BEFORE THE
May 2, 1996
Madam Chairwoman and Members of the Subcommittee, I welcome this opportunity to discuss with you the work being done in the Physics Laboratory at the National Institute of Standards and Technology (NIST). Physics is, of course, at the very core of all physical standards and measurement, which the United States mandates as a Federal responsibility.
Consistent with this mandate, the Physics Laboratory supports U.S. industry, government and the scientific community by providing measurement services and research for electronic, optical, and radiation technology. Science and technology, once considered separate and sequential, are now becoming increasingly coupled. The work of our Laboratory thus spans the full range from programs that address the fundamental postulates of physics to those that respond to the immediate measurement needs of industry and commerce.
For example, the Physics Laboratory is responsible for maintaining and disseminating the Nation's standards of time and frequency and for coordinating them internationally.
To respond to the Nation's immediate needs, we provide a wide variety of time and frequency services including radio stations that broadcast time signals over most of the world, an Automated Computer Time Service that commodity traders, for example, can use to set the clocks on their personal computers, and a time transfer service using the Global Positioning System (GPS) satellites.
To back up these services, we have just completed a 10-year state-of-the-art engineering project and commissioned NIST-7, the most accurate atomic beam clock in the world. This standard represents a ten-fold advancement over the previous NIST standard. With this new standard, the United States regained a lead position, which it had lost to Europe shortly after the development of the first atomic clock at NBS in 1950. The performance of this clock provides NIST with a reference that is both accurate and stable enough to support rapidly advancing technology in, for example, telecommunications and navigation.
At the same time, we are pursuing research on trapped and cooled atoms aimed at developing the next generation of frequency standards, one thousand times more accurate than NIST-7. In the course of this work, we created a so-called Bose-Einstein condensate, a new state of matter that had been predicted by Bose and Einstein 70 years ago. This condensate was named "Molecule of the Year" by Science. One of our scientists, who developed many of the cooling techniques, is a member of the National Academy of Sciences and was mentioned in the write-up of the 1989 Nobel Prize for Physics. The leader of the project has already received national and international recognition for his achievement.
Why do we need a clock with one thousand times more accuracy? We can't necessarily envision all the uses, but what we do know is that for the past 50 years, the accuracy of our frequency standard has increased by a factor of 10 every seven years--and every time it increased, there was a need for it, and U.S. economic competitiveness depended on NIST to provide it. If we had waited until the need arose, we would always have been seven years behind.
Four Thrusts
Coming back to the Laboratory as a whole, we have identified four strategic areas where we believe our experience and distinctive skills best contribute to industrial requirements and critical national needs by providing measurement methods, standards, and data:
Those research and development activities upon which the measurement infrastructure of the United States depends are the constitutional responsibility of the Federal government. No other institution--public or private--performs this function for the United States. The industrial sector understands--as did the framers of our Constitution--that this must be a centrally executed responsibility, performed competently and fairly for all industry, one that must not become a competitive pawn of any one element of the private sector.
University programs, funded by NSF for example, cannot adequately support the measurement needs of the United States. Such programs are based on grants to individuals or small groups of investigators motivated, appropriately, by a combination of intellectual challenge, opportunity, and the universities' primary mission to educate future scientists. Only at NIST does the country have the mission oriented, interdisciplinary staff with the scientific weight to address the nation's most challenging measurement problems.
At NIST you will find that the same scientists who are world leaders in the longer-term fundamental research--quantum computing and Bose-Einstein Condensation, for example--are also the most eager to see their efforts amplified by applying their talents to the solution of real-world problems. We believe that the quality of our services stems in large measure from the breadth, vigor and excellence of our research programs, and that our contributions are credible only to the extent that they are based on the best technical judgment available. Thus, the Laboratory addresses the fundamental triad of standards, measurement methods, and data in a climate of vigorous and competitive research.
Examples of Accomplishments
Now I'd like to give you the flavor of some of the accomplishments of the Physics Laboratory.
