AN ASSESSMENT OF 

SELECTED DIVISIONS OF THE 

PHYSICAL MEASUREMENT LABORATORY 

AT THE NATIONAL INSTITUTE OF 

STANDARDS AND TECHNOLOGY 

FISCAL YEAR 2021 

Panel on Assessment of Selected Divisions of the Physical Measurement Laboratory 

at the National Institute of Standards and Technology 

Committee on NIST Technical Programs 

Laboratory Assessments Board 

Division on Engineering and Physical Sciences 

A Consensus Study Report of 



 
THE NATIONAL ACADEMIES PRESS 500 Fifth Street, NW Washington, DC 20001 

This activity was supported by Contract No. SB13411CQ0017 with the National institute of Standards 

and Technology Any opinions, findings, conclusions, or recommendations expressed in this publication 

do not necessarily reflect the views of any organization or agency that provided support for the project. 

International Standard Book Number-13: 978-0-309-09371-2 

International Standard Book Number-10: 0-309-09371-6 

Digital Object Identifier: https://doi.org/10.17226/26312 

Additional copies of this publication are available from the National Academies Press, 500 Fifth Street, 

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Copyright 2021 by the National Academy of Sciences. All rights reserved. 

Printed in the United States of America 

Suggested citation: National Academies of Sciences, Engineering, and Medicine. 2021. An Assessment of 

Selected Divisions of the Physical Measurement Laboratory at the National Institute of Standards and 

Technology: Fiscal Year 2021. Washington, DC: The National Academies Press. 

https://doi.org/10.17226/26312. 
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v 

PANEL ON ASSESSMENT OF SELECTED DIVISIONS OF 

THE PHYSICAL MEASUREMENT LABORATORY AT 

THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY 

DWIGHT C. STREIT, NAE,1

 University of California, Los Angeles, Chair 

ROBERT H. AUSTIN, NAS,2

 Princeton University 

DAVID J. BISHOP, NAE, Boston University 

JOHN E. BOWERS, NAE, University of California, Santa Barbara 

MALCOLM S. CARROLL, Princeton University 

ROBERT P. COLWELL, NAE, University of Illinois, Urbana-Champaign 

BRIAN L. DEMARCO, University of Illinois, Urbana-Champaign 

SHAHEEN AZIM DEWJI, Georgia Institute of Technology 

RANDALL H. GOLDSMITH, University of Wisconsin, Madison 

JEFFERY C. GUST, Fluke Corporation 

RICHARD A HAIGHT, IBM Thomas J. Watson Research Center 

CAROL A. HANDWERKER, Purdue University 

MARY CYNTHIA HIPWELL, NAE, Texas A&M University 

IGOR JOVANOVIC, University of Michigan 

STEVEN M. LARSON, NAM,3

 Sloan Kettering Institute 

CHEN-YU LIU, Indiana University 

CHRIS ALAN MACK, Fractilia 

PIERRE MEYSTRE, University of Arizona 

JOHN DAVID ROBERTSON, University of Missouri 

SUSAN J. SEESTROM, Sandia National Laboratories 

NATHAN SHATTUCK, SpaceX 

MICHAEL G. SPENCER, Morgan State University 

KERRY J. VAHALA, NAE, California Institute of Technology 

VLADAN VULETIC, Massachusetts Institute of Technology 

Staff

AZEB GETACHEW, Senior Program Assistant 

EVA LABRE, Administrative Coordinator 

JAMES MCGEE, Director 

 

1

 Member, National Academy of Engineering. 

2

 Member, National Academy of Sciences. 

3

 Member, National Academy of Medicine. 
vi 

COMMITTEE ON NIST TECHNICAL PROGRAMS 

ELSA REICHMANIS, NAE, Lehigh University, Chair 

MICHAEL I. BASKES, NAE, Mississippi State University 

LEWIS BRANSCOMB, NAS/NAE/NAM, University of California, San Diego 

MARTIN E. GLICKSMAN, NAE, Florida Institute of Technology 

JENNIE S. HWANG, NAE, H-Technologies Group 

CHRISTOPHER W. MACOSKO, NAE, University of Minnesota 

C. KUMAR PATEL, NAS/NAE, Pranalytica, Inc. 

BHAKTA B. RATH, NAE, Naval Research Laboratory 

ALICE WHITE, Boston University 

Staff

AZEB GETACHEW, Senior Program Assistant 

EVA LABRE, Administrative Coordinator 

JAMES MCGEE, Director 

 
vii 

LABORATORY ASSESSMENTS BOARD 

JENNIE S. HWANG, NAE, H-Technologies Group, Chair 

MICHAEL I. BASKES, NAE, Los Alamos National Laboratory 

KEVIN MACK GATES II, Strategic Analysis, Inc. 

WESLEY L. HARRIS, NAE, Massachusetts Institute of Technology 

W. CARL LINEBERGER, NAS, University of Colorado, Boulder 

AJAY P. MALSHE, NAE, Purdue University 

C. KUMAR N. PATEL, NAS/NAE, Pranalytica, Inc. 

ELSA REICHMANIS. NAE, Lehigh University 

FRANCISCO F. ROBERTO, NAE, Newmont Corporation 

Staff 

AZEB GETACHEW, Senior Program Assistant 

EVA LABRE, Administrative Coordinator 

JAMES MCGEE, Director 

ix 

Acknowledgment of Reviewers 

This Consensus Study Report was reviewed in draft form by individuals chosen for their diverse 

perspectives and technical expertise. The purpose of this independent review is to provide candid and 

critical comments that will assist the National Academies of Sciences, Engineering, and Medicine in 

making each published report as sound as possible and to ensure that it meets the institutional standards 

for quality, objectivity, evidence, and responsiveness to the study charge. The review comments and draft 

manuscript remain confidential to protect the integrity of the deliberative process. 

We thank the following individuals for their review of this report: 

Carlos D. Bustamante, Stanford University, 

Jordan J. Green, Johns Hopkins University, 

Max G. Lagally, NAE,1

 University of Wisconsin, Madison, 

Nadya Mason, NAS,2

 University of Illinois, Urbana-Champaign, and 

Robert Schoelkopf, NAS, Yale University. 

