5

Physics Laboratory



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 105
An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES: Fiscal Year 2000 5 Physics Laboratory

OCR for page 105
An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES: Fiscal Year 2000 PANEL MEMBERS David H. Auston, Case Western Reserve University, Chair Janet S. Fender, Air Force Research Laboratory, Vice Chair Anthony J. Berejka, Consultant, Huntington, New York Gary C. Bjorklund, Bjorklund Consulting, Inc. D. Keith Bowen, Bede Scientific Incorporated Shirley Chiang, University of California, Davis Gregory R. Choppin, Florida State University Leonard S. Cutler, Agilent Technologies Ronald O. Daubach, OSRAM SYLVANIA Development, Inc. Paul M. DeLuca, Jr., University of Wisconsin Medical School Jay M. Eastman, Lucid, Inc. Stephen D. Fantone, Optikos Corporation Thomas F. Gallagher, University of Virginia Daniel J. Larson, Pennsylvania State University David S. Leckrone, NASA Goddard Space Flight Center Neville V. Smith, Lawrence Berkeley National Laboratory Submitted for the panel by its Chair, David H. Auston, and its Vice Chair, Janet S. Fender, this assessment of the fiscal year 2000 activities of the Physics Laboratory is based on site visits by individual panel members, a formal meeting of the panel on March 13-14, 2000, in Gaithersburg, Md., and on documents provided by the laboratory.1 1   U.S. Department of Commerce, Technology Administration, National Institute of Standards and Technology, Physics Laboratory: Technical Activities 1999, NISTIR 6438, National Institute of Standards and Technology, Gaithersburg, Md., 2000.

OCR for page 105
An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES: Fiscal Year 2000 LABORATORY-LEVEL REVIEW Laboratory Mission According to the laboratory documentation, the mission of the NIST Physics Laboratory (PL) is to support U.S. industry, government, and academia by providing measurement services and research for electronic, optical, and ionizing radiation technology. This mission is appropriate to the overall mission of NIST, and the areas of research specified in the PL mission are appropriate to the core competencies of the laboratory. The PL strives to meet its mission through the programs and ongoing projects in its six divisions: Electron and Optical Physics, Atomic Physics, Optical Technology, Ionizing Radiation, Time and Frequency, and Quantum Physics. The first five of these divisions are reviewed by the panel below. The Quantum Physics Division, which is part of JILA, a joint institute of NIST and the University of Colorado, is assessed by a separate subpanel in the final section of this chapter. The panel notes that NIST's role in measurement and standards for use in commerce is unique and cannot be duplicated by industry or academia. To the extent that the PL continues to focus its activities on this core mission of measurement and standards, it can be assured that its programs will be appropriate to NIST. Technical Merit and Appropriateness of Work Overall, the technical merit of ongoing programs and projects in the PL is very high. Many projects are at or define the state of the art, and in some cases, NIST is not just the leader but the dominant force in highly competitive areas of scientific research. Detailed descriptions and assessment of ongoing programs are given in the divisional reviews below. The panel was briefed by PL personnel on four areas of new or expanding opportunity for the PL: nanotechnology, biophysics, medical physics, and quantum information. In nanotechnology, the PL is already a world leader in the fabrication and analysis of small structures such as thin magnetic layers. Future plans include better understanding of edge effects in small magnetic and electronic structures and of electron transport and tunneling in ferromagnetic, semiconductor, and superconductor materials. This work would be complementary to ongoing work in other NIST laboratories on single-electron tunneling devices, nanoscale metrology, nanoscale analysis, and other areas. In biophysics, many PL measurement techniques can be adapted to provide new measurement capabilities for the biological sciences. For example, great potential exists for the use of laser light to isolate and manipulate biological objects such as proteins or enzymes. This opportunity is enhanced by the growing presence of biotechnology firms near Gaithersburg, Maryland, which provides PL with potential partners for its work and a critical mass of interested researchers in the immediate area. In medical physics, the aging of the baby boom generation will bring greater need for medical diagnostics, treatment, and palliative therapies. It is anticipated that many new techniques involving ionizing radiation, such as the recent introduction of radioactive seed therapy for prostate cancer, will be developed. These will require new standards and measurement techniques to ensure the quality of treatment delivered. New programs would build on the PL's current status as provider of primary standards for the medical use of ionizing radiation. Quantum information is a highly speculative but potentially high-payoff project that uses NIST's unquestioned world leadership in the manipulation of atoms and atomic states to explore one promising avenue toward quantum computing. Although achieving useful computational ability based on the use

OCR for page 105
An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES: Fiscal Year 2000 of quantum states to store information is an as-yet-uncertain proposition, it is an understatement to say that, if realized, its impact would be profound. Early exploratory research such as this could give the United States a definitive lead in the development and use of such technology. The talent engaged in this effort at NIST is extraordinary and bodes well for important advances. The panel was highly impressed by the content of all four of these presentations. All represent areas with great potential for economic importance, and all four are areas in which an existing PL expertise base can be built upon to establish new areas of leadership. Most are highly interdisciplinary in nature and will leverage scientific expertise available in other NIST laboratories to achieve accomplishments that would not be realized by any one laboratory alone. These four directions represent appropriate avenues to explore and pursue as PL tries to anticipate future developments so that measurement and standards technologies can be available when industry requires them. Impact of Programs The results of PL programs are disseminated widely through various means, such as professional publications, seminars, workshops, and the World Wide Web. The degree to which researchers and programs are tied to their eventual industrial customers varies with the nature of each program, as is appropriate. PL management and staff must continually work to maintain and strengthen ties to industry in such a way as to truly ascertain industry's anticipated needs rather than react to current industry wants. Several programs discussed—for example, Internet time service and quantum information—raised questions of how intellectual property was handled by PL and NIST in instances that might generate significant direct economic value. Although a certain amount of case-by-case decision making will always be necessary in this area, the current policy seemed a bit too ad hoc. The panel encourages PL and NIST as a whole to develop a better planned, more-thought-out, and more consistent approach to intellectual property management. In the two examples mentioned above, the potential revenue streams might not be insignificant, and thought must be given to an approach to intellectual property that not only is equitable but also provides incentives both to PL and to the individual investigator to pursue intellectual property protection appropriately. Laboratory Resources Funding sources for the Physics Laboratory are shown in Table 5.1. As of January 2000, staffing for the Physics Laboratory included 200 full-time permanent positions, of which 168 were for technical professionals. There were also 56 nonpermanent and supplemental personnel, such as postdoctoral research associates and part-time workers. The pool of scientific talent collected in the laboratory is outstanding by any measure, and a number of staff members are simply unequaled anywhere in their expertise. The panel was particularly pleased to see that the PL is able to recruit and (thus far) retain young researchers of very high quality—a promising development for the future of NIST and the PL. Although notable progress has been made on facilities needs in some areas, significant capital equipment and facility needs noted in previous reports are still outstanding. Like many other government laboratories, NIST has historically underinvested in facility maintenance and upgrade, and the PL has no long-term plan for capital equipment purchases. Such deficiencies can seriously compromise the PL's ability to compete in recruiting and retaining the most talented scientists. Since its outstanding staff are PL's and NIST's greatest resource, this would gravely affect NIST's ability to carry out its mission. Specific facility and equipment needs are detailed in the divisional reports below.