Fundamental Precision Measurement:
New State of Matter
Our Laboratory was the first to demonstrate Bose-Einstein Condensation, a new form of matter originally predicted to exist by Bose and Einstein in 1924. Last July one of our young scientists cooled an assembly of rubidium atoms to a record low temperature of 10 billionths of a degree, where it condensed into what we call a single quantum state. While this could have--and has since--been done elsewhere, only at NIST is the emphasis on exploiting such a condensate to make a revolutionary new measurement device: an atom laser. An atom laser is the analog of the familiar optical laser and would allow, for example, new gyroscopes 10 billion times more accurate than our current laser gyroscopes.
Electronic and Optical Measurement and Standards:
Microlithography
Physics Laboratory scientists, in collaboration with Harvard University researchers, have demonstrated a new form of microlithography that uses neutral atoms instead of light to write patterns on silicon. The new method offers the promise of allowing integrated circuits or other microfabricated objects to be manufactured about 10 times smaller than is possible with light-based lithography methods.
Imaging Magnetic Bits
We have developed a magnetic microscope for imaging microscopic magnetic domains responsible for the performance of high density information storage devices and high efficiency power transformers. Magnetic domains can be directly imaged with atomic-scale resolution. Magnetic storage is a $30 billion per year industry, and power lost to transformer cores is estimated to be $5 billion/year. This development is the culmination of a research and development project using spin polarized electrons to study the properties of magnetic surfaces.
Atomic Clock
NIST-7, a 7th generation atomic clock developed in the Physics Laboratory at NIST over the last 10 years, has achieved an accuracy of five parts in 1015, or about 0.2 microseconds over a year's time. This clock is the basis for a wide range of time and frequency services provided by NIST. Telecommunications, navigation, stock and commodity trading, electronic networks, radio and television broadcasting, air traffic control and traffic light synchronization are a few of the many commercial activities dependent on these services.
Synchronization Helps Commuters
Los Angeles County, alone, saves an estimated 22 million gallons of gasoline every year and 55,000 hours of driving time each day by synchronizing traffic lights with our time and frequency services.
Clocks for PCs
A widely used service of the Physics Laboratory provides accurate time information in a digital format which can be used to automatically correct the time on standalone PCs, to synchronize time-clocks, and to provide time to financial institutions. The services can be accessed via dial-up telephone lines with modems and the Internet. The information is directly traceable to the primary clock ensemble maintained by the NIST Boulder Laboratories. There are now more than 70,000 time requests per day and they are increasing at the rate of 10 percent per month.
Precision Timing for Telecommunications
We helped telecommunications companies to synchronize their transmissions to provide their users error-free connections. "By my calculation, NIST saved us almost one year in the time it took to develop the proper synchronization standard," says Rodney J. Boehm, chairman of a subcommittee of the telecommunications industry's Exchange Carriers Association. "It is imperative that NIST continues to be involved to help us and ensure that we use NIST expertise to speed up the standards process for the good of the entire industry," Boehm adds.
Navigation with Global Positioning System
The Physics Laboratory played an important supportive role in the creation of the Defense Department's Global Positioning System, a satellite-based navigation network. We provided information on organizing the ground monitoring stations and analyzing time data. Even today, NIST has a contract with the operators of this system to assist in evaluating the performance of the satellites. In particular, NIST developed a method, called the Common View Method, of transmitting time and frequency information with great accuracy. This method is used--and relied upon--by high-end users, such as the Jet Propulsion Laboratory, who need very accurate timing information.
Space Communications
The Deep Space Network, which is used by NASA as its radiotelescope communications link to space flights, such as Atlantis or Apollo 13, requires the high accuracy of NIST-7 for the synchronization of transmissions utilizing the different ground stations.
Measurement and Standards for Diagnostic and Therapeutic Radiology
Mammography
Breast cancer will strike one in eight women in the U.S.A., making it the most common form of cancer among women. Approximately 46,000 women die of the disease each year. Early stage tumors, which can be detected in mammograms, are 90 to 100 percent curable. Recognizing the critical role that x-ray mammography has in early breast cancer detection, and the role of high quality physical measurements in reassuring women about the safety of mammographic procedures, Congress in 1992 passed the Mammography Quality Standards Act. The implementation of this Act has highlighted the need for improved measurement standards at NIST for two radiologic quantities, x-ray kilovoltage and radiation exposure.