Although the reviewers listed above provided many constructive comments and suggestions, they 

were not asked to endorse the conclusions or recommendations of this report nor did they see the final 

draft before its release. The review of this report was overseen by David W. Johnson, Jr., NAE, Bell 

Laboratories, Lucent Technologies (retired). He was responsible for making certain that an independent 

examination of this report was carried out in accordance with the standards of the National Academies 

and that all review comments were carefully considered. Responsibility for the final content rests entirely 

with the authoring committee and the National Academies. 

1

 Member, National Academy of Engineering. 

2

 Member, National Academy of Sciences. 

Contents 

SUMMARY 1 

 

1 THE CHARGE TO THE PANEL AND THE ASSESSMENT PROCESS 6 

 

2 QUANTUM MEASUREMENT DIVISION 8 

 

3 RADIATION PHYSICS DIVISION 14 

4 MICROSYSTEMS AND NANOTECHNOLOGY DIVISION 21 

5 NANOSCALE DEVICE CHARACTERIZAION DIVISION 24 

6 SENSOR SCIENCE DIVISION 28 

 

7 CROSSCUTTING CONCLUSIONS 36 

ACRONYMS 39 

1 

Summary

At the request of the Director of the National Institute of Standards and Technology (NIST), in 

2020 the National Academies of Sciences, Engineering, and Medicine formed the Panel on Assessment of 

Selected Divisions of the Physical Measurement Laboratory at the National Institute of Standards and 

Technology and established the following statement of task for the panel: 

The National Academies of Sciences, Engineering, and Medicine shall appoint three panels to 

assess independently the scientific and technical work performed by the National Institute of 

Standards and Technology (NIST) Physical Measurement Laboratory, Information Technology 

Laboratory, and Center for Neutron Research. Each panel will review technical reports and 

technical program descriptions prepared by NIST staff and will visit the facilities of their 

respective NIST laboratory. Visits will include technical presentations by NIST staff, 

demonstrations of NIST projects, tours of NIST facilities, and discussions with NIST staff. Each 

panel will deliberate findings in closed session panel meetings and will prepare a separate report 

summarizing its assessment findings. The Panel on Assessment of Selected Divisions of the 

Physical Measurement Laboratory at the National Institute of Standards and Technology will 

review the following divisions of the NIST Physical Measurement Laboratory: Quantum 

Measurement Division, Radiation Physics Division, Sensor Science Division, Microsystems and 

Nanotechnology Division, and Nanoscale Device Characterization Division. This panel will not 

access restricted information; the report summarizing its assessment will contain only public 

release information. 

The Director of NIST requested that the panel consider during its assessment the following factors: 

1. The technical merit of the current laboratory program relative to current state-of-the-art 

programs worldwide; 

2. The portfolio of scientific expertise as it supports the ability of the organization to achieve its 

stated objectives; 

3. The adequacy of the laboratory budget, facilities, equipment, and human resources, as they 

affect the quality of the laboratory’s technical programs; and 

4. The effectiveness by which the laboratory disseminates its program outputs. 

To accomplish the assessment, the National Academies assembled a panel of 24 volunteers whose 

expertise matched that of the work performed by the Physical Measurement Laboratory (PML) staff.1

 On 

May 17-20. 2021, the panel conducted a virtual review (via Internet media), a restriction imposed by the 

risks associated with the COVID-19 virus pandemic. During a plenary session, the panel received 

overview presentations by the acting NIST Director and the Director of the PML. Subsequently, the panel 

spent approximately 1.5 days receiving presentations from and engaging in discussions with the staff at 

the five divisions reviewed. On the third day, the panel met in a closed session to deliberate on its 

findings and to define the contents of this assessment report. The panel met with NIST management on 

the fourth day to clarify open questions. The choice of projects to be reviewed was made by the PML. 

The panel applied a largely qualitative approach to the assessment. Given the nonexhaustive nature of the 

1

 See the NIST Physical Measurement Laboratory at https://www.nist.gov/pmlfor information on PML 

organization and programs. 
2 

review, the omission in this report of any particular PML project should not be interpreted as a negative 

reflection on the omitted project. 

TECHNICAL QUALITY OF THE WORK

The Quantum Measurement Division has six groups, each with significant accomplishments. 

These include single-photon sources (sources that produce streams of single photons) and detectors, 

quantum optics using laser cooling, the redefinition of the kilogram, and a graphene-based Quantum Hall 

Resistance Standard. Other notable achievements include the development of a Josephson-junction–based 

waveform synthesizer for power and energy applications, a unique magnetic suspension mass comparator, 

and the investigation of photon momentum for laser power and force measurements. Some of the best 

technical programs in the world are located in this division. 

The Radiation Physics Division provides a unique resource to the United States, serving 

industrial, medical, and national security needs through its three groups. Its new gamma-radiation 

dosimetry calibration facility, detector calibration, and brachytherapy source traceability have produced 

improved calibration capability. The neutron physics program provides unique capability in the United 

States and is on par with the best neutron facilities worldwide. The neutron/X-ray tomography imaging 

facility offers the best simultaneous imaging available. The division has also developed a unique photonassisted neutron detector for fast-neutron dosimetry. The division’s excellent technical capability provides 

outstanding service to the nation developing important new radiation detection and calibration methods. 

The Microsystems and Nanotechnology Division is focused on advancing nanofabrication tools, 

technologies, and measurement systems. The three division groups work together to improve uncertainty 

in International System of Units (SI)-traceable calibration, fabricate devices such as accelerometers and 

atomic clocks, and develop nano-fluidics for biomedical applications. The study of the fundamental 

interactions of photons and phonons in nanostructures enables new tools while nonlinear optics enables 

new optical applications. 

The Nanoscale Device Characterization Division is organized into five groups whose goals are to 

transform nano-scale and atom-scale technologies, engineered materials, and solid-state devices. The 

division’s strategic areas of research are as follows: theory and measurements for alternative computing; 

microscopies for quantifying emergent properties in quantum materials and devices; advanced 

microelectronics integration, characterization, and authentication; and atom-scale solid-state device 

theory, fabrication, and measurements. The quality of the division’s work is excellent as judged by the 

significant number of peer-reviewed publications and conference presentations. 