OCR for page 105
An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES: Fiscal Year 2000 TABLE 5.1 Sources of Funding for the Physics Laboratory (in millions of dollars), FY 1997 to FY 2000 Source of Funding Fiscal Year 1997 (actual) Fiscal Year 1998 (actual) Fiscal Year 1999 (actual) Fiscal Year 2000 (estimated) NIST-STRS, excluding Competence 29.8 31.2 33.0 32.9 Competence 2.9 1.9 1.6 1.8 ATP 0.8 1.8 1.9 2.2 Measurement Services (SRM production) 0.3 0.2 0.2 0.1 OA/NFG/CRADA 9.6 9.5 10.1 11.6 Other Reimbursable 3.4 3.5 3.6 3.8 Total 46.8 48.1 50.4 52.4 Full-time permanent staff (total)a 206 207 204 200 NOTE: Funding for the NIST Measurement and Standards Laboratories comes from a variety of sources. The laboratories receive appropriations from Congress, known as Scientific and Technical Research and Services (STRS) funding. Competence funding also comes from NIST's congressional appropriations but is allocated by the NIST director's office in multiyear grants for projects that advance NIST's capabilities in new and emerging areas of measurement science. Advanced Technology Program (ATP) funding reflects support from NIST's ATP for work done at the NIST laboratories in collaboration with or in support of ATP projects. Funding to support production of Standard Reference Materials (SRMs) is tied to the use of such products and is classified as Measurement Services. NIST laboratories also receive funding through grants or contracts from other government agencies (OA), from nonfederal government (NFG) agencies, and from industry in the form of Cooperative Research and Development Agreements (CRADAs). All other laboratory funding, including that for Calibration Services, is grouped under “Other Reimbursable.” a The number of full-time permanent staff is as of January of that fiscal year. As noted above in “Technical Merit and Appropriateness of Work,” the PL has identified several research areas for new programs that the panel believes represent great opportunities for NIST and potentially great contributions to emerging industries and areas of national priority. However, success in establishing a NIST presence in these areas will require substantial resources to build up necessary infrastructure and expertise. Reprogramming can and should be used to obtain resources for these areas, but reprogramming alone cannot provide the level of investment necessary to begin ambitious new programs such as these. New funding is required to begin adequate programs in these areas. More aggressive advocacy for new funding for the PL, and for the Measurement and Standards Laboratories as a whole, seems appropriate. DIVISIONAL REVIEWS Electron and Optical Physics Division Division Mission According to division documentation, the mission of the Electron and Optical Physics Division is to develop measurement capabilities needed by emerging electronic and optical technologies, particularly those required for submicron fabrication and analysis.

OCR for page 105
An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES: Fiscal Year 2000 Technical Merit and Appropriateness of Work The Electron and Optical Physics Division is organized into three groups: the Photon Physics Group, the Far Ultraviolet Physics Group, and the Electron Physics Group. All three groups do world-class work in their respective fields. This work is generally consistent with the NIST mission and national needs in the areas of nanoscience and nanotechnology. The work spans the range from basic theory of magnetism and Bose-Einstein condensates to calibration of multilayers and detectors for industry and for the National Aeronautics and Space Administration (NASA). The division provides the central national basis for absolute radiometry in the deep-ultraviolet (DUV) and extreme-ultraviolet (EUV) regions of the electromagnetic spectrum, which together span the photon energy range from 5 to 250 eV. The Photon Physics Group, in collaboration with the Optical Technology Division, has developed state-of-the-art measurement capability for characterizing the optical properties of materials in the DUV. This region of the spectrum has always been difficult, since almost all materials absorb this radiation. Thus, there are few suitable refractive materials for wavelengths less than 180 nm, there is a lack of continuous-wave lasers, deleterious optical damage occurs, and there is no laboratory-sized true continuum source available for the entire region. The division is now able to provide DUV transmission and index-of-refraction data on optical materials such as calcium fluoride (CaF2) that are critical to 157-nm lithography. The accuracy (6 ppm) of these measurements of index of refraction matches the stringent requirements for stepper design and has revealed unacceptable supplier-to-supplier index variation in the CaF2. In addition, using the Synchrotron Ultraviolet Radiation Facility (SURF III) the group has developed a new radiometric source calculable to a precision better than 1 percent for all wavelengths greater than 2 nm. Together with absolute cryogenic radiometer (ACR) measurements, a new, improved radiometric source has been achieved in the DUV with an uncertainty of less than 1 percent. Work is also being conducted on the development of damage-resistant, solid-state DUV detectors. The Photon Physics Group's EUV physics programs are well focused in important directions. The program in EUV optics continues to be of considerable value for the future of the semiconductor industry, given the increasing likelihood that EUV lithography will become a critical technology in this industry in the future. Progress toward making high-reflectivity multilayer films with reflectivity peak matched to the 10.5-nm wavelength of the new krypton (Kr) laser plasma source is significant. Current activities include building up rare-gas cluster and laser plasma sources for pulsed EUV dosimetry and the installation of an ion beam deposition machine for improved-quality EUV mirror coatings. The program in x-ray microtomography of integrated circuits has the long-term promise of providing three-dimensional maps of the elemental and chemical composition of integrated circuits and other small engineered structures. Industrial interest has been expressed by DEC, Intel, and IBM. In the first experiments, submicron resolution was demonstrated on an as-grown integrated circuit interconnect using the advanced photon source (APS) synchrotron radiation ring at Argonne National Laboratory. Recently, work using improved reconstruction algorithms has resulted in improvement by a factor of 2 in image resolution. Another planned improvement is the use of a scintillator combined with 10× optical magnification before the charge-coupled device (CCD) detector array. Although these experiments currently require synchrotron radiation, it is possible that laser plasma x-ray sources could be used in the future. The Far Ultraviolet Physics Group has completed the upgrade of SURF II to SURF III and reinstalled several beam lines. Key operations are back online, and daily service to internal and external customers has been resumed. The energy of the electron beam has been successfully increased from 284 to 331 MeV, and eventual operation at 405 MeV is anticipated. A primary goal of this upgrade is to

