the four-layered waveguide structure, to develop crystal's internal ferroelectric field and optical better optical switches, and to make possible the polarization of the traveling light wave signal economical manufacture of silicon chips that that is, the orientation of the bght wave integrate optical switches with laser diodes and vibrations. Thus, this favorable structural change microcircuits. These developments could help will enable us to integrate our waveguide material the United States win the global race to find with silicon and to control the waveguide ways to significantly speed up communications structure so that practical silicon-based optical and computations (see sidebar on p. 41), greatly guided wave devices can be built." improving the information superhighway.

Number Three, 1994 43

he American public is becoming Biological events that provide information increasingly aware that the natural about the environment include more, however, T environment is fragile. The news media than increases and decreases in animal and plant have reported on many instances of species. A variety of pollutants resulting from environmental changes affecting animal life, human activities can interfere with the normal A variety of often as a result of pollutants from human functioning of an organism, making it less able to activities. Recent reports have focused on grow normally or reproduce successfully in its pollutants environment. Short of death, some of the more resulting • Deaths and population declines of birds and common but serious effects of environmental fish because of the large oil spill in Prince from human William Sound in Alaska; activities can interfere • Deaths of porpoises and whales along the east coast of the United States, possibly as a result with the of pollutants and disease; normal

• Fish contaminated with polychlorinated functioning biphenyls (PCBs) in Fort Loudoun, Tellico, of an Watts Bar, and other East Tennessee organism. reservoirs;

• Contamination of the Pigeon River in Tennessee and North Carolina by dioxin and other pollutants that may cause cancer and reproductive disorders.

These events may be omens that other forms of life, including people, could become threatened if environmental conditions continue to worsen. But how much worse must conditions be before wildlife and human life are in danger? Or are they in danger already? Clearly, better methods are needed to predict the probability of future environmental and health problems based on present evidence. Such information could Marshall Adams takes a blood sample from a fish guide environmental regulators and decision collected from Watts Bar Reservoir for bioindicator makers in taking actions in time to minimize studies. damage to the environment and human health. Biological events, such as increases in the stressors on aquatic organisms are changes in populations of pollution-sensitive species in a behavior, growth, and reproduction. These river or the return of a fish species to a once changes in individual organisms, known as polluted stream, can also indicate recovery of an biological indicators (or bioindicators, for short), ecosystem. Such information helps scientists can eventually result in large-scale changes in determine the extent to which remediation of a biological communities and even ecological contaminated waterway has been successful. systems.

Analysis of fish blood could in dicate the presence of environmental threats to wild life and people.

Number Three, 1994 45 EARLY SIGNS OF ENVIRONMENTAL DAMAGE AND RECOVERY

studied bioindicators in the Pigeon River and in estuaries in South Carolina, all of which are polluted by pulp and paper mill effluents. We have looked at ecological effects in reservoirs in South Carolina and Georgia, which are contaminated by high levels of PCBs, and in natural lakes at Cape Cod, Massachusetts, which receive underground plumes of contaminants Rio indicators from a nearby military are useful facility. because they Early Warnings of are telltale ORNL researchers collect fish samples from East Fork Poplar Creek in signs of Oak Ridge. Environmental Damage impending Researchers in the Environmental Sciences environmental Division (ESD) at Oak Ridge National Bioindicators are useful because they are telltale igns of impending environmental problems. Laboratory are using wildlife species, such as fish and waterfowl, as bioindicators of ecosystem problems. Early effects of pollution initially health. Our goal is to develop and improve our occur at the lower levels of biological capabilities for detecting and predicting the organization. Changes in genes, cells, tissues, effects of environmental stress on key, or body chemical processes, and basic body "sentinel," ecological species. This information functions appear before more severe disturbances could lead to appropriate actions that prevent occur in populations and ecosystems. These undesirable and irreversible effects in ecological biochemical and molecular effects can be systems such as streams, rivers, and lakes. detected as changes in enzyme levels, in tructure At ORNL Mark Greeley, Rhonda Epler, Kai of cell membranes, and in genetic material, or Lin Lee, Lee Shugart, and I are involved in DNA. Change at these subcellular levels induce research to identify biomolecular, biochemical, a series of tructural and functional responses at physiological, and other organism-level the next level of biological organization. For respon es of aquatic organisms to environmental example, complex processes such as hormonal stressors such as contaminants. ORNL regulation, metabolism, and immune system researchers have developed bioindicators of responses can be impaired. These effects may pollutant stre s and used these indicators to eventually alter the organism's ability to grow, assess ecological health in creeks, reservoirs, reproduce, or even survive. All these mea urable rivers, and marine systems. We have applied this changes serve a bioindicators of pollutant stress. approach to determining biological effects of They provide early warnings of environmental contaminants in various waterways on or near damage. the Oak Ridge Reservation: East Fork Poplar Ultimately, irreversible and detrimental effects Creek, White Oak Creek, Mitchell Branch, the may be observed at the population and Clinch River, and Watts Bar Reservoir. We have community level, adversely affecting the health

46 Oak Ridge National Laboratory REVIEW of the entire ecosystem. Low Dramatic examples of these ecological effects are mass deaths of relevance I whales and porpoises along I the eastern U.S. and Gulf of Biochemical I Mexico coasts, wholesale shifts in aquatic species and community structure in the Detox enzymes Great Lakes of the United Bioindicators States, and biologically dead Physiological Immunological of pollutant rivers and reservoirs in Russia. These examples attest stress range Histopathology to the highly destructive from organ effects of pollutants on the Short-term Long-term damage environment. response response Condition responses to Examples of indices bioenergetics increased Bioindicators Reproductive mortality competence One way a physician can rates of determine the cause of a patient's health problems is to organisms. analyze a blood sample. The health of a fish can be Population and determined in a similar way. community Analysis of blood from a fish High can indicate problems in ecological organ function-a relevance bioindicator. For example, the Detectible changes in genes, cells, and tissues of an organism may later presence of specific types of be the first signal of more severe disturbances in its population and enzymes (tranaminases) in community. fish blood can indicate liver impairment. Just as alcohol can cause liver high levels of heavy metals and to highly acidified damage, or cirrhosis, in humans, PCBs and surface waters. In the Great Smoky Mountains polycyclic aromatic hydrocarbons in the aquatic acid rain can drastically raise the acidity level of environment can inflict liver damage in fish, mountain streams, periodically killing trout in leading to more serious problems. hatcheries. Elevated levels of another bioindicator, urea As these examples show, bioindicators of nitrogen, in fish blood reflect abnormalities in gill pollutant stress range from organ damage function, or respiratory problems. When responses to increased mortality rates of functioning normally, fish gills as well as kidneys organisms. excrete nitrogen-bearing waste products from the body. Fish gills can be damaged by heavy Uses for metals-mercury and aluminum-and acidified Bioindicators water. We have found evidence of such effects in fish from the Great South Fork Recreational Area The bioindicator approach is not the only in Tennessee and Kentucky. In this area, drainage method for monitoring possible ecological effects from abandoned coal mines contributes both to of pollutants. One traditional method is direct

Number Three, 1994 47 Habitat Temperature

Contaminants

Integrated responses

Growth Reproductive success Bioindicators can provide early '\../ Population warning response signals of potential The health of an animal reflects the combined effects of environmental stresses acting on it. Studying an human animals' reproductive success and other factors enables researchers to predict the population response health and assess the nature and extent of environmental degradation. effects. measurement of chemical pollutants in streams or stre es, such as contaminants, unfavorable in the organisms themselves. Another is the temperature, suspended sediments, insufficient laboratory toxicity test in which the toxicity of a oxygen, and food shortages. Largemouth bass and pollutant is determined by the death rate of striped bass-important sport fish commonly found exposed organisms. Compared to the bioindicator in reservoirs in East Tennes ee reservoirs-are approach, these methods often provide only limited particularly good integrators of environmental information. stress because they are at the top of the aquatic Bioindicators offer several types of rather unique food chain. Signs of impaired health in fish enable information not available from other methods: (1) scientists to as e s the nature and extent of early warning of environmental damage; (2) the environmental degradation. integrated effect of a variety of environmental Bioindicators can be used to establish cause-and stresses on the health of an organism and the effect relationships between different levels of population, community, and ecosystem; (3) response to pollutants in individual organisms and relationships between the individual responses of for the entire population. For example, if a diseased exposed organisms to pollution and the effects at fish is found in a stream, it should be possible to the population level; (4) early warning of potential determine not only the cause of the disease but also harm to human health based on the responses of the potential consequences of that disease for the wildlife to pollution; and (5) the effectiveness of individual fish and for the population. If the disease remediation efforts in decontaminating waterways. kills young fish and impairs reproduction in older The physiological condition of an animal reflects fish, then the population may decline or even the combined effects of all its environmental disappear over time.

48 Oak Ridge National Laboratory REVIEW When sunfish from the Pigeon River were examined, we found problems

The Champion Plant in Canton, North Carolina, is a paper and pulp mill that has discharged dioxins and with their other pollutants to the Pigeon River for many years. endocrine, reproductive, Bioindicators and People downstream of the mill expressed concerns and Human Health about its health effects, such as increased cancer rates, and even filed a lawsuit, which was metabolic For many years, coal miners would place a eventually settled out of court. systems. canary into a newly opened part of the mine to When we examined sunfish from the Pigeon test the toxkity level of gases. If the canary died, River, we found problems with their endocrine, the miners knew it was too dangerous to work; if reproductive, and metabolic systems. We detected the canary survived, they continued their work. altered hormone levels, metabolic and nutritional The fate of the canary served as a bioindicator of imbalances, and changes in the normal population pollutant toxicity that could threaten human and community dynamics. We also observed DNA health and possibly cause death. damage and cancerous lesions in these fish. Such We have found that bioindicators in the effects were attributed to chemicals released from environment can al o provide early warning the mill. ignals of potential human health effects. Several In addition, we found that people in the area years ago, we were asked by the Environmental could have been exposed to contaminants not only Protection Agency to study the health of fish in by eating fish but also by using water from the the Pigeon River. This river was contaminated Pigeon River to irrigate crops and water livestock. with chlorine-containing compounds called Thus, some of their sources of food may be dioxins and other pollutants, primarily from a contaminated with dioxins. nearby paper and pulp mill-the Champion Plant Is there a link between impaired fish health and in Canton, North Carolina. Dioxins are produced a potential threat to human health? Recent studies when elemental chlorine is used to bleach paper. show that dioxin and other environmental

Number Three, 1994 49 EARLY SIGNS OF ENVIRONMENTAL DAMAGE AND RECOVERY

Contaminant input

We found Determine fate and effects of evidence of ecosystem altered sexual development in fish from the Pigeon Identify relevant Identify common exposure pathways biological receptors River. • irrigation • endocrine • ingestion • reproductive •livestock • genetic • fish

Implications for human health

In the case of the contaminated Pigeon River, humans are exposed to dioxin and other paper mill contaminants in several ways.

chemicals can disrupt the hormonal system by of all cancers in women. Thus, the recent ri e in mimicking or inhibiting estrogens in organisms. environmental chemicals, including estrogenlike Estrogens and other hormone are chemical compounds, bas increased exposure of body messengers that regulate various processes in the tissues to estrogen, possibly accounting for the body. Hormones act on parts of the body by 1% annual increase in U.S. breast cancer deaths sending chemical signals through receptors on or since the 1940s. inside cells. This action can be blocked by We found evidence of altered sexual chemicals that mimic a hormone and attach to its development-possible sex changes, impaired receptors. Because hormones regulate growth and gonad development, and reduced steroid hormone reproduction, it is believed that hormone concentrations-in fish taken from the upper and disrupting chemicals could interfere with these most contarninated section of the Pigeon River. processes, possibly leading to reproductive and Interestingly, breast cancer incidences are higher developmental problems in humans. in the two counties downstream of the paper mill Estrogens are known to play critical roles in the than in surrounding counties. There is only about development of breast cancer. ln fact, hormones a 1 in 500 probability that the observed are believed to be indirectly responsible for 40% incidences of breast cancer in these two counties