The Sensor Science Division has responsibility for three of the seven base units of the 

International System of Units: the meter, the kelvin, and the candela. Its seven groups are aligned to 

support this significant assignment plus additional activities and programs. The technical quality of the 

division’s work is recognized worldwide through awards and commendations from multiple technical 

societies and organizations such as NASA and ASTM International (formerly the American Society for 

Testing and Materials). The division has an international reputation for technical excellence and is known 

and respected worldwide. It is highly involved in regional and international key comparisons that help to 

establish worldwide agreement on measurement standards. 

TECHNICAL EXPERTISE OF THE STAFF 

The technical expertise of the staff in the Quantum Measurement Division is outstanding and 

among the best in the world. Its research is at the forefront of the field in both theory and experiment. 

The Radiation Physics Division has scientists and engineers with world-leading capability, highimpact publications, and strong international recognition, including American Physical Society (APS) 

fellows. 
3 

The Microsystems and Nanotechnology Division staff seem fully qualified to accomplish the 

various program goals. 

The caliber and expertise of the senior researchers and associates in the Nanoscale Device 

Characterization Division is impressive. While the division staff are excellent device engineers and 

scientists, it would probably be helpful to add some systems design and engineering expertise to the team. 

The highly respected technical expertise of the Sensor Science Division staff is the foundation for 

the division’s excellent international reputation. As an example, the International Organization for 

Standardization publishes the most important standard for calibration and test laboratories, the revision of 

this standard was co-convened by a division staff member. 

ADEQUACY OF RESOURCES 

 The excellence of the staff and technical output at the PML has been maintained despite 

challenges that include, for some divisions, concerns about staffing shortages and the need for succession 

planning; and the need for facilities and equipment maintenance, upgrading, and replacement. 

Two of the groups in the Quantum Measurement Division have been integrated with the Joint 

Quantum Institute (JQI) at the University of Maryland. This facilitates collaboration with other 

researchers and enables NIST researchers to have easier access to students. However, this has also led to 

the migration of much of the Quantum Optics and Laser Cooling and Trapping Groups from the NIST 

campus to the University of Maryland Campus, although efforts and collaborations remain on the NIST 

campus. This geographical separation is exacerbated by the loss of NSF funding for the Physics Frontier 

Center associated with the JQI, and by the deferred maintenance issues back at the NIST Gaithersburg 

site, both of which impact needed space expansion. HVAC and flooding issues at the aging Gaithersburg 

facilities have also impacted the division and its overall progress; this needs to be addressed. 

The Radiation Physics Division has benefited from recent facility upgrades in their area, such as 

the Building 245 modernization project, the new high-dose-rate brachytherapy vault, and the future 10 

MeV electron beam accelerator facility. There is concern, however, that maintaining this level of 

expertise may be difficult going forward, given the loss of senior staff and the competition for new hires. 

The recent loss of senior staff has led to more time spent on immediate needs than on long-term research 

for some senior staff, which may be counterproductive in the long term. It would be productive and cost 

effective to strengthen student and post-doctoral training to help mitigate this problem. 

The Microsystems and Nanotechnology Division has extensive facilities, including two 

cleanrooms and a wide variety of fabrication and characterization tools. The PML maintains two 

fabrication facilities: one in Boulder and the other in Gaithersburg. The Microsystems and 

Nanotechnology Division has access to the Gaithersburg facility directly, and the Boulder one via 

collaboration. As with all such facilities, significant resources are required to keep the facility and tools at 

state-of-the-art levels. 

The Nanoscale Device Characterization Division has excellent resources with outstanding 

equipment. The new photo emission microscope system and planned ultraviolet femtosecond light source 

will add to a well-equipped division. 

Facilities available to support the Sensor Science Division are reported by staff to be inadequate 

to the task, and building renovations are planned to rectify this. However, the time scale for these fixes is 

such that aging infrastructure will severely limit for years the effectiveness of the division to achieve its 

goals and accomplish its mission of fostering the next generation of SI-traceable standards. 

EFFECTIVENESS OF DISSEMINATION OF OUTPUTS 

The Quantum Measurement Division has been highly effective in disseminating the results 

achieved in the division, notably including atomic spectroscopy data in the NIST Atomic Database, 
4 

publication in peer-reviewed journals and scientific conferences, and invited lectures explaining the new 

kilogram standards and the Quantum SI Revolution. 

The Radiation Physics Division regularly publishes in top-tier peer-reviewed journals. The 

Neutron Physics Group sets an excellent example with strong collaborations, summer schools and 

workshops, and a high publication rate. Given the division’s technical accomplishments, more 

engagement with universities and professional societies may benefit the dissemination of the division’s 

output in some areas. 

The Microsystems and Nanotechnology Division publishes extensively in both peer-reviewed 

journals and conference proceedings. In the previous 2 years, the division has published over 100 such 

articles. Collaborators include more than 40 top universities and research centers. The division staff are 

highly involved on conference committees, review panels, and standards bodies. 

The Nanoscale Device Characterization Division is using not only traditional means of 

distribution for its outputs, it is also using new methods such as GitHub for making new software 

available to a wide audience. The division had over 100 publications and more than 130 conference 

presentations over the past 2 fiscal years, which indicates that other researchers are well aware of the 

progress being made in the division. 

The Sensor Science Division is very effective at disseminating its results. The division staff 

publishes in high-impact journals and gives invited talks at key conferences around the world. Over the 

past 3 years, SSD staff published 240 archival journal papers, technical reports, conference proceedings, 

and book chapters. In addition, the division is proactive in organizing workshops and interlaboratory 

comparisons. 

CROSSCUTTING CONCLUSIONS 

The following conclusions apply to more than one group or program in the PML that was 

reviewed. 

Technical Quality of the Work

 The accomplishments of the PML’s staff are many and significant, spanning an extremely broad 

array of topics and including both research and support of the practical development of measurement 

standards. The staff innovatively develop and apply novel devices and techniques to solve important 

problems that affect industry, academic researchers, federal government agencies, and society in general. 

The work of the PML staff is effectively aligned with the NIST mission and is frequently performed in 

collaboration with researchers from those organizations. 

 The PML staff made commendable contributions during the COVID-19 pandemic. From March 

2020, when staff were required to work remotely, PML staff ensured that essential services were 

performed for their customers, in support of national security, national well-being, and commerce. PML 

staff also answered the call to address measurement issues relating to combatting the virus, such as 

disinfecting agents and storage of vaccines. 