Image Quality
Since mammography requires relatively low-energy x-ray beams in order to image calcifications and small tissue abnormalities, small changes in voltage yield significant changes in dose and image quality. In response to an urgent request from the Mammography Committee of the Conference of Radiation Control Program Directors, the Physics Laboratory has developed an entirely new method for measuring the voltage across these x-ray tubes -- a method based on our fundamental understanding of the behavior of x-rays, which allows us to measure their energy directly. A research grade portable instrument based on this concept will be available in June; field instruments will be generally available to calibration facilities in about a year. John Boone of the School of Medicine of the University of California, Davis, has called this "a miracle device which lets scientists measure more accurately than ever before important properties of the x-ray beam used in mammography."
Radiation Exposure
The radiation exposures in x-ray mammography must be kept to a minimum consistent with good image quality. The Food and Drug Administration is implementing the Mammography Quality Standards Act by certifying that equipment in U.S. mammography facilities is traceable to national measurement standards for radiation exposure. In response to a request from an industry group (Council on Ionizing Radiation Measurements and Standards), the Physics Laboratory in collaboration with the Center for Devices and Radiological Health at FDA, and the Medical Physics Department at the University of Wisconsin, has recently established new national standards for measuring radiation exposure and new facilities for calibrating exposure meters. The accuracy of all radiation exposure measurements in approximately 11,000 U.S. mammography facilities will trace back to the new NIST standards. You will be hearing more about this facility from Professor Paliwal.
Radiation Therapy
In addition to the x-rays used for diagnosing cancer, high energy beams of photons, electrons, protons and neutrons are used to treat the 600,000 Americans who receive radiation therapy each year. Each of these facilities relies on radiation standards developed in the Physics Laboratory to ensure that the patient receives the correct dose: too little radiation does not kill the cancer; too much kills the patient.
Standards for Prostate Cancer Treatment
Recent studies have shown that prostate cancer patients treated with radiation seed implants are just as likely to be disease free five years after treatment as men who had undergone surgery to remove the cancer--and with many fewer of the unpleasant side effects. NIST is the only laboratory in the world that now offers standards for the iodine-125 isotope used in the most common of these seed implants.
Optical Radiation Measurement and Standards
Looking Good
We provide optical standard reference materials to a broad range of U.S. manufacturers whose sales depend critically on how a product looks to the customer, e.g., automobiles, paints, plastics, clothes, toys, furniture, and packaging materials.
Photographic Film Industry
We work with and provide standards to major photographic film manufacturers to ensure that a given type of film produced in many factories throughout the world is equivalent and of consistently high quality.
Color Displays
Our optical radiation calibration services are used by companies that make and calibrate instruments used in the graphic arts fields, for example, to ensure that computer displays give accurate rendition of color.
Remote Sensing
We provide optical radiation calibration support for high priority, interagency, remote-sensing programs involving national defense, environmental monitoring, and space research. For example, our infrared standards are used in developing heat-seeking missile sensors and aviator night vision goggles. Our ultraviolet standards are used in international efforts to monitor long-term changes in the intensity of terrestrial solar ultraviolet radiation which can occur as a result of ozone layer changes--more than one million cases of skin cancer will occur this year due to exposure to harmful UV rays from the sun. Our vacuum ultraviolet and visible radiation standards were used to characterize and calibrate all the Hubble space telescope cameras.
With such a variety of measurement skills and needs, how do we decide which ones are appropriate and possible for us to take on? In each of our areas, we have different--but long established--methods for setting priorities and measuring results. All of these methods focus on understanding the needs of our customers.
In the area of optical radiation technology, we look to the Council for Optical Radiation Measurements (CORM). NIST established CORM in 1972 to determine Pressing Problems and Projected National Needs in Optical Radiation Measurement. CORM is a nonprofit organization composed of individual members from industry, government and academe interested in the measurement of optical radiation. About 150 U.S. companies are represented by CORM. CORM's aim is to establish a consensus among interested parties on industrial and academic requirements for physical standards, calibration services, and interlaboratory collaboration programs in the field of optical radiation measurements. This includes setting priorities, liaison with NIST, dissemination of information, response to inquiries, and cooperation with other organizations. CORM's sixth report of Pressing Problems and Projected National Needs in Optical Radiation Measurements came out last December.