50 Oak Ridge National Laboratory REVIEW

indicators for human health. We are using data supplied by Gilman to write a paper on this subject. In the Great Lakes area in the late 1980s, Theodora Colborn, a zoologist with the World Wildlife Fund, discovered problems with the offspring of 16 predator :tors species, including fish, birds, reptiles, and mammals. Many of the young failed to survive to d to adulthood or to reproduce. These animals experienced these problems apparently because their parents ate fish from the Great md Lakes, which were contaminated with hormone-disrupting chemicals. These wildlife species This field laboratory on the Pigeon River was used for on-site ieSS provide one of the first models fo r processing of fi sh samples. ·az the transfer of hormone-disrupting chemicals from one generation to n the next. Such responses in wildlife can provide models for predicting responses of humans to the same on. environmental pollutants. However, it is difficult to prove that declines in wildlife populations are attributable to certain suspect chemicals. It is even more difficult to prove that these chemicals are affecting human fertility in the United States. These difficulties can be addressed only through multidisciplinary research linking ecological, wildlife, human, and laboratory animal research and by ESD researchers Don Harris, Marshall Adams, and Scott Niemela building bridges among the collect a fish sample for bioindicator studies using an human, veterinary, and electroshocking boat on Watts Bar Reservoir. environmental health sciences. are due to random chance alone. This example suggests that bioindicators could provide a Environmental reliable early warning that human health may be Restoration potentially endangered by increasing levels of environmental pollution. Since 1942 research and production activities on In a project coordinated with Andy Gilman of the Oak Ridge Reservation have resulted in the Great Lakes Health Effects Program, we are occasional spills or discharges of hazardous examining the implications of ecosystem health materials, including radioactive cesium, PCBs, and

Oak Ridge National Laboratory REVIEW mercury into various waterways. Recent environmental laws and regulations such as the Clean Water Act; the Resource Conservation and Recovery Act, and the Comprehensive Environmental Response, Compensation, and Liability Act impo e limits on releases of these materials and require that these materials be properly treated, recovered, and isolated from the environment. They also require cleaning up waterways and land contaminated by discharges of hazardous materials. In the Biological Monitoring The ellipsoids represent the integrated health of fish populations at and Abatement Program various sites in East Fork Poplar Creek (darker ellipsoids) and in directed by Jim Loar of ESD, three reference sites (lighter ellipsoids) . Intersecting dark and light bioindicators are being used to ellipsoids that indicate the health status of the sites are statistically evaluate the short-term and similar. long-term effectiveness of remedial actions on aquatic systems receiving herons and ducks) living in or near these discharges from ORNL, the Oak Ridge Y -12 waterways. ln addition, the levels of Plant, and the Oak Ridge K-25 Site. These contaminants-PCBs, heavy metals, and remedial actions are being taken to comply with radionuclides-are being measured in animals environmental regulations. (by ESD's Marshall Adams and Mark Biological indicator studies on East Fork Poplar Bevelhirner), sediments (by ESD's Dan Levine), Creek since 1986 have shown marked and the water (by ESD's Clell Ford) of the Watts improvements in the health of fish populations in Bar system. the stream at several levels of biological An unusual aspect of this project is that both organization. In fact, several pollution-sensitive the bioindicators and contaminant data will be species of fish that have been missing from the used for human health and ecological risk creek for years are now beginning to flourish there assessments (by ESD' Glenn Suter and Larry (see sidebar "East Fork Poplar Creek: Signs of Barnthouse). These assessments will guide Ecological Recovery" on p. 54). regulators in determining the extent of Bioindicators are al o being used to evaluate environmental restoration required in the Clinch both the need for and potential effectiveness of River-Watts Bar system. Additional bioindicator remedial actions on the Oak Ridge Reservation. and contaminant data will be obtained later from The reservation has been a source of pollutants to this system to determine the effectiveness of any off-site waterways-Poplar Creek, the Clinch reservation-wide cleanup. River, and Watts Bar Reservoir. As part of the Bioindicators are an excellent tool for Clinch River Environmental Restoration Project monitoring the health of biological populations, directed by Bob Cook of ESD, we are assessing assessing the potential hazards of environmental the health of important wildlife species, such as pollution to human health, determining if several fish species (largemouth bass, bluegill, industry is complying with regulations, and catfish, and striped bass) and waterfowl (blue evaluating the effectiveness of remedial actions. =

Number Three, 1994 53 EAST FORK PoPLAR CREEK: SIGNS OF EcoLOGICAL RECOVERY

Because of new facilities that remove chlorine and "We are seeing pollutants from wastewater at the Y-12 Plant before it . . is discharged to East Fork Poplar Creek (shown here), an mcrease m the number of fish species in the creek has risen. the number of fish species in East Fork Poplar Creek."

54 ast Fork Poplar Creek is on inhabited upper and lower East Creek provide strong evidence of the road to recovery, Fork Poplar Creek inside the plant. ecological recovery, the stream still Eecologically speaking. Today several pollution-tolerant fish has a way to go before it could be So says Jim Loar, an ecologist in species-striped shiner, blacknose considered a reference creek. "For ORNL' s Environmental Sciences dace, central stoneroller, and example," Loar says, "what is Division who has spearheaded the redbreast sunfish-have returned to missing is the presence of pollution- Biological Monitoring and these waters. sensitive fish species. However, a Abatement Program (BMAP) for the Since 1985, ORNL researchers few individuals of some pollution- Oak Ridge Y-12 Plant. BMAP was Jim Loar and Mike Ryan have sensitive fish species-bigeye chub, established in 1985 so that the Y-12 observed more than a tenfold redline darter, and greenside Plant could receive a National increase in fish abundance in East darter-have been observed in the Pollutant Discharge Elimination Fork Poplar Creek, just below Lake creek for the first time." System permit for releasing effluents Reality at the Y-12 Plant. They have Growing evidence shows that the to East Fork Poplar Creek. observed an increase in the number health of fish populations in the According to polluted creek is

Loar, since 1985 16 ..------, improving. This the Laboratory improvement may be 14 has gathered attributed to several 12 "evidence of "(3~ factors: the recovery 1n g. 10 implementation of stream o 8 measures to reduce communities and ~ 6 the levels of mercury in the health of z§ 4 and chlorine in the individual 2 stream and the species in East l_lL....lL....J..L....lL.....l!.__LJ--lL_!J.._J.J._...lL...J.L....u..--I.L---LJ---1.1-u....._.J.J...._....u...... J completion of new 0 Fork Poplar co":> co":> coro coro <{;- <{;- coCO coCO coOJ coOJ OJ<:::> OJ<:::> OJ" OJ" OJ'"!- OJ'l.- OJ<>:> OJ<>:> ~ wastewater treatment Creek." The e:;, e:;, e:;, <: e:;, <: e:;, <: e:;, <: e:;, <: e:;, <: e:;, <: e:;, <: e:;, facilities since 1985. evidence Season and year Mercury has been includes - Total c::J Tolerant - Intolerant discharged into the decreasing creek since the early differences in The number of pollution-tolerant fish species in East Fork Poplar Creek just 1950s as a result of various below Lake Reality at the Y-12 Plant has varied from 1985-~rou~h 1994. In separations of lithium .ocheml·cal, the past three years, species of intolerant, or pollution·sens1hve, f1sh have . t t th y. bl . . . th k . d" . . . .t te l"ty 1so opes a e 12 physiological, been I1vmg m e cree , m 1cahng an Improvement 1n 1s wa r qua 1 . Plant in support of the and other indicators of fish health of pollution-tolerant fish species, hydrogen bomb project. Process between the polluted creek and such as striped shiners, green water used at the Y-12 Plant and several reference sites-"clean" sunfish, and central stonerollers. then released to the creek contained creeks that meet acceptable water "Also," says Loar, "we are seeing an chlorine because its source has been quality criteria. increase in the number of species the water-treatment plant that When DOE revealed in 1983 from 5 to 14, including such new provides Oak Ridge's drinking that large amounts of mercury had inhabitants as northern hog suckers water. Successful efforts have been been released to the creek from the and snubnose darters." made to remove chlorine from and Y-12 Plant, very few species of fish Although these changes in the fish keep mercury out of water leaving and other aquatic organisms communities of East Fork Poplar the plant for the creek.

55 Loar says that ORNL researchers have been measuring mercury concentrations in fish at five sampling sites along the creek. ''There has been a decrease in the concentration of total mercury in redbreast sunfish at the site just below Lake Reality," he notes. "This decrease coincides in time with the draining of New Hope Pond and filling of Lake Reality at the Y-12 Plant in November 1988." ORNL scientists have compared the health of individual redbreast sunfish from East Fork Poplar Creek, other polluted streams on the Oak Ridge Reservation, and three reference streams. They have examined indicators of nutritional status, such as fat reserves and levels of liver detoxification enzymes, which are elevated when the fish is exposed to contaminants. With the help of scientists at the University of California at Davis, they have quantified tissue abnormalities in the fish. They have even counted DNA strand breaks, a biological marker for genetic toxicity. Statistical analyses of all these indicators show that the differences between the health of individual fish from polluted sites and the health of those from clean sites have diminished over the past several years. These changes at the molecular, physiological, and histopathological level, when coupled with those observed at the fish community level, are clearly a sign that East Fork Poplar Creek is on the road to ecological recovery. -Carolyn Krause

56 mJ Awards & Appointments

Richard Sincovec Gene McNeese

Richard F. Sincovec has been named review the Department of the Interior's director of the Engineering Physics and newly established Biomonitoring of Mathematics Division. Environmental Status and Trends L.E. (Gene) McNeese has been named Program. director of the Chemical Technology R. J. Michael Fry was selected to be Division. the 18th Lauriston S. Taylor Lecturer at Virginia H. Dale has been appointed the 1994 meeting of the National associate director of the Environmental Council on Radiation Protection and Sciences Division. Measurements. Fred Bertrand has been named acting R. H. Gardner was presented with director of the Physics Division, replacing the Distinguished Landscape Ecologist James D. Ball who has been appointed award by the U.S. Chapter of the acting associate director for Physical International Association for Landscape Sciences and Advanced Materials. Ecology. Edward Oliver has been named The YWCA's 1994 Tribute to Women associate director for Computing, honored ORNL staff members Linda L. Networking, Informatics, and Education. Horton, Monica Turner, Nerrnin A. Robert C. Ward will serve as deputy Uckan, Barbara G. Ashdown, associate director. Margaret W. Terrell, Robin L. Sylvester Scott has been named Graham, and Patricia F. Daugherty. director of technology licensing and Charles D. Scott received the 1994 cooperative research agreements in the David Perlman Lecturer Award from the Office of Technology Transfer. American Chemical Society's S. Marshall Adams has been appointed Biochemical Technology Division. to the adjunct faculty at Duke University. Deborah R. Huntley has been named Lawrence W. Barnthouse has been to the Executive Board of the Tennessee appointed a member of a National Valley Chapter of the American Vacuum Research Council committee that will Society.