Technical Expertise of the Staff 

 All the divisions of the PML have scientific and engineering staff with the appropriate level of 

expertise to deliver on their mission. In many cases, the staff are the best or among the best in their field 

of research. Staff have received numerous awards from professional organizations and from the 

Department of Commerce, which houses NIST. 

 The gender and minority employment gaps that are still strongly and broadly plaguing science, 

technology, engineering, and mathematics (STEM) fields remain an acknowledged, significant challenge 
5 

at NIST as well. The PML has implemented a plan to improve equity, diversity, and inclusion that 

involves the following features: monitoring promotion and salary data to ensure an equitable process; 

publishing promotion criteria so that staff know what is expected; mentoring by supervisors on how to 

advance; reviewing the pay level of all staff members with more than 8 years of service; participating in 

the APS’s Inclusion, Diversity, and Equity Alliance (APS-IDEA) in partnership with Howard University; 

sponsoring of and participating in conferences to increase women and minority participation in physics 

and other STEM fields; and supporting the PML Inclusivity Council, an internal grassroots organization 

working to identify barriers to inclusion and propose remedies. Addressing the challenge of staff attrition 

could provide opportunity to address diversity challenges as well. It is expected that in future years PML 

will demonstrate greater efforts and progress in diversity, equity, and inclusion. 

Adequacy of Resources

 Generally, but with significant exceptions, the PML staff are provided with adequate equipment 

and facilities to perform their tasks to a high degree of quality. Noteworthy exceptions include aging 

facilities in urgent need of upgrade, delayed maintenance on aging equipment, and an apparent lack of 

supercomputing support. All divisions reported concern about the adequacy of staffing levels, particularly 

given an aging workforce and severe competition for postdoctoral researchers and other new hires. Each 

division indicated initiation of strategic planning exercises with an eye toward addressing the current and 

predicted challenges associated with the limitations of equipment, facilities, and human resources. 

Effectiveness of Dissemination of Outputs

 PML staff are effectively disseminating the results of their work through appropriate means that 

include publication of research results; delivery of standard reference materials and standard reference 

data; performance of calibrations for industrial, academic, and government customers; participation on 

standards committees; sponsorship of workshops; and educational programs. Some customers, however, 

have complained about the amount of time it takes and the cost associated with purchased calibration 

services. They have also complained about the inadequate information provided by the web-based NIST 

Storefront interface for purchasing measurement services and about the lack of information about which 

services are currently available. 
6 

1 

The Charge to the Panel and the Assessment Process 

At the request of NIST, the National Academies of Sciences, Engineering, and Medicine has, 

since 1959, annually assembled panels of experts from academia, industry, medicine, and other scientific 

and engineering environments to assess the quality and effectiveness of the NIST measurements and 

standards laboratories, of which there are now six,1

 as well as the adequacy of the laboratories’ resources. 

At the request of the Director of NIST, in 2020 the National Academies formed the Panel on 

Assessment of Selected Divisions of the Physical Measurement Laboratory at the National Institute of 

Standards and Technology and established the following statement of task for the panel: 

The National Academies shall appoint three panels to assess independently the scientific and 

technical work performed by the National Institute of Standards and Technology (NIST) Physical 

Measurement Laboratory, Information Technology Laboratory, and Center for Neutron Research. 

Each panel will review technical reports and technical program descriptions prepared by NIST 

staff and will visit the facilities of their respective NIST laboratory. Visits will include technical 

presentations by NIST staff, demonstrations of NIST projects, tours of NIST facilities, and 

discussions with NIST staff. Each panel will deliberate findings in closed session panel meetings 

and will prepare a separate report summarizing its assessment findings. The Panel on Assessment 

of Selected Divisions of the Physical Measurement Laboratory at the National Institute of 

Standards and Technology will review the following divisions of the NIST Physical Measurement 

Laboratory: Quantum Measurement Division, Radiation Physics Division, Sensor Science 

Division, Microsystems and Nanotechnology Division, and Nanoscale Device Characterization 

Division. This panel will not access restricted information; the report summarizing its assessment 

will contain only public release information. 

The NIST Director requested that the panel focus its assessment on the following factors: 

1. Assess the organization’s technical programs. 

 How does the quality of the research compare to similar world class research in the technical 

program areas? 

 Is the quality of the technical programs adequate for the organization to reach its stated technical 

objectives? How could it be improved? 

2. Assess the portfolio of scientific expertise within the organization. 

 Does the organization have world-class scientific expertise in the areas of the organization’s 

mission and program objectives? If not, what areas should be improved? 

 How well does the organization’s scientific expertise support the organization’s technical 

programs and the organization’s ability to achieve its stated objectives? 

3. Assess the adequacy of the organization’s facilities, equipment, and human resources. 

 How well do the facilities, equipment, and human resources support the organization’s technical 

programs and its ability to achieve its stated objectives? How could they be improved? 

4. Assess the effectiveness by which the organization disseminates its program outputs. 

1

 The six NIST laboratories are the Engineering Laboratory, the Physical Measurement Laboratory, the 

Information Technology Laboratory, the Material Measurement Laboratory, the Communication Technology 

Laboratory, and the NIST Center for Neutron Research. 
7 

 How well are the organization’s research programs driven by stakeholder needs? 

 How effective are the technology transfer mechanisms used by the organization? Are these 

mechanisms sufficiently comprehensive? 

 How well is the organization monitoring stakeholder use and impact of program outputs? How 

could this be improved? 

The context of this technical assessment is the mission of NIST, which is to promote U.S. 

innovation and industrial competitiveness by advancing measurement science, standards, and technology 

in ways that enhance economic security and improve the quality of life. The NIST laboratories conduct 

research to anticipate future metrology and standards needs, enable new scientific and technological 

advances, and improve and refine existing measurement methods and services. 

