In 2015, at the request of the Director of the National Institute of Standards and Technology (NIST), the National Research Council (NRC)1 formed the Panel on Review of the Physical Measurement Laboratory at the National Institute of Standards and Technology (referred to in this report as “the panel”) and established the following statement of task for the panel:
The National Research Council shall appoint a panel to assess the scientific and technical work performed by the National Institute of Standards and Technology (NIST) Physical Measurement Laboratory (PML). This panel will review technical reports and technical program descriptions prepared by NIST staff and will visit the facilities at the Physical Measurement Laboratory. Visits will include technical presentations by NIST staff, demonstrations of NIST projects, tours of NIST facilities, and discussions with NIST staff. The panel will prepare a report summarizing its assessment findings.
NIST specified that the nine divisions of the PML would be reviewed: the Applied Physics Division (APD), Engineering Physics Division (EPD), Office of Weights and Measures (OWM), Quantum Electromagnetics Division (QED), Quantum Measurement Division (QMD), Quantum Physics Division (QPD), Radiation Physics Division (RPD), Sensor Science Division (SSD), and Time and Frequency Division (TFD).
GENERAL OBSERVATIONS
The PML remains an outstanding institution of the highest standards and accomplishments. Broadly speaking, the PML is dedicated to three fundamental and complementary tasks: (1) increase the accuracy of our knowledge of the physical parameters that are the foundation of our technology-driven society; (2) disseminate technologies by which these physical parameters can be accessed in a standardized way by the stakeholders; and (3) conduct research at both fundamental and applied levels to provide knowledge that may eventually lead to advances in measurement approaches and standards.
The scientific staff is of uniformly high quality, but preserving the quality of the staff will be a challenge because of the large number of anticipated retirements of such excellent staff. The physical infrastructure of the PML is heterogeneous and complex but still fundamentally adequate to the tasks at hand. It is generally of a world-class quality, although there remain some weak infrastructure areas in the Radiation Physics Division that need to be addressed immediately.
The PML is a large organization, dispersed on two main campuses, one at Gaithersburg, Maryland, the other at Boulder, Colorado.
It is vital that the excellence of the PML be maintained as the United States faces increasing competition for resources and technology from rapidly advancing countries.
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1 Effective July 1, 2015, the institution is called the National Academies of Sciences, Engineering, and Medicine. References in this report to the National Research Council are used in a historical context identifying programs prior to July 1.
SIGNIFICANT ACCOMPLISHMENTS
Applied Physics Division
Electron beam lithography has been used by the Applied Physics Division (APD) to pattern nanowires into a thin film made of a heat-tolerant ceramic superconductor, molybdenum silicide, operated at the superconducting transition edge temperature. The new design operates at higher temperatures and bias current. Timing jitter is now 76 picoseconds, and detector quantum efficiencies are 87 percent at wavelengths that are useful in telecommunications.
Quantum Electromagnetics Division
The Quantum Electromagnetics Division (QED) has developed a new type of sensor that can be used to investigate the isotopic composition of plutonium samples, a critical measurement for nuclear nonproliferation efforts and related forensics, as well as for environmental monitoring, medical assays, and industrial safety.
Engineering Physics Division
The Engineering Physics Division (EPD) has developed a system for forensic analysis of spent bullet casings. Use of microscope images of three key markings typically found on spent cartridge cases dramatically reduces the uncertainty levels for the firing pin and breech face markings, which investigators can use to determine their confidence levels about a match.
Office of Weights and Measures
The Office of Weights and Measures (OWM) has proposed a standard for plug-in electric car customers to standardize what they should be charged for their electrical charge, and what requirements operators should meet. This standard, produced by NIST’s U.S. national work group on electric vehicle refueling and submetering, was adopted by the National Conference on Weights and Measures (NCWM) at its 2015 annual meeting.
Quantum Measurement Division
The Quantum Measurement Division (QMD) has performed experimental studies of many-body effects in ultracold atomic systems that are among the best in the world, and the recent test of Bell inequalities, eliminating the remaining loopholes of previous experiments, is a telling example of the synergy between different areas of expertise in Gaithersburg and at JILA, a joint institute of NIST and the University of Colorado, Boulder.
Quantum Physics Division
The work on spin exchange of ultracold molecules is a new testing ground, enabled by tools that have been developed at the Quantum Physics Division (QPD). It will address fundamental questions of molecule–molecule interactions and can be used as a quantum simulator of many-body spin dynamics.
Radiation Physics Division
The Radiation Physics Division (RPD) has implemented a new Co-60 therapy-level calibration facility with state-of-the-art data acquisition and operating capabilities. It is expected to help improve the ability to maintain a number of dosimetric standards essential to the radiation oncology community.
Sensor Science Division
The Sensor Science Division (SSD) has performed work on characterization of hydrogen flow meters for high-pressure refueling of hydrogen-powered vehicles, with reduced uncertainty and rapid response times. A portable field test standard has been developed for use at refueling stations. This work is important as the world seeks alternatives to fossil fuels.
Time and Frequency Division
The Time and Frequency Division (TFD) has generated optical frequency combs through nonlinear wave mixing in optical microresonators. Such microcombs offer dramatic size reduction compared to frequency combs derived from mode-locked lasers, opening the possibility of applications beyond specialized laboratory settings. Researchers have developed new methods for fabricating high-quality-factor optical microresonators at low cost and high speed.
KEY SUGGESTIONS FOR IMPROVEMENT
The quality of work done at the PML and its response to the stakeholders whose interests the PML addresses are excellent. Each division deserves high accolades.