Number Three, 1994 57 A WARDS & APPOINTMENTS

Virginia Dale Larry Barnthouse Robert Roussin

Alvin W. Trivelpiece has been named David N. Braski has been named to The ORNL Steam Plant has received to serve on the state of Tennessee's the Executive Board of the Tennessee a Solid Waste Recycling Award from Science and Technology Advisory Valley Chapter of the American Vacuum DOE for diverting six million pounds of Council. Society. fly ash from the Landfill for use in Robert W. Roussin has been named a Louis K. Mansur has been named manufacturing cement. fellow of the American Nuclear Society. chairman of editors for the Journal of Gary K. Jacobs has been appointed to Ralph G. Gilliland ba been named a Nuclear Materials. the technical advisory panel for the fellow of the American Society of Metals James R. Beene has been named a Hanford Low-Level Waste Disposal International. fellow of the American Physical Society. Program. D. L. Williams has been named a Steven M. Gorbatkin has been named Patricia D. Parr has been elected vice member of the Executive Standards to the Executive Board of the Tennessee president of the A ociation of Council of the American National Valley Chapter of the American Vacuum Southeastern Biologists. She also has Standards Institute. Society. been appointed area manager for the Oak Lee Shugart has been appointed to the Ralph M. Moon has been named a Ridge Reservation. Organizing Committee for the National fellow of the American Association for Carolyn T. Hunsaker has been named Institute of Environmental Health the Advancement of Science. to the board of trustees for the Institute of Sciences. Sybil Wyatt, Jon Jefferson, Cindy Professional Environmental Practice and Glenn Suter has been named a fellow Robinson, and Tom Cerniglio have the Advisory Council to the Committee of the American Association for the received awards of Excellence, Merit for the National Institutes for the Advancement of Science. ,and Honorable Mention in various Environment. John B. Caughman has been elected categories of the International Philip M. Jardine bas received the vice president of the Tennessee Valley Association of Business Communicators' Scientific Achievement Award of Chapter of the American Vacuum regional publications competiton for both ORNL' s Environmental Sciences Society. Bringing Science to Life and ORNL '93. Division. G. D. Kerr has been named to serve Van D. Baxter, James R. Sand, and The following ORNL employees and on the Health Physics Society's Edward A. Vineyard have received a contractors have won awards in the Committee on Accuracy in External 1993 ASHRAE Best Symposium Paper Society for Technical Communication's Dosimetry. Award. 1994 Technical Publications

58 Oak Ridge National Laboratory REVIEW Glenn Suter Jim Beene Ralph Moon

Competition: (Distinction) Amanda Wyrick, Jacqueline T. Miller, Janice R. Reichle, Jonathan Woodward, D. Renshaw, Walter Koncinski, S. M. Asher, Lisa K. Sellers, Gay Marie K. Solomon, S. L. Schiff, R. J. Marshall Adams, W. D. Crumby, M. Logsdon, Delores H. Ogle, Linda J. Poreda, Robert J. Luxmoore, S. Greely, Jr., Jim Pearce, Carolyn Jennings, Gloria Caton, Ceramic Maureen Cunningham, Linda K. Krause, Vickie Conner, (Excellence) Technology Project Staff, Kenneth Mann, Cynthia Southmayd, ET/FE Sybil Wyatt, Jon Jefferson, Margaret Rose, James H. Cowan, Jr., P. J. electronic publishers, ET/FE Nestor, Darcus Johnson, Brenda Hanson, S. D. Wullschleger, D. E. graphics team, Po-Yung Lu, and John Smith, Mickie McBee, Carolyn S. Todd, Richard S. Halbrook, Lee R. S. Wassom. Cain, D. L. Selby, Judy H. Campbell, Shugart, Nancy B. Munro, Jim Pearce, The following ORNL employees or Larry W. Davis, Carolyn Krause, Jim Carolyn Krause, Vickie Conner, contractors have won awards in the Pearce, Vickie Conner, Frederick M. Denise K. Casey, Anne E. Adamson, Society for Technical Communication's O'Hara, Jr., Frederick W. Stoss, Betty K. Mansfield, F. J. Peretz, 1994 Art Competition: (Excellence) Gloria Caton, Tim Elledge, Tif'mi Cox, Deborah M. Counce, Judy H. Vickie Conner, Robert A. Hawsey, G. K. Jacobs, N. W. Dunbar, R. T. Campbell, Glenn W. Suter II, (Merit) David Cottrell, Wayne Griest, Williams, Glenn W. Suter II, Robert J. (Achievement) Cheryl Koski, Bob Renee Balogh, Allison Baldwin, Judy Luxmore, Ellen D. Smith, Michael A. Samples, Sandra Schwartz, Richard Wyrick, DOE Human Genome staff, Huston, (Merit) Thomas A. Boden, Genung, Robert Jolley, John Mrochek, Thomas A. Boden, Tommy R. Nelson, Tommy R. Nelson, Frederick M. Martha McReynolds, Paul Greenberg, Frederick W. Stoss, (Achievement) O'Hara, Frederick W. Stoss, Cheryl Bill Gunter, Jr., Anne E. Adamson, Curtis M. Boles, Thomas G. Koski, Bob Samples, Sandra Judy M. Wyrick, Shelia Poligone, Ken Cerniglio, Frederick W. Stoss, Schwartz, Tim G. Elledge, Felicia M. Davis, Marvel Burtis, Robert Frederick M. O'Hara III, and Foust and HTML staff, Judy M. Cushman, Frederick M. Stoss, Donna Frederick M. O'Hara, Jr. ~

Number Three, 1994 59 mJ Educational Activities

Puerto Rico Students Here Last Summer

Harris, a senior who wants to major in engineering, estimated the damage an explosion might create inside an airplane. To qualify for the SEED program, economically disadvantaged students must have at least one year of high school Topics chemistry, a strong included academic record, and a recommendation by a statistics, faculty member. overcomzng Applications go to all schools within driving obstacles to distance of the laboratory a career in and to participating sczence, lnda Rodriguez from Puerto Rico is one of 15 students who participated in programs in Puerto Rico. ORNL's Summer Educational Experience for the Disadvantaged. The The students from Puerto navigating program is designed to encourage students to pursue careers in math or Rico came from the science. Here, she tests th e ability of bottles to contain hazardous gases Comprehensive on the without leaking. Activities for Upgrading Internet, and Sciences Achievement genetic ifteen high school students from Tennessee (CAUSA) program and the preengineering research and and Puerto Rico participated in an eight program of the Ana G. Mendez University F week program at ORNL to encourage System. Both programs host Saturday classes for ethics. minority and economically disadvantaged students students in math, science, and languages. to pursue careers in math and science. CAUSA also selects two teachers from Puerto The Summer Educational Experience for the Rico to participate in ORNL faculty programs for Disadvantaged (SEED), sponsored by the the summer and to chaperone the students. This American Chemical Society (ACS), was in its past year, CAUSA chose Josi Rivera Acosta, a sixth year. The students-ten from Puerto Rico returning participant and secondary-school math and five from Wartburg, Tennessee-studied teacher working in the Computing Applications several different scientific disciplines at ORNL, Division, and Sonia Garcma Hernandez, a including engineering, biogenetics, chemistry, the chemistry teacher working in the Environmental information superhighway, and environmental Sciences Division. studies. The program is coordinated through SEED students participated in special weekly ORNL's Office of Science Education and External seminars in addition to their research initiatives. Relations. This past summer, lecture topics included "This program has helped me to focus on what I statistics, overcoming obstacles to having a career want to study in college," said Dustin Harris of in science, navigating on the Internet, and genetic Central High School in Wartburg. This was research and ethics. Harris' second summer in the Applied Systems Inda Rodriguez, a student from Puerto Rico. Technology Section in ORNL' s Engineering who would like to study chemical engineering, Technology Division. As part of his research, said, "I enjoyed working here because I learned

60 Oak Ridge National Laboratory REVIEW about chemi try and because the people are so summer or semester internships during their college nice." career. "For the past few years, we have averaged a return of five to eight students per year," says Julie DOE's High School Watt , ESD coordinator for the program. "We now Honors Program have a 1988 high school honors graduate working full time with ESD. This program has been a real Fifty-seven students from 48 states, the District success." of Columbia, and Puerto Rico and from France, Students were housed at Maryville College. Four Germany, Italy, Mexico, and Northern Ireland area teachers served as residential supervisors and Each state participated in the Department of Energy's seventh coordinated social activities. selected one annual High School Honors Program July 22 Other activities included tours of the ORNL through August 5, 1994, at ORNL. facilities, seminars, and opportunities to talk with student to The program provided a summer research scientists working in area of special interest to participate in experience for high school juniors and seniors and students. The program is coordinated through a two-week college freshmen who exhibit outstanding ORNL's Office of Science Education and External academic records. Each state and participating Relations.-Kimberly Baker research foreign country selected one student to participate experience in in a two-week research experience in ORNL's Environmental Sciences Division (ESD). Superconducting Motor ORNL's The focu was on small-group, "hands-on" Spins for Students at Environmental laboratory and field research to encourage students EnvironMENTAL Fair Sciences to pursue careers in math and science, especially environmental sciences disciplines. All expenses, A new demonstration motor based on Division. including travel, were paid by DOE. commercial high-temperature superconducting wire Students, working with research staff scientists, was unveiled by ORNL at the recent investigated issues related to the theme of EnvironMENTAL Fair, held October 6, 1994, at the environmental impact. Student teams of two to six American Museum of Science and Energy in Oak member re earched topics such as neutron Ridge. The motor was developed to demonstrate activation analysis of trace elements in soil, electric power uses of new superconducting wires. evaluation of habitat for wildlife, DNA studies of Designed primarily for educational use at area environmental samples, development of a surface schools and museums and for visitor to ORNL, the water hydrology monitoring plan, and motor is the size of a two-pound coffee can and bioabsorption and fermentation a a remediation uses liquid nitrogen to cool the superconductor. technology. Each team prepared a written and oral The heart of the motor is a coil of high report to pre ent their research findings. temperature superconducting wire made of "Theme Groups" in which tudents studied all BSCCO, an oxide consisting of a mixture of sides of an issue of national or global importance, bismuth, strontium, calcium, copper, and oxygen. were a second component of the program. This This coil was supplied by one of ORNL's partners, activity was designed to model a public forum American Superconductor Corporation where students participate in role-playing opposing (Westborough, Massachusetts) as part of an factions. Some of the issues that students explored ongoing collaboration to develop electric power included environmental deficits, toxicants in the applications of high-temperature superconductors. environment, deforestation and sustainable American Superconductor produces flexible high agriculture, obligations to future generations, the temperature ceramic superconducting wires for role of computer networks, data sharing, and ethics coil and systems such as motors and current in cienti:fic data sharing and publication. limiters. The DOE High School Honors Program The superconducting coil produces a magnetic encourages students to return to ORNL for field that interacts with electric current flowing in a

Number Three, 1994 61 EDUCATIONAL ACTIVITIES

ORNLhas produced guides to super conductivity and cryogenics for high school and middle school students.