OCR for page 105
An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES: Fiscal Year 2000 provide the world's leading standard of irradiance in the DUV and EUV regions of the spectrum, and this goal is being realized. Calibration and standards services are being provided using an array of beam lines: one is being used for the determination of reflectivities of multilayer optics and related investigations; another is supporting NASA programs in solar physics and EUV astronomy; a third is being used for the ultraviolet (UV) and EUV detector transfer standards program; and a fourth has been equipped with an EUV conversion microscope for EUV lithography mask inspection. The unusual geometry of the SURF ring permits collection of data over a large solid angle, which could make the ring a highly competitive, if not world-leading, source of synchrotron infrared (IR) radiation. The group is urged to do nothing that would preclude such a development in the future. Long-term issues for the facility include boosting the customer base and renewing the staff. By customary metrics (e.g., numbers of users and publications), SURF is already among the most cost-effective synchrotron facilities in the United States. If the number of users can be brought up to full complement, SURF should move into the lead for cost-effectiveness. The Electron Physics Group is a world leader in the fabrication and analysis of small structures, particularly those involving thin magnetic layers. Polarized neutron reflectivity and scanning electron microscopy with polarization analysis (SEMPA) were used to reveal magnetic domain structures and layer-by-layer alignment of magnetization responsible for giant magnetoresistance (GMR) in cobalt-copper (Co-Cu) multilayers. A scanning tunneling microscope (STM) was used to study manganese (Mn) growth on iron Fe(001), with implications for models of biquadratic coupling in Fe-Mn-Fe(001) from SEMPA data. A magneto-optical trap was demonstrated for chromium, as a first step for possible creation of a monochromatic, coherent source of Cr atoms for novel deposition studies. Theoretical models were developed for spin-polarized light emission in scanning tunneling microscopy for the temperature dependence of exchange bias effects, for magnetic hysteresis in ultrathin films, and for electrical conductivity of GMR in thin film systems to test the validity of the relaxation time approximation. The group has recently decommissioned its two older SEMPA instruments and is eagerly awaiting the arrival of a new field emission scanning electron microscope, which will be combined with its best, NIST-built, electron spin polarization analyzers. The resulting new SEMPA instrument will permit sub-10-nm resolution with improved spin analyzer sensitivity and instrument reliability. The group has completed assembly of the new Nanoscale Physics Facility. This facility is centered on the measurement capability of a cryogenic, ultrahigh-vacuum STM that will operate at temperatures as low as 2 K with the ability to apply magnetic fields of varying orientation up to 1.5 T, or a fixed orientation field up to 10 T. The facility has two molecular beam epitaxy chambers, one for metal deposition and one for semiconductor III-V materials deposition, with in situ transfer of fabricated samples among the chambers. The facility will be used to probe the underlying physics in quantum confined structures on the nanometer-length scale. Software has already been developed to perform the atom-by-atom assembly of desired, complex nanostructures under completely autonomous computer control. The first experimental results from this facility are expected shortly. Impact of Programs The overall program of the Electron and Optical Physics Division is responsive to industry needs in high-density magnetic storage and devices, higher-density circuitry for electronic devices, and enhanced accuracy and accessibility of optical and radiometric metrology. All three groups within the division are in very strong positions to contribute to the National Nanotechnology Initiative proposed in the Administration's fiscal year 2001 budget. The work of the Electron Physics Group in characterization of

OCR for page 105
An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES: Fiscal Year 2000 TABLE 5.2 Sources of Funding for the Electron and Optical Physics Division (in millions of dollars), FY 1997 to FY 2000 Source of Funding Fiscal Year 1997 (actual) Fiscal Year 1998 (actual) Fiscal Year 1999 (actual) Fiscal Year 2000 (estimated) NIST-STRS, excluding Competence 4.7 4.6 5.0 5.4 ATP 0.1 0.2 0.2 0.1 OA/NFG/CRADA 0.8 0.5 0.6 0.7 Other Reimbursable 0.1 0.1 0.1 0.1 Total 5.7 5.4 5.9 6.3 Full-time permanent staff (total)a 27 27 23 23 NOTE: Sources of funding are as described in the note accompanying Table 5.1. a The number of full-time permanent staff is as of January of that fiscal year. magnetic thin films and fabrication of nanometer-scale structures is extremely important to U.S. industry in magnetic storage technology and next-generation integrated circuit manufacturing and is also completely in accordance with the division, laboratory, and NIST missions. Industrial collaborations in this area were noted in the technical merit section above. In view of the strong candidacy of EUV lithography as a likely successor technology in the manufacture of microelectronics, there is no doubt that the activities of the Photon Physics Group and SURF III and its calibration and standards capabilities constitute a key part of the national capability. Division Resources Funding sources for the Electron and Optical Physics Division are shown in Table 5.2. As of January 2000, staffing for the Electron and Optical Physics Division included 23 full-time permanent positions, of which 20 were for technical professionals. There were also three nonpermanent and supplemental personnel, such as postdoctoral research associates and part-time workers. The staff characterizes repairs to the Radiation Physics Building as adequate. The procurement process was criticized as being inflexible, with the $2,500 threshold for competitive bidding thought to be too low. In light of the large recent capital investment in equipment, the panel's concerns about the funding now shift to providing adequate resources for the proper operation and staffing of the facilities. Atomic Physics Division Division Mission According to division documentation, the mission of the Atomic Physics Division is to carry out a broad range of experimental and theoretical research in atomic physics in support of emerging technologies, industrial needs, and national science programs.

OCR for page 105
An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES: Fiscal Year 2000 Technical Merit and Appropriateness of Work The Atomic Physics Division is organized into five groups: Atomic Spectroscopy, Quantum Processes, Plasma Radiation, Laser Cooling and Trapping, and Quantum Metrology. The division is the nation' s premier source for atomic data such as atomic energy levels, transition probabilities, and transition wavelengths. This work is primarily carried out by the Atomic Spectroscopy Group. The Atomic Data Center achieved a major milestone in the past year with the inauguration of its second-generation, more sophisticated, Web-based data archive. Additional improvements have already been incorporated into the Web site since its introduction in direct response to customer feedback. This high degree of responsiveness is applauded by the panel. This Web site has approximately 150,000 hits per month from commercial, academic, government, and international users. The division also completed the first major revision in 13 years of the compilation of fundamental constants. The new compilation is now Web-based and receives approximately 150,000 requests per month. Another major achievement of the Atomic Spectroscopy Group during the past year is the first accurate measurement of the spectrum and wavelengths of the components of the 157-nm laser transition of molecular fluorine. Last year the group obtained the first accurate measurement of the index of refraction of calcium fluoride at this wavelength. Accurate knowledge of these parameters is essential to the photolithography technology for the next generation of densely packed large-scale integrated devices. There is little doubt that this work will contribute significantly to the future profitability of the U.S. microchip industry. Very important theoretical work in atomic and molecular physics is continuing in the Quantum Processes Group. A new initiative is under way to calculate the next generation of relativistic wave functions using nonorthogonal orbitals for use in ab initio computation of atomic structure. This is in response to the identification of a major source of systematic error in the current single and multi-configuration Dirac-Fock codes—the inadvertent mixing of Russell-Saunders coupling (LS) and jj (electron angular momentum) coupling. Another noteworthy theoretical achievement is the development of a simple algorithm to calculate the electron collision ionization cross sections for a wide array of molecules. The algorithm reproduces experimental cross sections to better than 20 percent for all molecules for which experimental values exist. This will be a very useful and widely applicable tool that provides a simple means of disseminating NIST expertise to applications such as atmospheric science or low-temperature processing of plasmas. The launch of NASA's Chandra X-ray Observatory during the past year raises both an important challenge and an opportunity for NIST. Astrophysicists acquiring medium-energy x-ray spectra with Chandra are faced with a lack of accurate atomic data for high-ionization stages of many elements. These data are needed for the theoretical modeling of the cosmic phenomena being observed, which was unknown before the launch but is immediately evident from the observations. Astrophysicists now face the prospect of trying to extract science from these very valuable data with an inadequate set of basic atomic data. An analogous situation was faced in 1990 by ultraviolet spectroscopists contemplating the millions of UV transitions of low ionization stages across the periodic table, as the Hubble Space Telescope (HST) and its high-resolution ultraviolet spectrograph were being launched. In the 1990s, NIST atomic spectroscopists joined with others around the world to dramatically upgrade the atomic database needed to interpret the HST observations. The nation has invested billions of dollars in these space missions to acquire astrophysical data of high precision. The Physics Laboratory has the facilities and expertise to make a great contribution to solving this problem via x-ray spectroscopy and its electron beam ion trap (EBIT), which can form an excellent analogue of conditions inside an expanding supernova remnant. Since Chandra has a lifetime of 5 to 10 years and is in too high an orbit for maintenance