 NIST specified that 5 of the 10 divisions of the PML would be reviewed—Quantum 

Measurement Division, Radiation Physics Division, Microsystems and Nanotechnology Division, 

Nanoscale Device Characterization Division, and Sensor Science Division. The following PML divisions 

were not reviewed because they had previously been reviewed (NIST may request their review in the 

future): Applied Physics Division, Quantum Electronics Division, Quantum Physics Division, Time and 

Frequency Division, and Weights and Measures Division. In order to accomplish the assessment, the 

National Academies assembled a panel of 24 volunteers whose expertise matches that of the work 

performed by PML staff.2

 

 On May 17-20, 2021, the panel conducted a virtual review (via Internet media). During a plenary 

session, the panel received overview presentations by the acting NIST Director and the director of the 

PML. Subsequently, the panel spent approximately 1.5 days receiving presentations from and engaging in 

discussions with the staff at the five divisions reviewed. On the third day, the panel met in a closed 

session to deliberate on its findings and define the contents of this assessment report. The panel met with 

NIST management on the fourth day to clarify open questions. 

 The panel’s approach to the assessment relied on the experience, technical knowledge, and 

expertise of its members. The panel reviewed selected examples of the technical research performed at 

PML; because of time constraints, it was not possible to review PML programs and projects exhaustively. 

The examples reviewed by the panel were selected by PML. The panel’s goal was to identify and report 

salient examples of accomplishments, challenges, and opportunities for improvement with respect to the 

factors suggested above by the NIST Director. These examples are intended collectively to portray an 

overall impression of the laboratory, while providing useful suggestions specific to the projects and 

programs that the panel examined. The panel applied a largely qualitative rather than quantitative 

approach to the assessment. 

 Given the necessarily broad and non-exhaustive nature of the review, omission in this report of 

any particular PML program or project should not be interpreted as implying any negative reflection on 

the omitted program or project. Because the divisions reviewed by the separate teams address separate 

specific missions and tasks, the type of information provided by each division was inconsistent with 

respect to some metrics. The lack of discussion of a metric, such as publications, in one division but not 

another should not be taken as an indication that there was a difference in performance on the given 

metric between the divisions. 

2

 See on the NIST Physical Measurement Laboratory homepage for information on organization and programs 

at https://www.nist.gov/pml accessed May 17, 2921. 
8 

2 

Quantum Measurement Division 

The mission of the Quantum Measurement Division is to provide the foundation for the 

International System of Units (SI), test its limitations, and develop the measurement infrastructure to 

disseminate SI units related to electrical and mechanical properties. The Quantum Measurement Division 

covers a wide breadth of interests, including fundamental science and everyday needs and applications. 

The division’s strategic goals are to explore fundamental aspects of the quantum nature of light and 

matter; develop quantum metrology and the Quantum SI; create the foundations for electrical, mass, and 

force metrology from first principles; deliver improved measurement services; and disseminate critically 

evaluated atomic reference data. 

The division is organized into the following six groups: the Atomic Spectroscopy Group; 

Quantum Optics Group; Laser Cooling and Trapping (LCT) Group; Fundamental Electric Measurements 

Group; Applied Electrical Metrology Group; and Mass and Force Group. Many staff from the Quantum 

Optics Group and all staff from the Laser Cooling and Trapping Group are participants in the Joint 

Quantum Institute (JQI) and the Joint Center for Quantum Information and Computer Science (QuICS),

both located on the University of Maryland campus. All of the groups, except the Fundamental 

Constants/CODATA (Committee on Data for Science and Technology) Center group, were reviewed by 

the panel. 

TECHNICAL QUALITY OF THE WORK 

 The accomplishments of the division’s groups are many and significant. 

The work of the Atomic Spectroscopy Group’s experimental team includes the spectroscopy of 

highly charged ions and high-resolution precision spectroscopy of atomic lines. Among the group’s 

accomplishments are applications of newly developed calorimetric sensors recently developed by PML’s 

Quantum Electrodynamics Division that offer ultrawide bandwidth at an excellent resolution similar to 

crystal spectrometers. The Atomic Spectroscopy Group collaborates actively and effectively with several 

university groups. 

The Quantum Optics Group addresses a wide variety of topics. On the applied side, these include 

single-photon detectors with improved time resolution, integrated single-photon sources on a chip, and 

studies of biophotonics at the single-photon level. On the fundamental side, the Quantum Optics Group 

studies important questions such as quantum metrology beyond the classical limits and possible 

implementations of secure quantum communication in a future quantum network. The group is 

undertaking a significant theoretical effort toward understanding fundamental aspects of entanglement 

propagation in many-body systems, in particular in systems with long-range interactions. Other 

noteworthy theoretical work includes quantum-enabled novel detectors for searching for the elusive dark 

matter and new physics beyond the Standard Model. Staff from this group also contributed significantly 

to the Quantum Economic Development Consortium (QED-C), which seeks to align research in the 

quantum field with industry needs. 

The Laser Cooling and Trapping Group works on fundamental research at the intersection of 

atomic, molecular, and optical physics, condense-matter physics, and quantum information science. A 

unifying theme across these different subfields is the study of coherent quantum phenomena. The research 
9 

programs are driven by the need to understand quantum physics in the context of information science and 

the importance of developing approaches to exploit quantum physics for new technologies. The scientific 

work of this group is well aligned with the National Quantum Initiative Act, and the research outcomes 

are important to the broader quantum ecosystem across the world. 

The LCT Group’s research portfolio is wide-ranging and includes some of the best programs in 

the world on ultracold atom physics and quantum many-particle physics. Ultracold atoms, created via 

laser cooling and trapping, provide a powerful platform for quantum simulation. Quantum simulation is 

one of the central applications of quantum information science and involves tuning one quantum system 

to behave like another. This group has pioneered methods to study new and exotic many-particle quantum 

states relevant to solids using optical-lattice quantum simulators. The work on topological order has 

spawned new research programs around the world and driven the field forward. The LCT Group is also at 

the forefront of new technical developments, including sub-wavelength microscopy in optical lattices and 

applying modern machine learning to optimize the experiments and analyze data. The methods are 

extremely useful to others in the field. Group members have also pioneered the development of 

approaches to create superfluid circuits and analogues of the expansion of the early universe using lasercooled, ultracold atomic gases. 

The LCT Group also studies quantum optics and produces some of the best results in this area in 

the world. Quantum optics is important to creating new devices. A key accomplishment is the 

demonstration of a high-fidelity, narrow-band photon source and demonstrating interference from photons 

produced using different species of laser-cooled atoms. This hybridization of two types of atoms and 

photons at different wavelengths could provide an important platform for devices needed to develop and 

deploy quantum networks. This group is also at the frontier of nonlinear optics and has produced 

important results on using atomic systems to produce correlated states of light. These quantum states can 

be used to improve interferometric measurements. 