Middle school students meet the future in the form of a superconducting motor bein g demonstrated by developer Bill Schwente rly of OR NL's Fusion Energy Division.

copper armature to produce the force that causes because they are smaller than conventional motors the armature assembly to rotate. The armature with the same power. current i switched using a brush and commutator The motor demonstrator was developed as part assembly available from a local hobby shop. of the educational activity of ORNL's When fully cooled, the motor rotates at 300 to Superconductivity Program for Electric Power 500 revolutions per minute. The armature Systems. This program is funded as part of DOE' s assembly is constructed from flat-wound copper national effort to develop the technology coils, provided by Advanced Sound, a Knoxville, necessary for U.S. industry to proceed to Tennessee, firm. commercial applications of high-temperature This portable, educational tool operates using a superconductivity. few dry cell batteries and, of course, the liquid In addition to the motor demonstrator, the nitrogen coolant. Liquid nitrogen boils at 77 K ORNL program has produced a ''Teacher's Guide (-321° F), a temperature that is much colder than to Superconductivity for High School Students" the lowest temperature ever recorded at the South and "An Introduction to Cryogenics and Pole. Electric motors and generators using this Superconductivity for Middle School Students." new technology will be more efficient than These guides were produced by teachers who conventional machines. They will consume fewer participated in the Teacher Research Associates of the earth's natural resources such as iron program, a program funded at ORNL by DOE' s

62 Oak Ridge National Laboratory REVIEW Office of Science Education and Technical research experience with seminars, workshops, Information. and courses under the direction of ORNL staff scientists. Three resident faculty members from Oak Ridge Science Semester colleges of the consortium also are assigned to the Laboratory to do research, teach courses, and Is 25 Years Old counsel the students. "This is a very rich program that has grown Students ORNL's Oak Ridge Science Semester Program substantially over the past 25 years," said George perform is entering its 25th year. The program involves Gilbert, director of the Oak Ridge Science undergraduate participants from colleges of the Semester Program. The program has been a research at Great Lakes College Association (GLCA) and the wonderful experience for the students to work the cutting Associated Colleges of the Midwest (ACM). with top-notch scientists and has provided an Deans from the 12 GLCA colleges came to excellent educational opportunity for the edge of ORNL on November 3, 1994, to get a first-hand laboratory." science. look at the program, which has served as a model The 16-week science semester provides for the other DOE laboratories. They also opportunities for student research and advanced attended the annual poster session, highlighting study in energy-related areas of science and the students' research projects. technology, including the biomedical, In this program, students perform research at environmental, and physical sciences; nuclear the cutting edge of science; learn to operate and engineering technologies; applied sophisticated, state-of-the-art equipment and mathematics; and advanced energy systems. instruments; and supplement their laboratory Jennifer Ball ~

Number Three, 1994 63 ORNL Method Removes Ink from Waste Paper

resulted from a discovery made in 1992. At that time, the researchers were trying to use a protein-an enzyme called cellulase to convert waste paper to sugar for fermentation into The ORNL a liquid fuel called ethanol. "We were surprised to technology is find that cellulase easily envzron digests and removes ink mentally from newspapers under certain experimental friendly conditions," says because Woodward. "We found our technique separates high cellulase is quality ink-free pulp fibers produced from ink-covered fibers, naturally by creating a whitish recyclable paper product a fungus. and a gray product that l KED could be used to make egg FIBER boxes, insulation, or combustible fuel." The enzyme, or biocatalyst, technology ha three advantage over the traditional de-inking technology. First, it work on old newspapers that use water-based ink as well as Jonathan Woodward drops shreds of newspaper into the bioreactor oil-based ink, without system that uses an enzyme to separate inked newspaper fibers from de releasing ink to the inked fibers. This environmentally friendly, energy-saving technology environment. helps turn waste newspaper into recycled paper as well as egg cartons, Second, because it insulation, and combustible fuel. requires no de-inking chemicals, it uses much less energy than traditional methods-as much as n environmentally friendly, energy 2.3 million British thermal units less per oven aving technology for removing ink from dried ton of paper. If the technique were used on A waste newspapers to make them the 8 million tons of newspapers collected recyclable has been developed by researchers at annually for recycle, 0.018 quads of energy, or 13 ORNL. million barrels of oil per year, would be saved. The technology was developed by Jonathan Third, the ORNL technology is Woodward of ORNL's Chemical Technology environmentally friendly because cellulase is an Division and two contractor employee from enzyme produced naturally by a fungus that is Midwest Technical, Inc.-Lynette M. Stephan used in wa hing powders such as those for stone and Laurence J. Koran, Jr. The new technique washing jeans. Traditional de-inking technologies

64 Oak Ridge National Laboratory REVIEW use potentially harmful Energy Sciences. The chemicals, such as caustic development of the separation sodium hydroxide, sodium technology was supported by silicate, and hydrogen internal funding through the peroxide. Laboratory Director's Research The new biocatalytic and Development Fund. - technique uses the enzyme Carolyn Krause The device cellulase to treat cellulose can separate fibers making up more than chemicals in half of waste paper. Chemistry Lab Cellulase can completely on a Chip a liquid break down cellulose into droplet in gluco e sugar. However, A "chemistry lab on a chip" under certain conditions might seem like just a only 150 discovered by the researcher's dream, but recent milliseconds. researchers, the action of successes at ORNL suggest it cellulase results only in the could become a reality. desired eparation and A postage-stamp-size pulping of the fibers with instrument for efficiently little cellulose breakdown. Mike Ramsey shows a "chemistry separating and identifying The apparatus used for laboratory on a chip" that he chemicals in liquids is being the process is simple. It helped develop. This miniature, developed by ORNL cientists. consists of two cylindrical micromachined device will offer Such a device could have glass containers, or rapid, inexpensive analysis of widespread use in the liquid droplets for environmental bioreactors, connected by a environmental, manufacturing, monitoring, industrial process tube through which water control, and medical diagnosis. health care, and pharmaceutical circulates. In each container industries. is a cylindrical strainer The ORNL researchers have made of 20-mesh plastic canvas, the porous also shown that microscopic devices can be used material used for needlepoint. to carry out chemical reactions. They have used Waste paper and cellulase are mixed together in the device to separate chemicals in a liquid droplet the trainer in the first bioreactor. The mixing of in only 150 milliseconds. The work suggests that the cellulase with the waste paper separates its an entire chemical laboratory, including chemical large and small pulp fibers and triggers the release containers, "beakers" for mixing chemicals, and of ink from the paper surface. The released ink analysis instruments, can be placed on a tends to stick to the small pulp fibers. microchip. As water flows at 40°C between the two The "chip" is a glass plate as thin as a containers, the small inked fibers pass through the microscope slide and about the size of a postage pores of the plastic strainer and end up in the stamp. A winding, hairlike capillary channel, other bioreactor outside its strainer. The larger covering an area the size of a dime, is etched in the ink-free pulp fibers remain inside the strainer of glass using standard micromachining techniques. the first container because they are too large to The etched channels are closed by bonding a thin pass through the strainer pores. In this process, plate of glass over the top. ink is almost completely removed from paper. "Such a microchip laboratory could provide Woodward says that several paper companies faster, cheaper, and more reliable chemical that have shown interest in the new ORNL analyses for environmental monitoring, industrial technique. Funding for the work that resulted in process control, and medical diagnosis," says the discovery came from DOE's Office of Basic J. Michael Ramsey, one of the developers of the

Number Three, 1994 65 TECHNICAL HIGHLIGHTS

technology. "It could also be used by unskilled a micro copic channel etched in glass. Charged personnel to perform sophisticated chemical molecule of different chemicals move at different analyse in remote locations." speeds based on differences in charge and size. The laboratory on a chip offers several potential Uncharged molecules of different chemicals move advantages over conventional approaches to at different rates based on differing attractions for chemical analysis. Preparation of chemicals for material dispersed in the liquid or coating the analysis is automated, saving Labor and protecting channel walls. human from unnecessary chemical exposure. "With electric field strengths as high as 1500 Also, the amount of chemical reagents needed to volts per centimeter, we have separated chemicals stimulate chemical reactions on a chip is a in liquids in as few as 150 milliseconds, which is "A miniature millionth of the typical volume used in a one of the fastest speeds ever," Ramsey adds. chemical laboratory setting, thus minimizing chemical "This demonstration shows that a miniature device, much waste. Finally, because the miniaturized device ha chemical device, much like a microelectronic no moving parts, it should be more reliable and device, can achieve greater speeds than devices of like a inexpensive enough to be disposable. conventional size." microelectronic Thanks to its greatly reduced size and weight, Ramsey says that chemistry labs on chips could the microchip laboratory could be incorporated be integrated into a miniature chemical factory. device, can into hand-held devices for surveying waste sites Just as several computers can work at the same achieve and diagnosing a patient's disease in a physician's time on different parts of a complex problem, greater office. It could also be part of a small gadget that chemical analysi microchips could work in would be used in chemical process pipes to parallel to synthesize and test new drug . speeds than monitor and control production in a factory. "Te t results might be u ed to influence the devices of "One of our goals i to develop microdevices for next sequence of compounds that is synthesized chemical analysis that demonstrate the same for tests," be says. "This approach could speed up conventional advantages as microelectronics, including small the discovery of new drugs that are effective size." size, low cost, high speed, reliability, and against disease." operational simplicity," says Ramsey. "We have Beside Ram ey, the developers of the designed and tested several types of microchip laboratory include Stephen C. microfabricated chemical separation device . Our Jacobson, Roland Hergenroder, Lance B. Koutny, results show that it is possible to reduce instrument and Alvin W. Moore, all of ORNL' s Chemical size from a few cubic feet to several cubic and Analytical Sciences Division. This work has centimeter and that the performance of the been funded by the ORNL Director's Laboratory miniaturized instruments is equivalent to or better Directed Research funds and by the Department of than the conventional laboratory versions. Energy's Office of Nonproliferation and National "We have also shown that chemical reactions Security.-Carolyn Krause can be performed rapidly in a very small volume using micromachined devices," Ramsey continues. "At ORNL results of a chemical analysis on a chip ORNL Designs were obtained in 5 minutes using reagents in an amount equal to about 11250 of a drop of water. In Radiation-Hardened general, such a device would consume about Memory Chip 1 milliliter of reagent, or the equivalent of 20 drops of water, per year of operation. Researchers at ORNL have designed "Engineers have not been able to design semiconductor chip for collider physics microscopic pumps and valves that work well experiments that may someday be used to help enough for these applications," says Ramsey. "We operate robots in high-radiation environments and do fluid pumping and valving u ing electric fields to make harper, clearer, and steadier television and o motic forces to induce liquid to flow through pictures.