OCR for page 105
An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES: Fiscal Year 2000 by a space shuttle, new data are needed quickly. The Quantum Metrology Group has taken up this challenge with enthusiasm, and the panel welcomes this move. The panel also encourages NIST staff to initiate collaborations with the community of astrophysicists using Chandra. The Quantum Metrology Group has also begun an important collaboration with the National Institutes of Health and the Research Collaboratory for Structural Bioinformatics, the group responsible for the Protein Data Bank, to design methods for rapidly identifying protein fragments through x-ray powder diffraction. This effort combines simulating patterns directly from the database and a rapid means of data acquisition. The division is also participating in an interlaboratory Competence project in length metrology. Progress on this project has been excellent. The division has constructed a laser system for displacement metrology in which the absolute accuracy of an iodine-stabilized laser is transferred to a bank of “flywheel” lasers with higher power and greater short-term stability. The flywheel lasers then exhibit the accuracy of the iodine-stabilized laser over both short and long timescales, an important achievement crucial to achieving real-time interferometric measurements for active servo control. The division has also designed and built a facility for prototyping interferometers. A two-stage passive vibration isolation system in conjunction with a specially designed vacuum chamber provides vibration isolation superior to any other system in use at NIST. The Laser Cooling and Trapping Group continues to be a world leader, mostly owing to its forefront work with Bose-Einstein condensates (BECs). In the past year the group has made two significant advances. The first is the development of a Raman technique for ejecting coherent beams of atoms from BECs, one that offers a substantial advantage over previous approaches to such an “atom laser,” all of which relied on gravity to accelerate the atom beam. In the NIST system the atoms are ejected with a high enough velocity that the resulting beam does not spread due to interatomic forces. The second advance is the characterization and control of the quantum phase of the BEC. NIST researchers have measured the spatial variation of the quantum phase and shown that its uniformity is destroyed by releasing the condensate, because the interatomic interactions are converted to kinetic energy. They have also demonstrated their ability to write a phase variation on the condensate and have used this to do several fascinating experiments. The most spectacular is writing the phase variation onto the condensate so as to create a soliton, a solitary wave that propagates in a nonlinear medium at a speed slower than the speed of sound. The condensate is a nonlinear medium due to the interactions between its atoms. The experiments to characterize the phase of the condensate and modify it represent an example of the collaborative efforts of the Laser Cooling and Trapping Group and the BEC Theory Program in the Electron and Optical Physics Division. In fact, the cooperation between these groups is quite broad. They have worked together on several important aspects of laser cooling, such as the effects of scattering resonances and photoassociation spectroscopy. This true collaboration has made NIST one of the world centers for both experimental and theoretical cold atom research. The experimental activities of the Plasma Radiation Group span an enormous range, from studies of the low-temperature plasmas used commercially to manufacture semiconductor devices to studies of the properties of highly charged ions relevant to fusion or astrophysical plasmas. Using the EBIT, one of few such apparatuses in the world, the group has been exploring the use of highly charged ions for lithography. Conventional ion beam etching relies on the kinetic energy of the ions. A highly charged ion beam can provide not only the kinetic energy but also the coulomb energy that is released when the highly charged ions capture electrons from the substrate. The effects of the highly charged ion beam are localized at or near the surface of the substrate, and to ensure that it is not examining the effects of exposure to the atmosphere subsequent to exposure to the ion beam, the group has recently incorporated a high-vacuum STM into its target chamber. This allows in situ analysis of samples subsequent to ion

OCR for page 105
An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES: Fiscal Year 2000 bombardment. Recently the group observed the effect of bombarding graphite surfaces with Xe44+ ions. Protrusions rather than craters occur where the ions hit the surface. These results indicate that the highly stripped ions have penetrated below the surface of the graphite and removed electrons from nearby carbon atoms, creating a coulomb explosion of the resulting carbon ions, which pushes up the surface of the graphite. Impact of Programs Interactions between atoms now limit the cesium fountain as a time standard. Further improvement of the time standard requires a better understanding of how dense samples of cold atoms behave. It is impossible to foresee all of the phenomena that will affect an improved time standard, so in the long run the most efficient approach is to study cold atoms in a broad way. NIST is doing precisely this in its ongoing research on a cesium atomic fountain frequency standard, Bose-Einstein condensation, photo-association spectroscopy, and ultracold plasmas. The future potential for quantum computing using condensate atoms in an optical lattice poses many challenges and is most exciting because it may offer the possibility of many qubits of computing power. The Laser Cooling and Trapping Group is actively pursuing these possibilities, in parallel with the ion trap effort of the Time and Frequency Group. The impact of the new program on rapid protein identification will be primarily in drug design and medical diagnosis. This is an example of fruitful interlaboratory cooperation. The long-standing program on x-ray metrology for the semiconductor industry is now making an impact, with the realization that such methods are needed for the generation of very thin films such as high-permitivity gate dielectrics. Physics Laboratory expertise will be used in the coming year to prepare and calibrate new Standard Reference Materials for the semiconductor industry, in collaboration with the Materials Science and Engineering Laboratory. The impact of the newly revised fundamental constants appears to be strong. The fundamental constants database is accessed about 250,000 times a month, and the more specialized atomic spectroscopy database is accessed 150,000 times per month. About a third of these requests are from U.S. industry, showing that NIST is fulfilling its role of disseminating its information to this major stakeholder. The ability of NIST to contribute to the interpretation and utilization of data from the Chandra will also have a major impact on the U.S. astrophysics program. Division Resources Funding sources for the Atomic Physics Division are shown in Table 5.3. As of January 2000, staffing for the Atomic Physics Division included 31 full-time permanent positions, of which 26 were for technical professionals. There were also 14 nonpermanent and supplemental personnel, such as postdoctoral research associates and part-time workers. The panel is extremely pleased to note that the PL management has made a strong commitment to the future of atomic spectroscopy. The Atomic Spectroscopy Group within NIST's Physics Laboratory remains the preeminent organization in the world for the acquisition, systematic evaluation, and archiving of fundamental atomic data. Many commercial, academic, and government organizations depend on this group as the primary source of comprehensive and accurate atomic data—wavelengths, atomic energy levels, transition probabilities, line-broadening parameters, hyperfine structure, isotopic shifts, and other data. In last year 's report the panel expressed considerable alarm that this group was on a