The LCT Group has a strong theory component that supports activities around the world and the 

development of new metrology instruments. Key contributions include atomic-structure calculations, 

which are needed at the frontier of laser cooling and trapping research and are critical to the development 

of next-generation, optical-lattice clock standards. The group also computes collision properties of atoms 

and molecules that are critical for the cold-atom vacuum sensor, which is a unique project to provide an 

absolute standard for ultra-high vacuum pressures. The work of the LCT Group is well aligned with the 

National Quantum Initiative Act and positions the team to capitalize on opportunities for scientific 

collaboration with, for example, The National Science Foundation‘s (NSF’s) Quantum Leap Challenge 

Institutes and the Department of Energy’s (DOE’s) National Quantum Initiative Centers. 

The Fundamental Electrical Measurements Group provides the foundation of the nation’s 

electrical infrastructure through measurement services in the general areas of resistance, impedance, and 

related quantities. As part of its mission, the group maintains an active research program in precision 

measurements based on fundamental constants and in the development of quantum electrical standards. 

The group’s laboratory program is competitive with other top-level, similarly focused national 

measurement institute (NMI) groups worldwide. Among the most notable achievements, the group had a 

significant role in the redefinition of the kilogram, leading to the official redefinition of the SI on May 20, 

2019. Part of this contribution came in the form of the internally developed Kibble balance, which 

brought together many disciplines inside the PML to measure the Planck constant to an astonishing 

accuracy. 

Another major innovation, the transition from a GaAs to a graphene implementation of the 

Quantum Hall Resistance Standard (QHR) has resulted in superior performance, a smaller footprint, and 

lower build cost. This has enabled industry partners to commercialize these types of instruments. As a 

necessary step in building the graphene QHR, the group developed and optimized in-house graphene 

production. This helps further support commercialization of the QHR. A measurement traceability link 

from the QHR to the Calculable Capacitor has been established, adding additional confidence to the 

evaluated performance of both measurement standards. 
10 

The Applied Electrical Metrology Group supports the nation’s infrastructure by providing 

calibration services in the general areas of AC and DC voltage, current, phase, and power. As part of this 

mission, the group maintains an active research program in precision measurement systems based on 

quantum voltage standards to support calibration services within the group. 

The Applied Electrical Metrology Group is competitive with similar groups at other top-level 

NMIs. The group has advanced the performance of electrical standards beyond any peers within the field. 

The Group utilizes a Josephson-junction based arbitrary waveform synthesizer (JAWS), developed by 

PML’s Quantum Electrodynamics Division, that continues to increase output range while lowering costs 

and physical footprint. New thermal voltage converters have been developed and added to the Standard 

Reference Instrument (SRI) catalog. Research has started on a new nano-photonic thermal converter that 

may lead to a self-calibrating device with a zero-traceability calibration chain. Development of a 

metrology-grade radiofrequency (RF) buffer amplifier could lead to greater accuracy in AC current and 

RF measurement areas. 

With the new definition of the kilogram and the realization of its consensus value, the Mass and 

Force Group is faced with a number of new challenges. The application of the new kilogram, its 

realization and dissemination, involves a number of steps ranging from the realization of a high-precision 

mass comparator, the calibration of standards in vacuum, the transfer from vacuum to air, the 

establishment of working standards under atmospheric pressure, and the dissemination of mass scales. 

Noteworthy are a rolling vacuum system designed to transfer weights in high vacuum between stations, 

and a unique magnetic suspension mass comparator that is essential for the transfer of mass realizations 

from their vacuum environment to air, with a demonstrated standard uncertainty of 15 micrograms. 

 The Mass and Force Group also develops an electrostatic force balance that provides a link 

between milligram-scale masses and the Planck constant. This approach is superior to the alternative of 

determining small masses by comparing them directly to the kilogram, in which case the associated 

subdivision of mass process results in accrued uncertainty. The electrostatic force balance approach 

promises orders-of-magnitude reduction in the uncertainty of masses at the microgram level and could 

possibly be miniaturized for implementation in a NIST-on-a-chip (NOAC) device. 

The photon momentum yields a fundamental relation between mass, force, and laser power that 

can be used for laser power metrology and force measurements. A miniaturized version of this system 

using calibrated weights could provide a self-contained NOAC force reference for femtonewton 

resolution. Small-mass and small-force metrology, in particular in connection with NIST-on-a-chip, offers 

considerable potential for synergy and cross-fertilization, also with groups with related interest at NISTBoulder. 

TECHNICAL EXPERTISE OF THE STAFF

All the groups have the scientific and engineering staff with the appropriate level of expertise to 

deliver on their mission. In particular, the technical expertise of the staff in the Quantum Measurement 

Division is outstanding. The Quantum Optics and LCT Groups are among the best in the world, and their 

research is at the worldwide forefront of the field. The nearly equal mix of researchers in theory and 

experiment in the LCT Group is a unique strength that drives the research forward. 

The quality of the staff has been recognized by a number of prestigious awards. Recent recipients 

of federal awards include eight awardees of Gold Medals and three awardees of Bronze Medals of the 

U.S. Department of Commerce, one recipient of a Presidential Early Career Award, and a Presidential 

Rank Award. External awards include an Arthur S. Flemming Award and an Arthur S. 

Flemming/Katherine B. Gebbie Lifetime Achievement Award; a George Snow Award; an International 

Union of Pure and Applied Physics Young Scientist Prize in Atomic, Molecular, and Optical Physics; and 

a Clarivate Analytics recognition for highly cited researcher. 
11 

ADEQUACY OF RESOURCES 

The Quantum Optics and LCT Groups have the appropriate level of scientific expertise to deliver 

on their mission. A strength of the Quantum Optics and LCT Groups is their integration with the JQI, 

which includes 15 NIST principal investigators (PIs) out of 32 research staff, with about 40 graduate 

students working with NIST JQI Fellows. This association enables the NIST researchers to have easier 

access to students on the University of Maryland campus. The JQI also brings together researchers from 

different subdisciplines, which has led to new and productive directions for the laser cooling and trapping 

program. With their wide-ranging interests, they are well-positioned to take advantage of collaborations 

and new funding opportunities in the field. This is particularly easy for NIST researchers who also have 

adjoint faculty status at the University of Maryland through JQI. 