66 Oak Ridge National Laboratory REVIEW Charles L. Britton, Jr., and Alan Wintenberg, both of ORNL's Instrumentation and Controls Division, have designed a radiation-resistant chip for storing information resulting from particle collisions measured in a high energy physics experiment planned for the recently closed Superconducting Researchers SuperCollider (SSC) project. They are atORNL now designing radiation-resistant have circuits for robots that may someday be used to clean up contaminated tanks at designed DOE waste sites. semiconductor For this work in collaboration with Ken Read of ORNL's Physics Division chips for use and Lloyd Clonts, a University of in high Tennessee at Knoxville (UTK) radiation graduate student, Britton and Chuck Britton shows the radiation-hardened memory chip environments. Wintenberg recently received a that he, Alan Wintenberg (center), and Lloyd Clonts (left) Technical Achievement Award from designed at ORNL for manufacture by Harris Semiconductor, Martin Marietta Energy Systems, Inc., Inc. Radiation-hardened circuits may be used in robots which manages ORNL for DOE. They designed to perform cleanup operations in high-radiation were cited for "superior contributions zones. to the experimental physics community by developing the world's first radiation-hardened analog memory unit." chips are supposed to be able to withstand as The researchers have also designed a less much as 10 million rads of radiation," Britton expensive chip not hardened against radiation for says. "By contrast, ordinary chips would be use in collider physics experiments at other destroyed by about the same amount of radiation accelerators. "Chips like these," Britton says, that kills a cockroach-20,000 to 30,000 rads, "could be used for storing television signals long about 50 times as much as would kill a human." enough to process them into improved TV images. The SSC, which was terminated by the U.S. By processing the stored signals in a few Congress in 1993, was being designed to millionths of a second, TV pictures could be made accelerate protons to extremely high energies clearer, sharper, and steadier." traveling in opposite directions around a 54-mile The radiation-hardened chip was made by a ring in Texas. One object of research using the special process for manufacturing complementary machine was to understand the most basic metal oxide semiconductor (CMOS) chips. Harris particles of matter and the glue that holds them Semiconductor, Inc., of Melbourne, Florida, together. developed this process to meet military needs. The proton beams were to be slammed Britton and his colleagues developed circuits together in the central tracker system of the using computer-aided design and drafting tools eight-story-high gamma-electron-muon (GEM) and sent the designs to Harris by electronic mail. detector being designed for the SSC. ORNL was Harris then manufactured about 200 chips to meet asked by DOE to develop radiation-hardened ORNL's specifications. chips to store information about the particles To determine each chip's resistance to radiation shooting out in all directions during head-on damage, the ORNL researchers subject them to collisions of protons 62 million times a second in gamma radiation from a cobalt-60 source. "These the opposing beams.

Number Three, 1994 67 TECHNICAL HIGHLIGHTS

"The chips bad to be hardened against radiation National Laboratory in New York and an existing because of the highly energetic gamma rays and accelerator at the European Center for Particle neutrons produced from proton collisions and Physics (CERN) in Geneva, Switzerland. other particle interactions," Britton says. "They The CERN experiment is the W A98 should be able to operate even with a little experiment, one in a series of experiments aimed radiation damage by recalibrating their memories." at creating a plasma of free quarks, the basic "There was no practical way for the SSC to constituents of particles in atomic nuclei, and immediately process information on all the gluons, the particles that bind quarks together. It particles, their energies, and the directions and is believed that a superhet quark-gluon plasma distances they travel," Wintenberg says. "A lot of was fir t formed during the Big Bang that created the information would be of no interest because it the universe and that, within several millionths of Radiation would result from protons passing by each other or a second, the plasma cooled into the atoms hardened glancing off each other rather than directly making up the universe. Glenn Young, Frank chips may be colliding. So analog memory chips were needed in Plasil, and others in ORNL's Physics Division the sse to store all electrical information as have worked on these experiments since 1986. used in a voltages until computers decide which information "In the past," Britton says, "they have used planned might be significant to reconstruct particle tracks, conventional electronics developed at ORNL for for example. Such voltages would then be these experiments. But for these new experiments Swiss converted to numbers for computer processing." they will use custom chips from ORNL for the accelerator. The ORNL chip consists of many capacitors, first time." transistor switches, amplifiers, and associated The funding for developing radiation-hardened circuitry. In the sse the capacitors would have analog memory chips for the sse came from stored electrical signals as voltages from charged DOE through the SSC Laboratory in Dallas, wires in gas-filled detectors. These wires would Texas. DOE' s Office of Energy Research also has have picked up electrical charges produced when been supporting development of the other chips particles from proton collisions passed through for the Brookhaven and CERN accelerator each detector, stripping electrons from gas experiments. molecules. The voltages of interest stored on the chips would have been turned into numbers for computer use by analog-to-digital converters. Gas from Grass? "Radiation-hardened chips will not be needed A Promising Biofuel for the SSC now because of its demise," Read says, "but they may be used in a somewhat smaller The automobile engine of the future may be collider to be constructed in Switzerland for grass-powered, not gas-powered. Wouldn't that experiments in which U.S. scientists will be a switch? participate. Other uses would be for robots that Environmental scientists at ORNL are working work in high-radiation environments such as to develop a fast-growing grass as a source of nuclear power plants or waste sites." liquid fuel. The Biofuels Feedstock Development The ORNL researchers are now working with Program at ORNL has selected a native grass ORBIT Semiconductor to produce CMOS chips species for further studies in alternative-fuel that have similar circuit designs but are not development. The species is called switchgrass. radiation hardened. These chips can be made for a Scientists and politicians alike realize the much lower cost than the radiation-hardened ones. importance of developing clean, renewable These memory chips will be used for relativistic sources of energy. Today, much of the world heavy-ion physics experiments involving ORNL depends on oil reserves that are concentrated in a physicists. Several applications are planned for the handful of nations. Another problem is pollution, PHENIX experiment at the Relativistic Heavy Ion much of which stems from fossil-fuel use. Collider Center under construction at Brookhaven Conversion of woody and herbaceous plants into

68 Oak Ridge National Laboratory REVIEW clean-burning fuel offers an attractive possibility for meeting future energy demands, researchers say. Switchgrass is a perennial warm-season grass that grows well in many areas of the country even on fairly dry, nutrient-deficient land of marginal quality-and it has positive environmental attributes. Its natural range extends from Quebec through Mexico and into Central America. Switchgrass has two growth forms. One is a One acre of leafy, thicker-stemmed variety common to harvested lowland sites in the Southeast. The second form is shorter, fine-bladed, and more typical of grass switchgrass in the western plains. Both were abundant on the could native prairie when American pioneers arrived. produce as The ORNL program emphasizes the need for high-yield crops that can be grown economically much as 500 over a wide area and with minimum impact on gallons of the environment. Switchgrass was selected as a model herbaceous crop because it has high, stable fuel. yields and relatively low production costs. Its Sandy Mclaughlin examines switchgrass on the other positive environmental attributes include Oak Ridge Reservation. Such grass shows relatively low need for pesticides and fertilizers promise as a feedstock for producing fuel. and excellent soil conservation potential. These features could make switchgrass tremendously Colorado. There engineers work to develop more beneficial to owners of small farms in a depressed efficient ways to convert biomass to liquid and agricultural industry. gaseous fuels. By the 21st century, energy crops "One reason switchgrass was selected as a fuel could yield more than 230 million gallons of alternative is that it is very similar to hay in the ethanol annually, or about 650,000 gallons of way it is raised, making its production compatible ethanol every 24 hours. with traditional agricultural practices," says The research at ORNL is supported by DOE' s Sandy McLaughlin, an ORNL senior research Office of Transportation Technologies through the staff member and a task leader in the ORNL Energy Efficiency and Renewable Energy biofuels program. "In fact, the equipment used Program. for harvesting hay can also be used for Research at Virginia Polytechnic Institute and switchgrass, helping to lower the front-end costs State University has shown that deep switchgrass for farmers who want to grow switchgrass and rooting patterns improve soil quality by increasing sell it to conversion facilities." soil carbon content. This ability to transfer carbon McLaughlin says that 100 gallons of fuel could dioxide from the air to the soil will help offset be produced per dry ton of harvested switchgrass. carbon dioxide emissions to the atmosphere, a The amount of fuel produced per acre of significant global pollution problem. harvested switchgrass could be as high as 500 Switchgrass protects against erosion, has low gallons. fertilizer and pesticide requirements, and provides Research on developing fast-growing grasses cover for wildlife. But someday it may have a new and hardwoods for the ORNL program is claim to fame. Americans may eventually be paralleled by research at DOE's National talking about making gas from grass.-Angela Renewable Energy Laboratory in Golden, Swatzell and Wayne Scarbrough

Number Three, 1994 69 TECHNICAL HIGHLIGHTS

conventional auto engine-the expansion force Revolutionary that results from burning fuel. Auto Engine Conceived However, in the LM engine, the connection from expansion force to electric power generation An ORNL researcher has designed a is made without any mechanical devices such as revolutionary "liquid-metal" automobile engine connecting rods, crankshaft, pulleys, or belts. that can change size, depending upon acceleration Thus, the engine ha fewer moving parts and requirements. No prototype is yet available, but problems with friction. detailed schematic drawings have been made. "The LM engine can adjust its output to suit As conceived, the engine could provide high different driving requirements, ensuring superb level performance when desired, would cost less vehicle performance and maximum fuel efficiency than conventional automobile engines, and should at any speed," Haaland says. "Because there are offer economy-minded drivers the possibility of fewer moving parts in the engine, and because an "The LM 38 kilometers per liter, or 80 to 90 mile per auto powered by it won't need a clutch or engzne can gallon, of gasoline, for a lifetime mileage of at transmission, the initial vehicle costs should be least 805,000 kilometers. lower and the frequency of repairs should be adjust its Carsten M. (Kit) Haaland of ORNL's greatly reduced. output to suit Engineering Physics and Mathematics Division "Because the engine displacement volume can different has invented a magnetohydrodynarnic liquid expand quickly," Haaland says, "a driver will be metal (LM) engine that can "shrink" the engine able to push the accelerator pedal to the floor and driving combustion volume down to around 0.06 liters, get an exciting response from an engine that has requirements, which is much smaller than that found in existing suddenly increased its available power up to 10 commercial automobile . The engine volume can times. The driver could then let up on the gas ensurzng expand by a factor of 10 to 0.6liter in about one pedal to shrink the LM engine volume when the maxzmum second when needed. The smaller engine volume desired speed is reached. The LM engine could fuel will burn just enough fuel at high-efficiency provide the driver up to 80 miles per gallon of fuel steady cruising, whereas the larger engine volume at a constant peed of 65 miles per hour, and up to efficiency at will take a lightweight vehicle to 96 kilometers 100 miles per gallon at a steady 55 miles per hour any speed. " per hour, or 60 miles per hour, in just seven on a smooth level surface." seconds. Haaland's part of a 1990 study supported by the Martin Marietta Energy Systems, Inc., has Laboratory Director's Re earch and Development applied for a patent for the magnetohydrodynamic Fund resulted in the variable-size LM engine. He engine. Magnetohydrodynarnics is the science of conceived the idea for a four-piston double-duct magnetic fields combined with the motion of LM engine in 1992. The four-piston setup is used liquids that conduct electricity, such as mercury or to drive the LM engine back and forth in opposite liquid odium. directions in two separate ducts. This arrangement The output of the LM engine i electric power eliminates vibration and instabilities in the LM in the form of alternating current (ac) at variable motion that result from strong magnetic fields. It frequencies that match the variable rotational also allows a transformer to be conveniently frequencies of car wheels. The electrical output of connected to one side of the double-duct to step the LM engine is fed by wires directly to ac up voltages and step down currents to practical motors that provide rotation in the driving wheels. levels. A specially designed computer chip would Unlike a conventional electric generator or auto control the operation of the LM engine and the engine, the LM engine has no rotating parts. vehicle. The electric power is generated by the back The variable-size (variable-displacement) LM and-forth motion of the LM engine in a strong engine uses free pistons, with no connecting rod magnetic field. The driving force for this motion or solid metal attachments. The pistons are driven comes from the same force that drives a by combustion of a liquid fuel, such as gasoline,