OCR for page 105
An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES: Fiscal Year 2000 fundamental measurement techniques continues to produce new results of importance both to fundamental science research and to evolving industries. As highlighted above, a recent breakthrough at JILA enables stabilized optical frequencies to be linked with radio-frequency time standards in a single step, a development that should revolutionize precision optical standards and measurements that are of importance for emerging telecommunications industries. JILA, long a world leader in the stabilization of lasers, recently locked a Nd:YAG (neo-dynium:yttrium-aluminum-garnet) laser to a narrow molecular line of iodine with world-record stability. The breakthrough came by combining this technology with new JILA expertise in nonlinear optical physics, discussed in the next section. This work was supported by NIST Competence funding. JILA made news 2 years ago with its precise measurement of atomic cesium parity violation, which probes for new physics beyond the electroweak standard model. Since that time, JILA measurements of Stark shifts in cesium have helped to show that the atomic theory of cesium may be more accurate than previously thought, with a smaller error in the calculation of parity violation. Using the smaller uncertainty, there appears to be a significant deviation between atomic parity violation and the electro-weak standard model. This has important implications for elementary particle physics. Other admirable advances in fundamental measurement techniques have been made since the last assessment. For example, a new type of far-off-resonance dipole trap for cold atoms that uses circularly polarized light has been successfully demonstrated, with possible applications to new measurements of parity violation. Cavity-enhanced optical absorption methods have been improved as a way to detect tiny absorption by molecular overtone lines or trace quantities of atoms and molecules. Two gravity projects have recently produced results, one yielding a compact instrument for field-portable absolute-g measurements, the other producing a dedicated apparatus to measure the Newtonian gravitational constant (G) and help resolve large discrepancies between published determinations of this fundamental quantity. Optical and Nonlinear Optical Physics The success of several recent experiments in the ultrafast regime has placed JILA at the forefront of optical physics and nonlinear optics. Significant contributions have been made to advancing spatiotemporal coupling in nonlinear pulse propagation, with connections to continuum generation and telecommunications; phase stabilization of mode-locked lasers, with applications to precision measurement; and generation of high-harmonic radiation, with applications to materials science and biophysics. Recent hires in this area greatly enhance the nonlinear optics effort at JILA and promise to sustain the visibility of the research and educational programs. Two examples of outstanding work in optical and nonlinear optical physics are given below. The development of the first stabilized multiterahertz frequency comb by a collaboration of JILA expertise in laser stabilization methods and precision time measurement, as described in the highlights above, promises a new era in precision measurement and immediate applications to frequency standards and to atomic spectroscopy across a broad range of wavelengths. An integral part of this success was a specific application of nonlinear optics. The standard method of frequency calibration relies on a comparison of the spectrum of second-harmonic radiation with the fundamental from which it is generated. The team used a novel photonic crystal fiber from Lucent Technologies to generate a broad continuum of radiation from a relatively narrowband input (at least by ultrafast laser standards). The continuum is generated by four-wave mixing in the fiber, which is properly phase matched at a nominal wavelength of 800 nm by virtue of the anomalous dispersive properties of the fiber. This continuum extends as far as the second-harmonic spectrum of the input, allowing a direct comparison of the extended frequency comb of the continuum-enhanced fundamental with its second harmonic. By

OCR for page 105
An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES: Fiscal Year 2000 nulling the beat note between neighboring modes in the two spectra, the frequency offset of the fundamental can be set to zero, meaning that the absolute phase of the pulses in the train output of the mode-locked oscillator is automatically zero. Stabilization of the cavity period to a timing signal derived from an atomic clock guarantees that the beat note fluctuations do not arise from drifts in the cavity length, so that a separate feedback loop adding a frequency-dependent length to the cavity can be used to control the absolute phase. This makes the entire system quite simple and robust and provides a broadband source referenced to a clock standard. This feat could not have been accomplished without the colocation of experts in ultrafast lasers, nonlinear optics, laser stabilization, and precision timing. JILA is virtually the only place in the United States, and one of only a handful of places in the world, where such groundbreaking work could happen. Such synergy is a hallmark of JILA science, and the subpanel is heartened to see it strong and vital. This accomplishment will also impact other nonlinear optics research within JILA. For instance, several recent calculations indicate that the absolute phase of an ultrashort optical pulse (the relative time at which the peak of the envelope and the nearest peak of the carrier pattern are maximum) will play a central role in determining the ionization dynamics of atoms and molecules and therefore possibly in determining the efficiency of x-ray generation. This is something ideally suited for exploration at JILA, because two of the world 's experts in x-ray generation are located in laboratories adjacent to the stabilized optical frequency standard experiment. JILA's two recent hires in x-ray generation have quickly moved to set up new facilities and are already making significant progress in the generation of vacuum ultraviolet and extreme ultraviolet (EUV) radiation. Of particular note is their demonstration of a novel coherent control method for engineering the spectrum of x-ray wavelengths generated by the photoionization of noble gases in capillaries. This method, in which details of the temporal shape (and phase) of very short pulses may be manipulated in order to optimize as few as three peaks in the x-ray spectrum, suggests that control circuitry will soon be an integral part of all ultrafast laser systems. There is no better place than JILA to undertake such studies. For example, design and fabrication of a new low-pressure, hollow-core fiber gas cell were significantly advanced by the expertise of the glass and machine shops. The simplicity of the design that resulted will make it a technological standard for this work and will enable the proliferation of tabletop, laser-based x-ray sources and the myriad applications likely to result. Materials Interactions and Characterization Over the past few years, JILA has capitalized on its tremendous knowledge and experience in optics to provide new tools and methods for characterization of electronic materials. JILA brings its strength and experience in instrumentation development, photonics, and optics to bear on an important class of problems, developing a capability with a tremendous opportunity for future growth. Several investigators are participating in a very successful program using NSOM, an initiative supported by NIST Competence funds. Two experimental scientists have taken advantage of the intense, localized electric field enhancements that occur near the tip of an atomic force microscope probe to sample nanostructures in an evanescent laser field with 2- to 10-nm-scale resolution. A theoretician has joined this collaboration, looking at the theory of nanoscale field effects. The newest thrust has been toward single-molecule confocal microscopy, which now allows the spectroscopic isolation and study of single molecules, fluorescent proteins, and nanostructures in the condensed phase. These methods were most recently used to probe slow recombination dynamics of electron hole pairs in single CdSe semiconductor quantum dots, which are responsible for “blinking” (i.e., abrupt transformation back and forth between optically “bright” and “dark” states). JILA researchers have been able to