Applied Physics and Quantum Electromagnetics Divisions
The restructuring of the former Quantum Electronics and Photonics Division and the Electromagnetics Division into the Applied Physics Division (APD) and the Quantum Electromagnetic Division (QED) seems to have been accomplished smoothly. However, the decision by the PML to have the panel jointly review the two divisions as one entity has created some confusion and did not allow an in-depth analysis of each division. The APD as a consequence needs to be analyzed in more depth in coming reviews to provide a clearer view of its mission and how it fits into the overall PML effort.
Engineering Physics Division
It will be important that the Engineering Physics Division (EPD) avoid duplication of effort in the area of nontraditional materials conducted by better-funded teams investigating the science or technology of these speculative materials systems.
Quantum Electromagnetics Division
The Quantum Electromagnetics Division’s (QED’s) optical quantum entanglement work was not at the fundamental leading edge of such work, which is being carried out by many other groups worldwide. It would be worthwhile to focus more on areas where the division has real strengths, such as photon sensors.
The work in nuclear magnetic resonance (NMR) imaging, while strong, needs to be expanded to include the rapidly growing area of functional NMR imaging (fMRI), so that claims made in the literature can be evaluated more carefully.
The Quantum Sensors group has had a significant impact in millimeter wave polarimetry with its detector arrays, but the group serves so many external groups that it runs the risk of becoming oversubscribed.
PML staff suggested that the Gaithersburg and Boulder nanofabrication facilities could support a significantly greater number of NIST projects or outside collaborators. The new facility established at the University of Maryland further disperses the division and could present difficulties for its current cohesiveness and collaborations.
PML staff report that overhead charges on graduate students and on capital equipment are excessive.
Office of Weights and Measures
The effort by the metric program in the Office of Weights and Measures (OWM) to implement the SI units in the United States is lagging. Better quantitative metrics for the effectiveness of the Legal Metrology group needs to be established. The number of accredited and recognized laboratories at the state level for dissemination of mass and volume standards for stakeholders is declining.
PML predicts a large wave of retirements (50 percent of staff) in this office in the coming 5 years, and PML needs to examine the implication of the retirements and determine what replacements, if any, will be required.
Quantum Measurements Division
The partial relocation of the groups working in the Quantum Measurements Division (QMD) to the University of Maryland campus as the Joint Quantum Institute presents both opportunities and challenges and warrants careful monitoring so that the groups do not become isolated.
It will be important that the Synchrometrology Group have sufficient resources to play a role in the upcoming renovation of the national power grid into a smart grid. This effort will have a worldwide scope.
Quantum Physics Division
The powerful Quantum Physics Division (QPD) has successfully evolved new opportunities from initial objectives. The group may be rapidly evolving toward nanotechnology and biotechnology; it may be worthwhile to plan for this evolution rather than expect it to occur organically.
The scientific interests of the division show strong overlap with those of the Time and Frequency Division, but given that both divisions have been extremely successful, this can be viewed as increasing critical mass in areas in which NIST is a world leader.
The activities in biological physics have not been well integrated with those of other efforts within the QPD. PML needs to examine the relationship of biology to other division efforts. The division
needs to develop firm guidelines for a consistent and clear approach to the development of intellectual property.
Several staff spoke of a high overhead rate on capital equipment; they suggested that this makes acquisition of expensive equipment very difficult.
Radiation Physics Division
Building 245 in which the Radiation Physics Division (RPD) is primarily housed, is approaching a dangerous and unsafe condition; immediate attention is warranted. In the laboratories of Building 245, where most of the radionuclide standards are prepared for shipment, the rooms are old and lacking in proper heating and ventilation, with consequent inadequate control of humidity and temperature. Neutron source standardization is carried out in a number of shielded, below-grade laboratories in Building 245. Water intrusion during heavy rains has become an issue because the building is no longer watertight. Dispersal of the source material is remotely possible, but the immediate concern is damage and loss of calibration traceability. These events are, at a minimum, distractions to overburdened scientists, and in some cases have threatened to flood sources under test.
The Dosimetry Group primarily works with its large stakeholder community. Providing more opportunity and support to do research would enhance the quality of the staff and the work done.
Lack of funds is resulting in nonreplacement of retiring critical employees and in requiring Ph.D.-level staff to do routine tasks, stealing time from their technical work. Unfortunately, there are examples where dissemination of proper radioactivity standards has not been able to proceed as rapidly as required owing to a lack of funds.
The division needs to strengthen the training program that involves students and postdoctoral researchers in each of the critical standards activities and to foster a program to share equipment and facilities with users at other national laboratories and universities.
Sensor Science Division
One possible caution for the Sensor Science Division (SSD) concerns the increasing emphasis on lower-cost, lower-SWAP sensors for future satellite systems. The division could prepare to calibrate much smaller radiometers for its customers. As microfluidics becomes ever more important, it will be correspondingly important to continue developing noninvasive and inline ways to determine microflows.
While the overarching strategy was well articulated, the division did not describe plans for some of the projects, particularly those that are funded externally; those working on internally funded initiatives seemed to have more concrete plans. The division needs to clarify plans for externally funded projects.
Retirements are being delayed because of difficulties in finding appropriate replacements.
Time and Frequency Division
The NIST-on-a-Chip effort will involve this division, which needs to expand development of its roadmap for this work. The Time and Frequency Division’s (TFD’s) scientific expertise evident during the review was primarily of an experimental nature. As stabilities and accuracies of frequency standards continue to improve, strong theoretical support will be required. The division needs to consider whether the theoretical expertise resident within the division is sufficient to support future experimental efforts.
TFD staff have mentioned the shortage of meeting and collaboration space. Staff also expressed concern about the onerous procurement process, which, they said, incurs substantial delays.
The emphasis on patent preparation does not appear to be stable from year to year. A careful assessment by the division of the value of patenting would be worthwhile. Once the value proposition is in hand, more consistent direction to staff can be provided.