70 Oak Ridge National Laboratory REVIEW Combustion Combustion cyl inder 1 cylinder 2

AC power output: Combustion Variable frequency cylinder 4 Variable power

This revolutionary magnetohydrodynamic liquid metal (LM) engine conceived at ORNL should achieve a fuel efficiency of at least 80 miles per gallon. In this variable-size LM engine, the distance the gasoline driven pistons travel is limited by the quantity of liquid metal in the ducts. If the liquid metal is pumped out of the duct back into the reservoir, the piston stroke gets longer, resulting in more flow of the liquid metal through the magnetic field from the nearby magnet; as a result, more electri city is produced to power the wheels. This arrangement allows the LM engine size to vary according to need. diesel fuel, liquid propane, or some combination. remain sealed against the chaotic forces of Each pair of pistons is linked by a duct containing collision. To prevent any contact with air or liquid metal, the source of which is a nearby water, the liquid metal is sealed permanently in reservoir. The distance the pistons travel is limited two channels. Approximately two liters (slightly by the quantity of liquid metal in the operating more than two quarts) of liquid metal would be ducts: the more liquid metal, the les piston used in a typical LM engine. movement. "There are no load-bearing sliding surfaces in If the liquid metal is pumped out of the duct the LM engine. The sideward push of pistons back into the reservoir, the piston stroke gets against cylinders in the usual engine is eliminated, longer, resulting in more movement of the liquid and no crankshaft, connecting rods, wrist pins, metal through the magnetic field produced by and their associated bearings are required," nearby magnetic material; as a result, more Haaland says. "Thus, the engine will experience electricity is produced to power the wheels. This less load from internal friction. Stress points on arrangement allows the LM engine size to vary connecting rods and wrist pins are eliminated. according to need. "Because of these features, the LM engine Such an engine requires liquid metals that have could operate up to 300 cycles per second in a high electrical conductivity, low density, and low two-cycle mode with greatly improved viscosity. The most favorable liquid metals fo r scavenging, resulting in much smaller engine size this purpose are members of the alkali metal per kilowatt. All these factors, including the use family, such as liquid sodium, liquid potassium, or of air cooling instead of water cooling, result in a combination of these. Because they will bum less weight, improved fuel efficiency, lower cost, spontaneously in air or water, the ducts carrying and longer life for the LM-engine-powered liquid metal in the engine must be designed to vehicle.

Number Three, 1994 71 jRE:

ORNL Wins Two R&D 100 Awards

Tarasankar Pal, all of ORNL' Health Sciences Research Division. The ORNL co-developer of "parallel virtual machine" (PVM) oftware is AI Geist of the Engineering Physics and Mathematics Division. Two R&D Collaborating with him on thi development were V. S. Sunderarn 100 awards of Emory University in Atlanta, R. J. in 1994 Manchek and J. J. Dongarra, both of the University of Tennessee at bring Oak Knoxville, and A. L. Beguelin of Ridge's total Carnegie-Mellon Univer ity in to 84. Pitt burgh. R&D magazine has annually honored inventors and scientists around the world since 1963 by selecting the 100 most technologically significant new products and processes.

* * *

The newly developed PCB test u es strips of chemically treated paper that glow under ultraviolet (uv) tight if the environmental sample being tested is contaminated with PCBs. The improved process Tuan Vo-Dinh conducts a test to determine if a liquid sample is saves money by eliminating costly contaminated with PCBs. Vo-Dinh and his research associates laboratory procedures and extra received an R&D 100 Award for developing the PCB test. work time. Before Vo-Dinh's innovation, researchers had to collect samples on site and then transport wo of the top 100 new technologies them to a laboratory for chemical analysis to recognized in 1994 by R&D magazine determine whether they were contaminated. T were developed or co-developed by ORNL "The PCB strip test will cost ten times less than researchers. The total number of R&D 100 awards previous methods because it uses a simple process for Department of Energy plants in Oak Ridge is called photoactivated fluorescence, allowing quick 84. analysis at the site," says Vo-Dinh, leader of the The winning ORNL technologies are an Advanced Monitoring Development Group at improved method of testing for polychlorinated ORNL. "A user of the test can rapidly screen biphenyls (PCBs), a significant environmental samples for PCBs and even measure the level of contaminant, and a computer software package contamination." that virtually turns computer workstations into When the patented process is developed fully supercomputers. for large-scale field use, testing a sample could The developers of the PCB test strip are Tuan cost only a few dollars. "However," Vo-Dinh Vo-Dinh, Anjali Pal, Lorna Ramirez, and notes, "the raw material for each sample run-the

72 Oak Ridge National Laboratory REVIEW chemically treated paper test strip--costs less than PVM is particularly useful in linking several a penny." computer workstations during off hours to solve The research project was sponsored by DOE's problems that normally would be submitted to a Office of Health and Environmental Research, the more powerful mainframe computer. Perhaps best Environmental Restoration and Waste of all, says Geist, the software is available free Management Office of Technology Development, through an ORNL electronic mail network. "It's and the Environmental Protection Agency's an example of your tax dollars at work," he says. Environmental Monitoring Systems Laboratory in (The Internet address to access PVM is http:// Las Vegas. www.netlib.org/index.html.) PCBs were manufactured in the United States Geist notes that the PVM system could be PVMis from 1929 to 1977. They were used in electrical viewed as "a poor man's supercomputer." By particularly equipment, such as transformers and capacitors, using it to tap the aggregate power of computer useful in and in hydraulic fluids and lubricants for workstations whose combined cost is roughly industrial equipment. Through such products, $250,000, researchers have achieved computing linking PCBs made their way into the environment. speeds that rival those of $20 million several The disposal of PCBs was not regulated until supercomputers. The package has been applied to the late 1970s, when studies first showed that as many as 125 workstations. It can even be used computer these toxic compounds persist in the environment to link supercomputers. workstations and may cause cancer. "The workload achieved," Geist says, "is during off In the new test, a drop of liquid from an limited only by the number and power of environmental sample is applied to a paper test computers to which you have access." hours to strip coated with special chemicals that are The software also allows linking of several solve activated by uv light if exposed to PCBs. UV computer networks, such as Ethernet and Token light is then shone on the strip. If PCBs are Ring, to form a single PVM configuration. problems. present, the activator molecules on the test strip PVM will be particularly beneficial to will absorb the uv energy, interact with the PCBs, universities, most of which cannot offer courses in and glow. The intensity of the glow is measured in supercomputing because of the high cost of the a luminescence analyzer, which indicates the level hardware. "With PVM," Geist says, "universities of PCB contamination. can teach students how to write parallel programs that apply to supercomputing even though they *** could never afford a supercomputer." PVM is being used at hundreds of sites The PVM computer software package worldwide by companies whose business ranges developed by ORNL's Al Geist and others from aerospace, automotive, and chemical virtually turns computer workstations into research to medicine and the environment. PVM supercomputers. The software allows is supported on more than 30 different types of organizations and individuals with computers to workstations and supercomputers, including those tap the power of several workstations manufactured by IBM, Hewlett Packard, DEC, simultaneously, thereby solving problems that Sun, Cray Research, Convex, Silicon Graphics, would be too large or complex for a single and Intel. workstation. Parallel computing using the PVM system may PVM is one of the first software systems to be the key to solving so-called computational allow computers with widely different grand challenges, such as modeling of the global architectures and data formats to cooperate climate, groundwater transport of hazardous simultaneously on a single computational task. waste, and the structure of superconductors. Their combined power can equal that of "At this time, these problems can't be solved multimillion-dollar supercomputers, at a fraction because of a lack of computer power," Geist of the cost. notes. "One computer, even a supercomputer,

Number Three, 1994 73 R&D UPDATES

Parallel computing using the PVM system may be the key to solving so-called computational grand challenges.

AI Geist, co-developer of "parallel virtual machine" software and a winner of an R&D 100 Award, explains that several computers linked together (shown as icons) can work on different parts of the same problem.

simply has physical limitations. Parallel accelerator facility to study nuclear reactions computers will be required to solve these predicted to occur during the birth and death of problems." stars. PVM research is sponsored by the Applied On October 20, 1994, the Daresbury Recoil Mathematical Sciences Research Program of Separator, which has been donated to the DOE's Office of Energy Research. Laboratory, was delivered to ORNL for use in its new Holifield Radioactive Ion Beam Facility (HRIBF), now being constructed and expected to Nuclear Physics Device begin operation in the fall of 1995. HRIBF will be for ORNL Accelerator the only U.S . facility dedicated to producing and Arrives from England accelerating intense beams of radioactive nuclei. The two accelerators that formed the heart of Although the Daresbury Laboratory in England the Holifield Heavy Ion Research Facility from was closed on March 31 , 1994, one of its nuclear 1980 to 1992 are being reconfigured. One will be physics instruments will have a second life at used to produce radioactive nuclei that do not ORNL. The large, multimillion-dollar instrument occur naturally, and the second will be used to will be used with ORNL's upgraded heavy-ion accelerate them. When radioactive nuclei

74 Oak Ridge National Laboratory REVIEW bombard a target, particles called recoils are produced. The Daresbury Recoil Separator will direct these recoils to detectors while steering away radioactive beam particles. "The ability of the Dares bury Recoil Separator to separate recoil products from projectile particles makes it a tremendous addition to our research program," says Jim Ball, acting ORNL associate director for "This Physical Sciences and instrument Advanced Materials. "Combining this instrument will enable . . with ORNL' s unique pzoneerzng radioactive beams will enable advances in pioneering advances in our Physicist Michael S. Smith (pointing) and engineer Don Pierce understanding of the explosive admire a 19-ton velocity filter magnet. It is one of 14 magnets in the our events that create and destroy Daresbury Recoil Separator, wh ich was sent from a closed facility in understanding stars." England to be an important part of ORNL's Holifield Radioactive ion The recoil separator came to Beam Facility. The magnet will separate by velocity the heavy ions of the ORNL from the Nuclear leaving targets bombarded by radioactive ion beams. explosive Structure Facility of the Daresbury Laboratory in events that Warrington, England. The facility was closed radioactive nuclei like those that will be produced create and because of budget cutbacks in the United in our new radioactive ion beam facility. Such destroy Kingdom. The Physics Division staff of the important measurements would not be possible Holifield Heavy Ion Research Facility, which without instruments such as the Daresbury Recoil stars." faced budget cutbacks of its own in 1992, was Separator." successful in securing a new role for the Holifield This separator generates magnetic and electric facility. Approved for construction in 1992, the fields that selectively focus the recoil products new HRIBF will begin operating in 1995. The onto detectors while steering away the projectile physicists will use these capabilities to study beam particles. The detectors generate nuclear structure and to conduct nuclear information on the arrival time, position, and astrophysics research. energy of the recoil products; these data are "Radioactive beams at ORNL will be used to processed electronically and sent to a computer study nuclear reactions occurring in exotic stellar for storage and analysis. The information obtained explosions such as novae, supernovae, and X-ray may help scientists understand the structure of bursts," says Michael Smith of the Physics some 100 nuclei that cannot be produced with Division. "These incredibly energetic nonradioactive beams and targets. astrophysical events produce the majority of The Daresbury Recoil Separator is 13 meters heavy elements in the universe and mark the long and weighs about 90 tons. Its components dramatic end of the life of massive stars. include two 18-ton dipole magnets surrounding "Sophisticated computer models of these vacuum chambers containing high-voltage explosions," Smith continues, "require precision electrostatic plates. These components form two measurements of nuclear reactions involving velocity filters that separate the radioactive beam