OCR for page 105
An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES: Fiscal Year 2000 observe these recombination dynamics over an unprecedented dynamic range (nine orders of magnitude), which has revealed intrinsically nonexponential kinetics that result from and provide a measure of the dense, inhomogeneous distribution of electron-hole trap states in 3-nm nanostructures. Another JILA scientist has developed several new scanning near-field probes, most notably a scanning IR near-field microscope. Using tapered, infrared, transparent fiber-optic tips and a 3-µm tunable color center laser, a spatial resolution of 300 nm (one-tenth the wavelength of the IR probe light) has been obtained, as well as an impressive absorption sensitivity of 0.01 percent transmittance. This was accomplished by probing OH absorption band modifications in patterned poly(t-butylmethacrylate) polymer containing 5 percent by weight of the photoacid generator triphenylsulfonium hexafluoroantimonate deposited on sapphire substrates, a collaboration with IBM. The IR microscope transmission at two different wavelengths shows a remarkable change in contrast with infrared wavelength. The results of these studies offer the possibility to probe acid diffusion lengths for ever-decreasing size line features in semiconductor lithography. Three recently hired Fellows extend the materials program to include nonlinear time-dependent techniques. One of these Fellows has established an experimental program in studies of photon echoes, dephasing, and wave-mixing experiments in quantum well and quantum dot samples and is using second-harmonic generation techniques to characterize the Si-SiO2 interface. The two others have joined with an established Fellow to pursue the use of ultrafast x rays to measure photoelectron spectra during reactions and dissociation of species in the gas phase and adsorbed on surfaces. The core-level shifts thus obtained provide direct information about the chemical environment and bonding of atoms and allow the reactivity and chemistry of these species to be followed. These x-ray sources based on ultrafast lasers promise to complement synchrotron radiation as a convenient and transportable means of chemical analysis. The biggest issue faced by the JILA materials program is the development of closer ties to nearby research groups that produce and study advanced electronic materials, since more rapid development of new, advanced materials occurs when the growth, characterization, and study occur in continuous feedback. JILA has a genuine opportunity to influence nearby institutions and to enhance its program through additional coupling with programs going on at the University of Colorado campus and at NIST Boulder. There appears to be opportunity for more fruitful collaboration with materials researchers in the CU chemistry, physics, and materials science departments and in the NIST Boulder laboratories. Some collaborations are already occurring, but more seem possible. Atomic and Molecular Interactions and Chemical Physics JILA investigators continue to lead the world in experimental and theoretical investigations of ultracold quantum degenerate gases. Recent breakthroughs include the first realizations of a quantum degenerate Fermi gas of atoms, observation of vortices in Bose-Einstein condensates, and dynamic manipulation of the interaction strength in a rubidium-85 (85Rb) condensate. The realization of a quantum degenerate Fermi gas (described above) opens a new field of research. The vortex creation work evolved from a series of beautiful and important experiments aimed at clarifying the nonlinear dynamics of a system of two coupled Bose condensates. The 85Rb work enters exciting new experimental and theoretical territory in which existing paradigms might fail. The experimental program is tightly integrated with theory, an essential feature of the best-in-the-world status of this research. Many of the new techniques being developed at JILA, such as femtosecond EUV, ultrasensitive and ultrahigh-resolution laser techniques, and phase-controlled 10-fs pulses, can be used to interrogate single molecules and create and probe localized excitations of large molecules and complex bulk

OCR for page 105
An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES: Fiscal Year 2000 materials. Both approaches are valuable because they distinguish a simple system within a complex one and permit monitoring of the evolution of the simplest possible subunits of a larger system. This unites the interests of physical chemistry, which is increasingly concerned with complex systems, and of atomic, molecular, and optical (AMO) physics, which is probing new limits of simple systems. Interest in coherent control and quantum computing is stimulating new research into phase control in atoms and molecules. Phase and amplitude control is investigated in the preparation and probing of vibrational and rotational wave packets. In new work at JILA, an eight-state phase control process has been demonstrated in a lithium dimer, in which eight states are simultaneously created in a superposition state with precise phase control of each state to about one degree of phase. The decoherence rates of these phase-controlled superposition states are being explored to determine their suitability for quantum computing. New directions in ultrafast photophysics and the spectroscopy of complex systems and short-lived species are bearing fruit. One group is using the method of extended spectral cross-correlation to unravel the complex dynamics of the photodissociation of ammonia and all of its deuterated analogues via a graphical representation. The separation of fragment distributions by pattern recognition not only yields spectral patterns that are less complicated to assign but also reveals physical insights into the chemical process without even assigning the product spectra. The powerful combination of slit jet expansions and confined, pulsed discharges developed by another group now provides unprecedented capabilities for generating intense concentrations of highly reactive species such as hydrocarbon radicals and molecular ions, but under the greatly simplifying conditions of a supersonic cooled jet in which temperatures near 10 K can be achieved. This has permitted the first detailed spectroscopic investigation of many hydrocarbon radical species important in combustion processes. The assignment of these spectra via conventional room-temperature or elevated-temperature spectroscopy would have been experimentally intractable. These intense radical sources have also proven invaluable in crossed molecular beam studies, where they were used in conjunction with sensitive, direct IR laser absorption methods to facilitate the study of simple bimolecular reaction events at the single-collision, quantum state-to-state level of detail. A third group's investigations of ultrafast photodynamics in negatively charged gas-phase ionic clusters provide new insights in two important areas. Investigations of femtosecond-scale photoexcitation processes in solvated negative ions generate insights into the role of the solvent in mediating open dissociation channels (the “cage” effect). When the formation of an unstable neutral species, initiated by photodetachment of an electron from a stable polyatomic anion to form an unstable neutral species, is coupled with an ultrafast laser probe, the entire bond rearrangement reaction coordinate is revealed. Researchers at JILA and other institutions are working to connect phenomena found in gas-phase cluster work to similar condensed-phase behaviors, with notable initial success. Astrophysics At present, JILA employs seven astrophysics Fellows from the CU Astrophysical and Planetary Sciences (APS) Department and several adjoint Fellows who remain active in astrophysics-related research. The overlap in research interests between JILA's APS and physics and chemistry Fellows is not large, although in some areas such as gravity wave detection, there is a very productive interaction. APS Fellows are doing world-class research in many different areas and are at or near the cutting edge in most of these endeavors. They accounted for about 29 percent of the 1998-1999 publications by JILA scientists, essentially the same as their proportion of APS Fellows at JILA. Most of their publications were in highly respected peer-reviewed journals. A few highlights illustrate this.

OCR for page 105
An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES: Fiscal Year 2000 Six JILA Fellows are involved in mission definition studies of the Laser Interferometer Space Antenna (LISA), a spaceborne laser interferometer mission for the detection of gravity waves. This is potentially a wonderful marriage of the unique prowess and experience of the QPD in laser-based metrology with cutting-edge astrophysics research. LISA will be capable of detecting gravity waves from the formation of massive black holes in galaxy mergers, from stellar collapse events and from compact star binaries in our own galaxy, thus opening a dramatic new window onto our universe. This relates to theoretical work at JILA on numerical simulation studies of the behavior of matter falling into and around black holes and compact stars. JILA efforts on LISA were recently rewarded when LISA became part of the NASA Office of Space Science's strategic plan. LISA is now being considered for a joint mission with the European Space Agency for flight in 2010. Another JILA research group continues to be very active in designing and using spaceborne experiments (largely with the HST) to study many aspects of astrophysics, from detailed studies of the atmospheres and coronas of stars to detailed mapping of the structure of the local interstellar cloud. This group is also determining the relative abundance of deuterium, work that has enormous cosmological implications regarding the present baryonic density and ultimate fate of the expanding universe. Theoretical astrophysics continues to thrive at JILA. One group has been working on computer models of the explosion from supernova SN1987A. It has developed detailed predictions of what to expect as the blast wave from the supernova slams into surrounding interstellar matter over the next few years. These predictions are now being tested with observations from the HST Imaging Spectrometer and the Advanced X-ray Astrophysics Facility and Roentgen Satellite. Another Fellow has been carrying out theoretical studies of astrophysical fluid dynamics with particular reference to the structure and dynamics of the Sun. He has been heavily involved in inverting helioseismology data to derive the interior rotation and dynamics of flow patterns in the Sun. This type of work is right at the cutting edge of both solar and stellar structure research. A third Fellow's group has also been carrying out theoretical studies in solar physics, involving three-dimensional simulations of the interplay of magnetic fields and convection in the Sun and the effects of this interplay on p-mode global acoustic oscillations. Again, this type of research is right at the forefront of work aimed at understanding the processes that drive the Sun. The decision was made 2 years ago to transfer astrophysics from JILA to CU. The astrophysicists plan to move out of the JILA building and be cohoused with their CU colleagues; however the date for this move is uncertain because of lack of available space in other university buildings and lack of funds to construct new space. The present arrangement whereby a dwindling number of APS Fellows are housed at JILA is satisfactory for the near term, but JILA Fellows will have to think carefully about new hires when replacing retiring APS Fellows. A committee has already been established to work on this challenging issue. If suitable candidates can be found, it may be possible to replace retiring APS Fellows with scientists more closely involved with the laser-based metrology interests of the QPD. The LISA project—cutting-edge, space-based laser metrology applied to the detection of gravity waves—is one area in which such an appointment might make good sense. Other possible areas might be the development of superconducting tunnel diode detectors, far-IR or submillimeter detector development, or active and adaptive optics techniques. Time Standard Distribution The JILA Fellow from the NIST Time and Frequency Division maintains an important program in time standard distribution: NIST-authenticated time certification is becoming increasingly important in commerce, especially financial trading. This researcher has created an online time transfer service that