Because CORM has been so effective in helping us set priorities for optical radiation measurement, in 1993 we established a similar organization representing thousands of users of ionizing radiation, the Council for Ionizing Radiation Measurements and Standards (CIRMS). CIRMS has now published its first report on National Needs in Ionizing Radiation Measurements. Such radiation includes high energy ultraviolet light, x-rays, gamma rays, and energetic particles including electrons, protons and neutrons. Technological applications include diagnostic and therapeutic radiology, radioisotope imaging, radiation protection and radiation processing.
For our third service-oriented division, Time and Frequency, we use a different approach to setting priorities because of the different nature of our constituency. Here we receive about 6000 calls and 3500 written inquiries a year. And in addition to our direct one-on-one contact with customers, we interact closely with the manufacturers of devices dependent on our services, who in turn interact with the customers. So we have two routes for finding out about customers' concerns and needs. We also use periodic surveys, which we publish in the magazines and journals that our customers are likely to read. These surveys provide important confirmation of what we've been hearing all along--and also more quantitative information on who is interested in what services. In the last survey, we had 6000 responses to what was a detailed and demanding questionnaire.
So if we work closely with our customers in setting priorities for our service-oriented programs, how do we decide on our longer term programs of fundamental research? For any scientist and scientific institution, this is a continuous process. For NIST the basic question is, "Do our research programs meet the present and future measurement needs of the United States?" One way our scientists attempt to answer this question is by attending meetings held by professional societies, identifying the most exciting or relevant projects, and then deciding whether the ideas generated by this process can compete with research programs already in place or being planned at NIST.
Measuring Results
As with setting priorities, we look to our councils (CORM and CIRMS), our surveys, and our many interactions with industry for feedback on how we are performing our jobs.
As a recent experiment in the Physics Laboratory, we have initiated several economic impact studies. The most comprehensive are those performed by independent contracted researchers who examine rates of return realized from investment in a given type of technology and in different stages of the technology's development by measuring and quantifying the economic returns from our research and services. In these studies, the rate of return is computed in the same way that rates of return are calculated from the time flows of costs and benefits associated with a particular project or investment in the business and financial communities. The results provide another perspective on the value that U.S. taxpayers realize from their investment in our programs. A recent study on the economic impact of the Spectral Irradiance Standard indicated that the social rate of return is 145 percent. This rate is higher than that reported in recent studies on private-sector R&D investments and academic research.
Because much of our fundamental science is designed to anticipate the Nation's measurement needs, the central issue in assessing it lies in defining the goal against which progress is to be measured. Leadership across the frontiers of scientific knowledge is at the heart of that goal. It assures that American scientists are expanding the knowledge base at the leading edge. Merit review based on peer evaluation continues to be the primary vehicle for assessing excellence and leadership of fundamental science programs. Accordingly, the significance of the Laboratory's contributions is assessed by prestigious awards, publication of results in prestigious journals, and invitations to present talks at prestigious national and international conferences. For example, the significance of the Laboratory's contributions has been acknowledged by receipt of almost every prize (often more than once) in atomic, molecular and optical physics awarded by the relevant professional societies. Three of our scientists are members of the National Academy. One was cited in the 1989 Nobel Prize for Physics. Another received a standing ovation at an international conference this past summer for the first demonstration of Bose-Einstein Condensation.
In addition, all of the technical programs of the Physics Laboratory are reviewed annually by external panels convened by the National Research Council. The panels consist of scientists, engineers and technical managers from academia, industry and government. They assess the technical quality and effectiveness of our programs, our priorities and priority setting process, and our impact on industry and how this impact is measured. This process for evaluating our programs has, with some modifications, been used effectively for 37 years.
I hope that I have given you some sense of the research we do in the Physics Laboratory both to respond to the Nation's immediate measurement needs and to anticipate its future needs. I hope, too, that I have made it clear why we need a cadre of the world's leading scientists to tackle the measurement challenges that no company or industry or university department could possibly undertake.
I will be happy to answer any questions you may have.
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Online: Jun 11 1996