Number Three, 1994 75 R&D UPDATES

particles from the recoil products based on producing heavy ions at ORNL. ORIC was used differences in their direction and speed. part-time to boost the energy of the heavy-ion "The transfer of the Dares bury Recoil beams emerging from the tandem accelerator. Separator from England to ORNL required the Now, in a reversal of roles, ORIC will produce cooperation of researchers and technical staff the radioactive beams and the tandem accelerator from both laboratories," says Jerry Garrett, will accelerate them. scientific director of HRIBF. "We anticipate that Just as many people switch careers at least this cooperative spirit will continue through twice, a cyclotron's role can also change more than research collaborations between ORNL once. -Carolyn Krause physicists and those from Dares bury Laboratory Now, in a and sites throughout the United Kingdom. Such Greenhouse Gases reversal of collaborations will greatly benefit research and Forests roles, OR/C efforts in nuclear astrophysics, nuclear structure physics, and radioactive beam physics on both Researchers at ORNL have created an will produce sides of the Atlantic Ocean." experiment to test the effects of regional the precipitation changes on forests. In the experiment, Cyclotron Reaches Goal for an oak forest is being manipulated to show the radioactive Radioactive Beam Facility effects of drought, normal precipitation, and heavy beams and precipitation on different tree species. the tandem The Oak Ridge Isochronous Cyclotron (ORIC) Scientists worldwide predict that the greenhouse has proven that it can still carry out its original effect will increase global temperatures and alter accelerator mission-produce intense beams of light ions, regional levels of precipitation. Temperature will such as charged atoms of hydrogen and helium. increases of approximately 3 to 5°C (5 to 10°F) The difference today is that ORIC, the could occur in 60 to 70 years-a short time accelerate Laboratory' s only cyclotron, is being used to compared to a mature tree's life span, which can them. produce ractioactive rather than stable ion beams. be several hundred years. A cyclotron is an accelerator in which charged The projected change in precipitation has led particles are propelled, often in a circle, by an researchers in ORNL's Environmental Sciences alternating electric field in a constant magnetic Division to ask a key question: With some change field. in precipitation, will current forests be able to On March 10, 1994, an important milestone maintain current levels of growth and ecological toward developing ORNL's new Holifield diversity? Determining the sensitivity of forests to Radioactive Ion Beam Facility was achieved. changes in soil moisture will provide information ORIC produced a 75-million-electron-volt beam on one of the effects of increasing atmospheric of alpha particles (helium nuclei). concentrations of greenhouse gases. "This is the first time since 1983 that a beam The experimental site for the precipitation was extracted from ORIC using the internal ion studies is a part of the Walker Branch Watershed source," says Fred Bertrand, acting director of on DOE's Oak Ridge Reservation, which has been the Physics Division. "This achievement marks a used for ecological research for more than 25 major milestone in the Physics Division's years. The site was chosen for this experiment development of a radioactive ion beam facility." because the forest has not been disturbed by other ORIC was built in 1964 to produce intense experiments or heavy use. According to Paul light-ion beams. But its mission changed in 1970 Hanson, a project researcher, this project is the to the production of heavy ions, which were largest experimental manipulation of an oak forest. needed for nuclear physics experiments. From The site, which is approximately the size of 1980 to 1992, the 25-million-volt tandem three football fields, consists of a wet plot, a accelerator, the workhorse of the Holifield Heavy control plot, and a dry plot of equal length and Ion Research Facility, took up the burden of width. The amount of precipitation distributed to

76 Oak Ridge National Laboratory REVIEW the wet and dry plots is controlled by a series of plastic, gutterlike troughs. Each trough is 0.3 meter (I foot), and they are spaced ' , Rain 0.6 meter (2 feet) apart. Approximately 2000 troughs intercept about 33% of precipitation falling onto the dry plot-a level chosen to reflect drought levels from the mid-1980s. The intercepted rainwater then flows to the wet plot. The Researchers control plot receives natural hope the precipitation. Trees are unlikely to die watershed during the current three-year experiment experiment, but researchers will provide hope to see trends that will The Walker Branch Watershed is the site of a "throughfall displacement help them predict the plight experiment" designed to test the effects of regional precipitation an of forests in several years or changes on different tree species. understanding decades to come. One prediction is that tall compose one team studying how Armillaria, a of how trees with deep roots may buffer themselves pathogenk fungus, will affect oaks when climate against short-term droughts because their roots precipitation levels change. Don Shure of Emory change will will be able to reach deep water supplies. For University is studying changes in insect feeding example, oaks are considered to be more tolerant patterns in forests in response to precipitation affect forests of droughts than are maples. changes. before the The data gathered by this experiment will be Researchers hope that the watershed applied to other types of trees. However, the experiment will provide several ecological effects are experiment cannot be generalized to all regions in scenarios on which to base further research, and irreversible. the United States because each region's plant life an understanding of how climate change, is specifically adapted to that region's climate. influenced by increasing atmospheric The precipitation experiment is composed of concentrations of greenhouse gases, will affect four studies funded through the Program for forests before the effect are irreversible. Ecosystem Research, Office of Health and Kimber/y Baker Environmental Research, DOE. These four studies examine the ability of deciduous forest species to tolerate and survive periods of drought, ORNL-Produced Isotope observe changes in below-ground processes, and Used in Recently Approved quantify alterations in forest productivity and Bone Pain Treatment water use under the manipulated conditions of changing moisture levels. A therapeutic radioisotope recently approved in Several collaborators are conducting the United States for relieving cancer-induced complementary research on the experimental site. bone pain is produced from a material enriched in Ted Leininger, U.S. Forest Service, and Johann a stable isotope by ORNL. The treatment, called Bruhn, University of Missouri at Columbia, Metastron, is manufactured and marketed by

Number Three, 1994 77 R&D UPDATES

Amersham International in England. The targets enriched in strontium-88 by ORNL. The company's division Medi-Physics, Inc., in source of the strontium-88 is a et of calutrons at Arlington Heights, lllinois, is distributing the Oak Ridge Y-12 Plant operated by ORNL' s Metastron throughout the United States, where it Isotope Enrichment Group headed by Joe Tracy. i expected to have widespread u e. The calutrons, which separate isotopes In the past seven years, Metastron has been electromagnetically, were originally used to used worldwide for more than 6000 patients to produce enriched uranium for the Manhattan reduce metastatic bone pain-pain caused when Project during World War II. We continue breast and prostate cancer spreads, or "Since the early 1980s," Tracy says, "ORNL' to support metastasizes, to bone. Metastron was not Isotope Enrichment Program has collaborated with employed in the United States for managing Amersham in development of the Metastron Amersham in metastatic bone pain until recently, following its product, and we continue to upport Arnersham in providing June 1993 approval by the U.S. Food and Drug providing certified, high-quality strontium-88. certified, Administration (FDA). "The ORNL group does not certify i otopes for Metastron, which consists of strontium-89 human consumption," Tracy says. "However, our high-quality chloride, is used to treat bone pain because quality-assurance documentation and certification strontium-88. strontium-89 localizes in bone as a result of it of the starting strontium-88 played an important chemical similarity to calcium and because its role in Arnersham's obtaining FDA approval for radioactivity reduces tumor growth in bone. Its Meta tron." effectiveness reduces or eliminates the need for By electromagnetically separating the isotopes chemotherapy or addktive narcotics to relieve of naturally occurring strontium in a single pas , an pain. This nonsedating drug eliminates bone pain ORNL calutron produces materials enriched in for up to six months with a single injection. It more than 99.8% strontium-88 for fabricating improves patient quality of life, especially mood, strontium-88 carbonate targets. After neutron mobility, appetite, and sleep patterns. irradiation, the e targets are converted to a According to the December 1993 issue of strontium-89 chloride solution, which i injected Reader's Digest, Metastron leaves patients alert, into patients. allowing them to participate in normal activities. Tracy says the enrichment process almost "Dr. Ralph G. Robinson at the University of completely eliminates the strontium-84 Kansas Medical Center has studied Metastron in contaminant from the enriched target. Exposure of more than 600 patients," the magazine state . strontium-84 to neutrons in a reactor yields "About 80% get relief," he says. "And for some, strontium-85, which emits penetrating garnrna rays pain disappears completely." that could harm patients. Strontium-89, which has The strontium-89 in Metastron i produced in a half-life of 51 days, emits pure beta radiation, five European reactors by neutron irradiation of energetic electrons that have a very short range.~

78 Oak Ridge National Laboratory REVIEW CII Technology Transfer

Predicting Properties of Chemicals Using Neural Networks

FreonTM in heat pump compressors and car air conditioners. MOLDESIGN has the capability of evaluating numerous possible FreonTM substitutes and determining the best candidates that could be used in existing equipment MOWESIGN without changing its design and parts. The best compounds can predict wo uld have the desirable physical, properties of Freon TM but would not destroy earth's protective chemical, ozone layer and increase the and likelihood of skin cancer and mechanical cataracts caused by ultraviolet radiation from the sun. properties of The computational approach compounds was developed by Andre Gakh (a postdoctoral scientist), Bobby before they Sumpter, and Don Noid, all of are ORNL's Chemical and synthesized. Analytical Sciences Division. MOLDESIGN can screen present and predicted compounds to identify materials with desired properties. This capability could save U.S. industry millions of dollars in testing costs as it searches for Bobby G. Sumpter (sitting) and Don Noid have helped develop more effective drugs, explosives, MOLDESIGN, a "neural network" computer program that can predict and metallic alloys and plastics. properties of almost any chemical, based on its structure and elemental composition. "MOLDESIGN's ability to predict physical, chemical, and mechanical properties of compounds before they are RNL researchers have developed a synthesized can be very useful," Sumpter says. "It computer program that can predict can guide a material's design and processing to 0 physical properties of some classes of get the best product. chemical compounds based on their chemical MOLDESIGN, Noid says, is particularly useful names. The inexpensive personal-computer for polymers, the large molecules formed from software relies on a neural network, a "learning chains of smaller molecules that make up plastics. computer" that can be trained to recognize MOLDESIGN can be used to predict the patterns and make associations. It is fast, accurate, properties of different blends of polymers. and easy to use. Sumpter adds that it has the capability to identify Already ORNL researchers have used the the best processing technologies for making program, called MOLDESIGN, to address the polymers that have desired properties such as recent ban on the production and use of common increased hardness or stiffness.