On the flip side, a substantial part of the research effort of the Quantum Optics and LCT Groups 

has migrated to the University of Maryland campus, and the resulting geographical separation from NIST 

can lead to isolation. This issue is mitigated by former students and postdoctoral researchers who become 

permanent NIST employees and drive collaboration. Lessons learned from the COVID-19 pandemic 

about remote work have also been beneficial in addressing this issue. 

On the financial side, The JQI was supported for 10 years as a NSF Physics Frontier Center. The 

program was not renewed. This loss provides a challenge to financially supporting the research effort, 

although the loss of NSF Physics Frontier Center funding is an opportunity to explore new research 

directions. The LCT Group is highly aligned with the National Quantum Initiative Act and well 

positioned to capitalize on new federal funding programs in this area. 

The JQI research facilities on the University of Maryland campus are among the best in the world 

but are at physical capacity. Expansion space is needed for the research programs to grow and remain at 

the frontier. The facilities at the NIST Gaithersburg site have significant deferred-maintenance issues. A 

recent air-handling failure significantly disrupted research progress. 

The Fundamental Electrical Measurements Group has the facilities, equipment, and human 

resources to support the stated objectives of the organization’s technical program. However, because of 

the COVID-19 pandemic and the resulting closures and limited physical capacities, the facilities’ 

malfunctioning HVAC systems have been a source of issues that are blocking progress. 

The Applied Electrical Metrology Group has the facilities and equipment to support the stated 

objectives of the organization’s technical program. However, it suffers from a shortage of available 

human resources to support the group’s calibration services. Some of the less central activities appear to 

be understaffed. The flood damage to the Kibble balance laboratory is problematic. 

The Atomic Spectroscopy Group is somewhat understaffed, considering the scope, importance, 

and broad application of its task serving a wide variety of stakeholders from industry, with applications in 

fundamental science. Critical issues include difficulties hiring, given the small numbers of students 

trained in spectroscopy at universities, and knowledge transfer when experienced staff retire. There is also 

a shortage of available human-resource support for the group’s calibration services, on which DOE, the 

Department of Defense (DoD), NASA, and the commercial industry rely heavily The Group does not 

have sufficient resources to meet demand for multijunction thermal converters (ac/dc voltage converters). 

 A hiring challenge is that there is no broad university training for metrologists, who need to 

understand basic science and engineering. Few universities offer this kind of training. The alternative 

solution of working with short-time visitors does not help with maintenance continuity and corporate 

memory. 

The excellence and worldwide reputation of a number of staff members of the Quantum 

Measurement Division result in significant recruitment efforts and attractive job offers by top universities 

and research institutes. It speaks highly for NIST that it has been largely successful in countering these 

offers and retaining these superstar researchers. 
12 

EFFECTIVENESS OF DISSEMINATION OF OUTPUTS 

The Atomic Spectroscopy Group generates, critically evaluates, maintains, and distributes atomic 

spectroscopy data. It serves a broad community that includes astronomy, chemistry, and extreme 

ultraviolet (EUV) lithography. The NIST Atomic Database is unique in the world in that it enables a 

critical evaluation of published data to compile a database. 

The Quantum Optics and LCT Groups disseminate products via publication in peer-reviewed 

journals and at scientific conferences. The publication rate is strong, and results appear in top journals 

with high impact factor. Many of the publications are frequently cited in the field, which demonstrates the 

importance of the fundamental and applied research performed at NIST. The LCT Group also plays an 

important role in collating data on precision measurements to improve knowledge of the fundamental 

constants of nature and on quantum neutron interferometry at the NIST Center for Neutron Research 

(NCNR). 

The Fundamental Electrical Measurements Group has outputs in the form of publications in peerreviewed journals and at scientific conferences, and in-house manufactured standards in the form of 

resistors, scaling resistors, and intrinsic QHR systems. Although still costly, the recent development of 

graphene-based QHRs has halved the cost of the previous GaAs-based version. The operation cost will 

also be reduced due to using a closed-loop cryostat that replaces the need of buying liquid helium, a 

limited resource. Overall, this group serves as an excellent example of balancing the need to research and 

develop the latest technologies with working with industry to produce practical, cost efficient, standards. 

The Applied Electrical Metrology Group has also developed many robust standards that are sold 

to government and commercial customers through the SRI program. The Group serves as an excellent 

example of turning research into actual, practical, useful technology that benefits industry. However, 

success at offering a state-of-the-art standard at a price below similar commercially available standards 

has pushed demand beyond what the group can supply. Other outputs of the Applied Electrical Metrology 

Group include publications in peer-reviewed journals and at scientific conferences. 

The Mass and Force Group disseminates its results in the form of publications in peer-reviewed 

journals and at scientific conferences and in-house development and measurement of standards. The 

group also represents U.S. interests in national and international metrology communities through 

participation in and leadership of consultative committees, working groups, and standards organizations. 

The establishment of the Quantum SI, and in particular the introduction of the new mass standard 

in terms of Planck’s constant, was accompanied by an outstanding range of outreach and educational 

activities, including in particular the NIST do-it-yourself LEGO® Kibble balance, which permit a broad 

audience of students and science enthusiasts to build their own working Kibble balances out of LEGO® 

bricks. Noteworthy also are the superb lectures by Nobel Laureate W.D. Phillips explaining the Quantum 

SI revolution to broad audiences worldwide. 

GENERAL CONCLUSIONS AND RECOMMENDATIONS

 

The activities of the Quantum Measurement Division cover a remarkably wide range of topics, 

including basic research on the foundations of quantum measurements and quantum information science, 

and their applications to the redefinition and Mise en Pratique of the Quantum SI. The division provides 

critically evaluated spectroscopic data important for broad areas of science and technology and conducts 

fundamental and applied research toward the development of electric standards. Division staff is highly 

qualified. It compares favorably with the best groups worldwide working on related areas, and in a 

number of activities it is truly world leading. Generally, the division effectively disseminates the results 

of its work; the Applied Electrical Metrology Group could improve the transfer to industry partners of the 

technology it develops. 