OCR for page 105
An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES: Fiscal Year 2000 is receiving 20 million hits per day and growing at a rate of 7 percent per month. In another project, he has addressed the problem of communicating extremely accurate time measurements to a distant user. Novel methods exploiting the high-frequency carrier rather than the lower-frequency signal of the GPS have been developed that are capable of transferring time measurements at 1 part in 1014 absolute accuracy. Impact of Programs The JILA programs are actively and effectively disseminated through technical publications, invited talks, and the guest researcher program. During 1998 and 1999, 218 technical papers were published, permanent and visiting JILA staff members gave 183 invited talks, and 50 guest researchers worked at JILA. An especially noteworthy example of the impact of the scientific work at JILA has been the creation of approximately 20 BEC laboratories around the world subsequent to the pioneering, successful BEC work done at JILA. There is a plethora of technology at JILA of potential interest and value to industry, and it is part of NIST's mission to foster connections with, and support technology transfer to, industry. However, during the past 2 years, JILA efforts to foster industry connections and technology transfer to industry have been substantially less than during the previous 2-year review period. At the time of the previous review, one member of the JILA staff was spending 50 percent of his time coordinating industry activities. He is now spending 20 percent of his time on these activities. Furthermore, the number of distinguished visitors from industry has declined (one in 1996, one in 1997, two in 1998, and none in 1999), as have invited talks by industrial researchers (six in 1996, four in 1997, three in 1998, and one in 1999). Since the previous review, a National Science Foundation-funded Integrated Graduate Education, Research, and Training Award was provided to CU for its Optical Science and Engineering Program (OSEP). The staff member responsible for JILA's industrial outreach was named as assistant director, with the intention that JILA's industry activity would be driven through OSEP. This change may be related to the decline in JILA industry activity. Industry connections and technology transfer are an appropriate JILA activity. The recent decline in this activity is of concern and should not continue. The subpanel suggests that JILA (1) determine what industry activity at JILA should be; (2) review its current track record with quantifiable, meaningful metrics for industry connections and technology transfer over the past 4 to 6 years; and (3) put in place a plan that is appropriate to the overall JILA-NIST mission in this area. Resources Funding sources for the NIST Quantum Physics Division are shown in Table 5.7. Currently, the University of Colorado contributes roughly $4.7 million to JILA, the National Science Foundation contributes approximately $5.9 million, and other grants and visitor contributions total $3.8 million. This brings the total funding for JILA to approximately $20.7 million. Staffing for the NIST Quantum Physics Division currently includes 11 full-time permanent positions, of which 9 are for technical professionals. There are also seven nonpermanent and supplemental personnel, such as postdoctoral fellows and part-time workers. Among the University of Colorado staff, there are 17 JILA Fellows. JILA counts one Time and Frequency Division and nine QPD researchers among its Fellows and Fellow-track members, with expertise in chemistry, physics, and optoelectronics. Eight additional Fellows are members of the CU chemistry and physics faculties and seven Fellows are CU astrophysicists.

OCR for page 105
An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES: Fiscal Year 2000 TABLE 5.7 Sources of Funding for the NIST Quantum Physics Division (in millions of dollars), FY 1997 to FY 2000 Source of Funding Fiscal Year 1997 (actual) Fiscal Year 1998 (actual) Fiscal Year 1999 (actual) Fiscal Year 2000 (estimated) NIST-STRS, excluding Competence 3.7 3.6 3.6 3.7 Competence 0.3 0.3 0.3 0.5 ATP 0.0 0.2 0.2 0.2 OA/NFG/CRADA 0.5 0.6 0.6 0.7 Other Reimbursable 1.1 1.2 1.1 1.2 Total 5.6 5.9 5.8 6.3 Full-time permanent staff (total)a 12 12 11 11 NOTE: Sources of funding are as described in the note accompanying Table 5.1. a The number of full-time permanent staff is as of January of that fiscal year. The topic of the resources necessary to maintain JILA as a center of excellence is inextricably bound to the way JILA defines itself as an institute as it contemplates the eventual departure of its astrophysical component. Two years ago, departure of the astrophysicists from JILA seemed more immediate. The subpanel is impressed with the cooperation and good will that prevail as the astrophysicists separate from the AMO-materials researchers at JILA, even as it has become clear that astrophysics is likely to inhabit the JILA site for another 10 years. The collegiality represented by this cooperation is remarkable. The subpanel remains concerned, however, about the effect of the present situation on appointments, infrastructure, and space allocations. The subpanel's last report noted that “JILA stands today at the edge of an exciting new era. Its scientific achievements over the past few years have been outstanding and recent support of the Laboratory by NIST management has been excellent. ” This remains true today. The 1998 subpanel report ended with the observation that “now is the time to define the JILA of the future through careful discussion and planning,” and the 2000 subpanel is particularly interested in progress made toward this goal in the intervening 2 years. Some important issues arose during that time, and a number of questions posed in 1998 by this subpanel require follow-up. The subpanel found that although considerable planning and debate have surrounded the recruitment of new Fellows, rather less discussion has been devoted to larger issues at JILA, particularly a vision for the new JILA that will emerge after the departure of its astrophysics community. The subpanel urges JILA Fellows to devote time to this very important task. Such a vision will be needed for development of strategic plans to address some of the resource issues discussed in this section. Staffing Fellows. As noted in the section “Technical Merit and Appropriateness of Work,” the subpanel was extremely impressed by the quality of JILA's newest hires. These new Fellows and Fellow-track scientists have quickly established themselves as a vital part of the JILA community. The subpanel applauds the efforts under way to form a committee within JILA to consider recruitment of an astrophysicist with strong AMO connections. However, the subpanel is concerned that an attempt to bring in