Number Three, 1994 79 TECHNOLOGY TRANSFER

"A neural network," Sumpter says, "can be System (IVHS). The nation's first IVHS constructed to predict correctly the properties of CRADA is supporting the crash-avoidance chemical compounds based on structural features research project. and elemental compositions. This capability Scientific-Atlanta is a communications provides the foundation for designing new company whose task is to develop and provide an compounds or for predicting properties of existing automotive data processing unit, compressed The key to compounds that have not been previously video digital storage and retrieval system, and characterized." communications equipment. ORNL's expertise in developing MOLDESIGN was developed at the human factors research (e.g., identifying the most crash Laboratory as part of a 1992 cooperative research effective ways to display and communicate and development agreement (CRADA) between reactor control information to human operators), avoidance Martin Marietta Energy Systems, Inc., which advanced technology, and instrumentation and systems for manages ORNL for the Department of Energy, controls will be called upon in the CRADA. cars and and Hoechst Celanese Corporation, an Richard J. Carter is ORNL's principal international manufacturer of fibers, chemicals, investigator for the CRADA and a psychologist in trucks is to plastics, and pharmaceuticals, which is the Engineering Physics and Mathematics understand headquartered in Germany and has an office in Division (EPMD). Working with him on this Summit, New Jersey. The development was project at ORNL is Frank Barickman, a senior at the detailed supported by Y -12 Plant funds obtained from Gannon University in Erie, Pennsylvania, who is behavior of DOE's Defense Programs. participating in a program sponsored by the Oak drivers and This CRADA, called Atomistic Simulations of Ridge Institute for Science and Education and Materials: A Neural Network Approach, is part of DOE. Another collaborator on the project at vehicles. a larger CRADA called Materials by ORNL is Philip F. Spelt of EPMD. Computational Design involving DOE's Oak Carter says the key to developing crash Ridge Y-12 Plant, Lawrence Livermore National avoidance systems for cars and trucks is to Laboratory, Los Alamos National Laboratory, and understand the detailed behavior of drivers and Sandia National Laboratories. vehicles under a variety of road and traffic conditions. Avoiding Car Crashes "We are primarily interested in the changes that Subject of CRADA occur right before an accident or near miss, such as an increase in speed," Carter explains. "These ORNL is collaborating with Scientific-Atlanta, specially equipped vehicles will be used on a test Inc., on research that could reduce the number of track and the open road to test the effects on deaths and injuries from vehicle collisions. The driver performance of various conditions ranging partners will develop a device to study both driver from the weather to traffic congestion." and vehicle behavior, and the information could Using high-speed digital data processing aid in the design of crash avoidance systems for equipment and specially developed software, cars and trucks. Scientific-Atlanta and ORNL will develop a ORNL and Scientific-Atlanta will develop a prototype system that will consist of four video portable automotive data acquisition system for cameras, each the size of a thumb; sensors strewn crash-avoidance research (DASCAR). The goal is along the car's bottom and under the hood; and an to apply technologies developed for defense to the on-board computer system. The computer system, reduction of human suffering and financial losses which is small enough to fit in the trunk of almost resulting from vehicle collisions on U.S. any car, collects, records, processes, compresses, highways. and transmits data from the sensors and cameras. The effort is receiving U.S. Department of The processed data will be transmitted to a control Transportation (DOT) funds designated for center by cellular telephone and microwave development of the Intelligent-Vehicle Highway communications with a satellite (for cars on the

80 Oak Ridge National Laboratory REVIEW ------

"An intelligent cruzse control could be developed to respond instantly to shrinking distances between cars to avoid a potentially deadly crash. "

Schematic of Data Acquisition System Crash Avoidance Research (DASCAR) car showing its communicati on links with the central computer control station th rough (clockwise from car) cellular telephone, microwave (to and from satellite), and radio signals. open road) and by radio telemetry (for cars on a and estimated the costs of developing a DASCAR test track). system. "Sensors will record all driver actions, such as "We were asked to conceive of an unobtrusive braking, steering, turning on the wipers, and data recording system that wouldn' t be noticed by tuning the radio, as well as data on the driver, the outside world," Carter says. "We couldn' t such as heart rate and brain waves," Carter says. have a satellite dish on the car roof, gadgets "DASCAR will gather near real-time information hanging from the bumper, or a fifth wheel behind on the car' s speed, pitch, roll, yaw, lateral position the car. We will have electrodes on the driver within the Lane, and distance from cars ahead and because it is too expensive to sense driver behind. DASCAR will also record information on physiology and behavior remotely." characteristics of the road, changes in the weather, The heart of the DASCAR system will be and traffic and sign density that could affect Scientific-Atlanta's data processing unit, which driving." collects data from all the sensors and cameras. For ORNL has completed a study to determine the this system, Scientific-Atlanta also will contribute parameters and measures that should be recorded, a radio telemetry system and satellite link for two identified available state-of-the-art hardware and way communications with the INMARSAT software to record the parameters and measures, satellite. The Global Positioning System will help

Number Three, 1994 81 TECHNOLOGY TRANSFER

determine where the car is on the road and within Medical Isotope Generator its lane. In addition, the company will provide a compressed video digital storage and retrieval Licensed to California Firm system, which rapidly retrieves and integrates A new ORNL-developed device that produces an compressed video data with other digitized inexpensive radioisotope for treating patients with information for analysis and transmission by cancerous tumors, cancer-induced bone pain, or DASCAR. arthritis may become a commercial product for ORNL's role in the CRADA will be to Rhenium- hospitals by the end of the decade. incorporate hardware supplied by Scientific Through a licensing agreement, Martin Marietta 188 is Atlanta into the other components of the data Energy Systems, Inc., has granted exclusive rights expected to acquisition system. ORNL will then install and to Isotope Products Laboratories, Inc. (IPL), in calibrate the DASCAR within five vehicle types Burbank, California, to manufacture and market the play an and will evaluate and pilot test the data acquisition tungsten-188/rhenium-188 generator. The device important system. was developed by F. F. (Russ) Knapp and "Our goals are to procure, develop, test, and role in colleagues in the Nuclear Medicine Group in validate this hardware and software on a car. We ORNL's Health Sciences Research Division. treating the will put the first DASCAR system on a car driven IPL, which was founded in 1967, produces pain of bone by the director of ORNL's Robotics and Process radioisotopes used in environmental measurements, Systems Division," Carter says. "We will drive analytical instruments, and nuclear medicine. IPL's cancer. this car around the Oak Ridge area this year. In new nuclear medicine subsidiary, IPL Imaging and 1995 we will test some DASCAR systems on cars Therapeutics, Inc., will manufacture the generator on a 7 .5-mile test track in East Liberty, Ohio. and seek U.S. Food and Drug Administration Then 15 DASCAR cars will be tested by approval to market it to hospitals. volunteers throughout the nation." 'We hope to build upon the solid development Carter says ORNL also has been asked to work of Dr. Knapp's group," says Len develop software for the data processing center to Hendrickson, IPL president. "Much clinical make sense out of data sent there from all the test development work remains to be done before the cars. Such software will seek out meaningful data rhenium generator can benefit patients worldwide. from the cars, such as a significant sequence of We look forward to completing the work necessary events occurring within one second of a car crash. to bring the product to market. The rhenium It will present the data as easy-to-interpret generator is an important addition to Isotope graphics on a display screen. Products' growing line of nuclear medicine "Most vehicle crashes could be prevented if the products. Our new subsidiary will be responsible correct action were taken within a half second to a for manufacturing and marketing the product." second before the collision," Carter says. "If the The source of the tungsten-188 for the generator car can sense that it is too close to another car, it is ORNL's High Flux Isotope Reactor. As the could be programmed to take over steering and radioactive tungsten decays in the generator, it braking from the driver at a certain point to avert forms radioactive rhenium-188, which can be used the collision. DASCAR should demonstrate that a for medical treatment. "Because half of tungsten- car's lateral position in the lane and distance from 188's radioactivity disappears in 69 days," Knapp cars ahead and behind can be recorded. If so, an says, "the shelf life of the generator is at least two intelligent cruise control could be developed to months. Rhenium is constantly being supplied for respond instantly to shrinking distances between several weeks. cars to avoid a potentially deadly crash." "The radioactive rhenium produced in the ORNL research for the CRADA will be generator," he adds, "emits energetic electrons supported by $205,000 from the National called beta radiation and short bursts of light called Highway Traffic Safety Administration photons as half of its radioactivity decays in about (part of DOT). 17 hours. After injection into the patient, the

82 Oak Ridge Na tional Laboratory REVIEW distribution in the body of rhenium-188-labeled agents can be monitored with photon-sensitive cameras. More importantly, the beta radiation, which can kill cancer cells, can penetrate a third of an inch into tumor tissue, suggesting that it can be used to reduce large tumors." Researchers at the Center for Molecular Medicine and Immunology at the University of New Jersey developed a procedure for chemically linking rhenium-188 to an antibody that homes in on colon cancer cells. Studies of 12 patients with colon tumors showed the ability of this therapeutic agent to concentrate in these cells. Rhenium-188 is expected to play an important role in treating cancer induced bone pain. The rhenium can be attached to certain compounds that tend to settle in bones. "The treatment is expected to be considerably less costly than using strontium-89, rhenium-186, and other radioisotopes that are currently used to treat bone pain," Knapp says, "and studies are in progress to verify this prediction. If the rhenium-188 treatment is fo und to be less expensive, it could help reduce health care costs." Patients having cancer of the breast or prostate often experience Gamma camera image (upper panel) shows two rectus bone pain when cancer cells migrate muscle tumors in a patient's peritoneal region near the liver from the primary tumor to the obtained after intravenous administration of rhenium-188- skeleton. The cancer cells can labeled antibody. The tumors can also be seen in a penetrate tissues surrounding the computerized tomographic image (below). Courtesy of D. M. bone. It is believed that increased Goldenberg, M.D., M. Juweid, M.D., R. Sharkey, Ph.D. , and pressure on nerves in this tissue from colleagues at the Center for Molecular Medicine and both tumor cells and inflammation Immunology in Newark, New Jersey. causes bone pain. The energy of the beta radiation reduces inflammation, thus joints. According to Knapp, the energy released as relieving bone pain. the rhenium decays helps relieve the painful For treatment of arthritis, the rhenium can be swelling and inflammation of arthritic joints. attached to compounds that are injected into the "The use of radioisotopes for arthritis fluid of inflamed knees and other fluid-filled treatments is very common in Europe," Knapp

Number Three, 1994 83 says. "Such treatments are expected to be used Division evaluate the microstructure of powders more widely in the United States on an aging and wires and perform other analytical population." characterizations. For example, they will determine the sizes of crystalline grains making Superconducting Wire up the wire and the chemistry in the areas between "ORNL is the grains, known as grain boundaries. For this Technology CRADA work, they are using X-ray diffraction, helping ORNL and Oxford Superconducting thermogravimetric and differential thermal develop Technology of Carteret, New Jersey, are jointly analysis, metallography, and electron microscopy. ORNL also is engaged in developing or processes for developing technology needed to produce long lengths of bismuth-2212 wires that can carry selecting lower-cost alloys that could replace the producing useful amounts of electrical current when chilled silver now used for tapes on which the bismuth is super to low temperatures. The wires will be made of deposited. In addition, ORNL and Oxford will silver tapes coated with thick bismuth films. jointly measure wire performance such as critical conducting Superconducting films and wires of short current density, critical temperature, and wire for lengths have been fabricated, but few long wires magnetization as a function of magnetic field. The one-year CRADA is valued at $125,000; electrical that have high critical current density have been reliably reproduced. ORNL is collaborating with DOE will fund $50,000 of the project. All of the conductors industrial partners to develop reliable processes work at ORNL is funded by DOE's Office of and energy for fabricating long superconducting wires for use Energy Management's Superconductivity in bulk electrical conductors and energy storage Program for Electric Power Systems. The program storage devices. is developing with industry the technology devices." In a CRADA signed earlier this year, Oxford is necessary for commercial development of electric developing a dip-coating process for coating power applications of high-temperature silver tapes with long, thick films of bismuth. superconductors. Oxford has the primary responsibility for all Oxford Superconducting Technology is a powder and slurry preparation; for preparation, leading producer of low-temperature heat treatment, and evaluation of longer lengths superconductors used in magnets for magnetic of prototype conductors; and for actual resonance imaging (MRI) scanners, nuclear manufacturing of the wires. magnetic resonance spectroscopy, particle Oxford is choosing appropriate powders, accelerators, and other applications. The company solvents, binders, and dispersants that make has recently completed delivery of nearly two possible uniform and homogeneous coatings over million feet of superconducting cable to DOE's a long length. Oxford will also produce samples Brookhaven National Laboratory for the of dip-coated bismuth-2212 wires. Relativistic Heavy Ion Collider. ~ In the CRADA, ORNL researchers led by Robert K. Williams of the Metals and Ceramics

84 Oak Ridge National Laboratory REVIEW I Next Issue

The Oak Ridge Reservation has evolved into a valuable natural resource over the past 50 years. More than 1000 plant species and more than 300 animal species, like this young osprey nesting in the Clinch River adjacent to the reservation, now call the reservation home.