OCR for page 105
An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES: Fiscal Year 2000 such a “hybrid” appointment may require unwise compromise on the part of either the astrophysics or the AMO components of JILA, or both. Given the 10-year horizon for physical separation of the astrophysics and the AMO-materials parts of JILA, the subpanel urges caution and vigilance with regard to maintaining the collegial atmosphere and spirit of cooperation, especially in the area of appointments. The subpanel hopes that the university can find a way to speed up the physical separation of the two groups. Other new appointments being considered also require a commitment to new resources and collaborative interactions. The scientific evolution and growth of JILA through new appointments is the sine qua non for any endeavor of this kind; nevertheless, there is a delicate balance to be struck between present capabilities and future potential that must be addressed with care. The present search for a new JILA Fellow in optical biophysics would bring the laboratory into an exciting new area, one of strong national interest. However, a new Fellow trained in biochemistry or biophysics would need access to a number of facilities and collaborators not available within JILA. Some of these are available in other departments at the University of Colorado, but bridges must be carefully built to those departments now so that a new Fellow in this area can flourish. Future appointments are also being considered in nanomaterials and molecular electronics. In this area, access to nanofabrication facilities and similar support is a must, as pointed out in the discussion of materials in the section on technical merit. The subpanel notes that although such facilities already exist at the NIST Boulder campus, they have not yet been accessed by JILA scientists. It would seem appropriate for NIST management to consider how interaction between JILA and NIST Boulder might be fostered more strongly, especially if JILA brings in a new Fellow in this area. The subpanel also recommends that JILA consider establishing a committee to liaise with several university departments (chemistry, physics, materials science, biochemistry, for example). Doing so would build both good will and the bridges that will be needed to establish successful new endeavors in optical biophysics and molecular electronics. Staff, Students, and Postdoctoral Researchers. Members of the subpanel visited with JILA staff, senior research associates, postdoctoral scientists, and graduate students in order to learn their views of JILA. Generally, all were happy to be working at JILA. They believe that they are appreciated and able to work effectively. Although some complained about a heavy workload, even they felt that JILA is a good place to work. An important reason for this seems to be an appreciation of the teamwork among the staff and a feeling of being valued by the scientists. This climate of respect is mutual: scientists recognize that their work depends on support staff, and support staff take pride in and ownership of JILA 's scientific achievements. Students recognize the valuable support provided by staff. Some potential issues should be noted here. First, JILA management should recognize that the staff believe their productivity has been pushed to its maximum. Staff are concerned that the quality of services they can provide to JILA might suffer from any increase in workload. This needs to be considered as JILA expands its technical programs. Second, the different cultures within the astrophysics and AMO communities regarding the length of tenure for postdoctoral research associates creates some friction for these researchers. This seems to particularly impact the astrophysics postdocs, who find that some JILA policies do not accommodate their generally longer tenure at JILA. Management. JILA's current management structure—rotation of the JILA chair among the Fellows as a 2-year position —is well-suited to JILA's unique character. It allows the Fellows to maintain active scientific programs while assuming this leadership role. Continuity in leadership is provided by the QPD division chief, a long-term appointment. The good working relationship between the NIST and JILA managers enables a smooth-running organization.

OCR for page 105
An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES: Fiscal Year 2000 Facilities JILA faces several challenges with respect to its physical facilities. The subpanel was particularly concerned about the many complaints from Fellows, postdocs, and students about environmental control within the JILA complex. The major problem seems to be serious temperature fluctuations in the buildings over each 24-hour period. The fluctuations in temperature reduce the running time for experiments by nearly half each day, thereby reducing productivity by much more than half, since these experiments generally benefit from a momentum effect in which the amount of data collected and the results rise sharply the longer the experiment is in operation. There were also complaints about dust and vibrations. This is the premier optics laboratory in the world, a place where dust and significant temperature fluctuations simply cannot be tolerated. The university's facilities management appears to be unresponsive to the building problems. The subpanel urges NIST management to work with the University of Colorado to find a solution to the serious heating, ventilation, air conditioning, and other environmental issues that beset JILA at this time. JILA also faces a serious space shortage that will become acute within 3 to 5 years. This will arise from the hiring of new Fellows and the expansion of the activities of recently hired Fellows, both necessary to the continued health of the institution. This situation will not be solved by the eventual departure of the astrophysics group from JILA. The astrophysics group largely occupies office space, while the most serious need at JILA in the foreseeable future is for laboratory space. Retirements, the natural way in which space was recycled in the past, do not seem likely to yield this beneficial “renewal” in the near future. This is due to the elimination of mandatory retirement as well as to the increased health and longevity of the population. In addition, attractive retirement packages frequently include an allotment of space that allows a still-vigorous retired Fellow to continue worthwhile activities. Such inducements to retire help to solve salary issues but leave JILA with an acute space shortage. The subpanel urges NIST management to work with the university to solve the space problem so that this remarkable laboratory can continue its impressive successes in the new century. Major Observations of the Subpanel JILA is a most extraordinary institution, and NIST receives enormous technical benefit from participating in it. Its international status as a center for precision metrology and interdisciplinary studies utilizing the interaction between light and matter is unrivaled. The subpanel finds that JILA has made excellent hires in the past 3 years; these newcomers have already set new directions for JILA, while contributing to the research directions of more senior staff. JILA's strength derives from the unprecedented number of important collaborations among the Fellows: these were found to be lively and growing. The already world-leading excellence of JILA continues to grow, thanks to the confluence of key elements of success. The partnership between CU and NIST; the synergy, creativity, and vigor of JILA's researchers; adequate and flexible funding; superb technical support; inspired management; and the physical proximity of the researchers all serve to promote multiple cross-disciplinary collaborations. The subpanel observes that JILA's high level of excellence would be made vulnerable by a decline in any of these elements of success. NIST and CU have made outstanding new appointments to the roster of JILA Fellows, laying the foundation for a rapid expansion of JILA 's already frontier-shattering achievements. The subpanel applauds the search and hiring process, which has been carried out with great wisdom, vigilance, and care. Two additional NIST Fellows in new disciplines will be added in the near future, and other new

OCR for page 105
An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES: Fiscal Year 2000 appointees will replace retiring Fellows over the next 5 to 10 years. The subpanel is confident that future searches will be as careful as those of the past few years. It recommends that as new Fellows with interdisciplinary research programs are hired—for example, in nanotechnology and optical biology—new partnerships be built and nurtured within NIST and between NIST and CU. These partnerships might include new collaborations and shared laboratories, giving a critical mass of researchers and access to necessary resources (expertise, equipment, and facilities) for the new Fellows, thus ensuring the success of their research programs. The continued excellence of JILA depends on sufficient laboratory space of appropriate quality and quantity to allow the programs of the newly hired Fellows to grow and to accommodate future Fellows. The subpanel finds that such space is not readily available in the JILA building. The subpanel also finds that upgrades to existing laboratories will be vital to remedy severe problems with temperature control, dust, and vibration that interfere with experimental progress. NIST and CU are urged to find ways (e.g., new construction and/or remodeling) to solve these problems. The plans for the future of JILA presented 2 years ago are being reshaped since the CU astrophysics Fellows will remain part of JILA for the foreseeable future. This evolution is appropriate and necessitates careful planning to optimize the ties between the two technical communities within JILA. It is essential that the JILA Fellows continue to work on a comprehensive, long-term strategic vision for the institute. The interdisciplinary, collaborative character of JILA is its hallmark. As JILA's technical focus evolves away from its original mission of laboratory astrophysics, strong ties to all of the CU academic departments with which it is most closely allied—chemistry, physics, astrophysics, electrical engineering—are of vital importance. The subpanel finds that these ties are receiving renewed attention, and it encourages JILA to continue to place high priority on strengthening them.

OCR for page 105
An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES: Fiscal Year 2000 This page in the original is blank.