The most significant highlight of the Quantum Measurement Division is its key role in an 

achievement of historical importance, namely, the establishment of a revised SI unit in 2018. Central to 
13 

this paradigm shift away from a mass artefact was the development of a Kibble balance that exploits 

fundamental electrical metrology: the quantum voltage characteristic of the Josephson effect and the von 

Klitzing resistance characteristic of the quantum Hall effect. In this way, the Kibble balance realizes a 

new definition of the kilogram based solely on fundamental constants. The resulting mass standard 

replaces the International Prototype of Kilogram, a cylinder of platinum-iridium which had served as the 

standard unit of mass of the metric system ever since 1899. As a result, all SI units have now been put on 

a fundamental, prototype-free footing and are now defined by giving exact numerical values to seven 

fundamental constants: the speed of light, the hyperfine transition frequency of Cesium atoms, the Planck 

constant, the electron charge, the Boltzmann constant, the Avogadro number, and the luminous efficacy. 

This development is having a profound impact on many of the programs of the Quantum Measurement 

Division of NIST. In particular, the Mise en Pratique and distribution of the new mass standard requires a 

number of novel steps that are currently being successfully developed by the group. 

The division played a pivotal role in the establishment of the National Quantum Initiative Act and 

the Quantum Economic Development Consortium. In terms of measurement devices and standards, 

noteworthy is the development of the new graphene-based quantum Hall standard that operates at higher 

temperatures and smaller magnetic fields than the GaAs standard. Regarding new quantum technologies, 

significant achievements have been the development of an integrated single-photon source with a rate of 

20 million photons per second; the development of a quantized arbitrary waveform synthesizer that can 

produce fundamentally accurate signals; and the generation, critical evaluation, and maintenance of an 

essential and widely used atomic spectroscopic database. 

Aging facilities are suffering from delayed maintenance or urgent maintenance interrupted by the 

COVID-19 pandemic. 

RECOMMENDATION: The Quantum Measurement Division should continue to pursue 

resources needed to address deferred maintenance, including air-handling issues, for the 

Advanced Measurement Laboratory Complex on the NIST Gaithersburg campus, and to 

repair the flood damage to the Kibble balance laboratory. 

The division is experiencing difficulty in recruiting, especially in areas where universities do not 

provide a training ideally matched to the division’s needs. Most undergraduate students are not aware of 

the broad range of science and engineering opportunities at NIST. Graduate students are not generally 

aware of the research opportunities and permanent positions that NIST offers. Attending campus 

recruiting events, giving seminars within university departments, and connecting with the Quantum Leap 

Challenge Institutes, DOE National Quantum Initiative centers, and other center-scale programs could 

provide a pathway to higher visibility 

RECOMMENDATION: The Quantum Measurement Division should become more 

proactive in outreach to universities with a goal of developing a recruiting pipeline. 

 No plan was presented to the panel for improving the NIST Calibration Services, which is a 

unique service that NIST provides to industry. NIST is the sole provider of calibrations that are directly 

compared to U.S. national standards, and the service has been stagnant with diminishing quality over the 

last decade. Division staff attribute this to external budget cuts and loss of support personnel. 

RECOMMENDATION: The Quantum Measurement Division should collaborate with 

other NIST organizational units in analyzing, assessing, and rejuvenating the NIST 

Calibration Services. 
14 

3 

Radiation Physics Division 

The mission of the Radiation Physics Division is to develop, maintain, and disseminate the 

national measurement standards for ionizing radiation and radioactivity, and methods and models needed 

to address related applications. The goal of the division is to provide accurate measurement in service to 

industry and in related basic science essential to its mission as the nation’s precision measurement 

laboratory. The division provides a unique resource to the United States based on its one-of-a-kind 

facilities and expertise housed within its component groups—the Dosimetry Group, Neutron Physics 

Group, and Radioactivity Group. 

TECHNICAL QUALITY OF THE WORK

The dosimetry program primarily serves stakeholders in radiation protection, industrial radiation 

processing, national security, and therapeutic and diagnostic medical physics, fundamentally supporting 

required calibrations and quality assurance of nationally mandated programs and efforts. A key mission of 

the dosimetry program is to develop and maintain national air kerma (kinetic energy released per unit 

mass), air kerma rate, and absorbed-dose calibration standards based on the derived International System 

of Units (SI) unit—the gray—for homeland security, medical, radiation processing, and radiation 

protection applications. This is accomplished through the provision of calibration services utilizing the 

dosimetry of kilovolt (kV) and megavolt (MV) X rays; 137Cs and 60Co gamma rays; 90Sr/Y and 85Kr beta 

particles; 125I, 103Pd, 131Cs, 192Ir, and 137Cs brachytherapy; and electron beam sources and measurement 

instruments. 

The quality of the work conducted by the Dosimetry Group is excellent, as demonstrated by the 

streamlined practices for maintaining the existing radiation dosimetry standards while anticipating new 

approaches to meeting calibration standards in emergent and in-demand fields such as brachytherapy 

calibration and electron beam calibration. While the activities are predominantly service-oriented, 

meeting calibration needs for critical programs and activities supported by associated regulations, the 

group has demonstrated technical accomplishments in designing and building a new therapy-level, 

gamma-radiation dosimetry calibration facility that improves NIST’s ability to deliver state-of-the-art 

measurement capabilities for air kerma and absorbed-dose-to-water calibrations to a wide stakeholder 

base, and in pioneering research and development of new objective methods to assess image quality in 

security X-ray systems. 

The Dosimetry Group has performed detector calibration for homeland security systems, as well 

as occupational-radiation areas, survey, and personnel dosimetry capabilities using a highly reproducible 

(~0.1%) 137Cs irradiator source as established by the National Council on Radiation Protection and 

Measurements (NRCP) Report 160, making this facility critical across multiple national mission areas. 

The Dosimetry Group is further tasked with fulfilling the American Association of Physicists in Medicine 

(AAPM) Task Group 56 recommendation that all brachytherapy sources be directly traceable to NIST by 

automating the Wide-Angle Free-Air Chamber, to measure key quantities in the calibration process of 

radioactive material in brachytherapy seeds (i.e., air-kerma strength, well ionization chamber response, 

photon energy fluence spectrum, air-anisotropy ratio, and radiochromic film contact exposure). The 

culmination of these processes ensures accurate clinical dosimetry while maintaining the dosimetric 
15 

traceability of these sources, enabling the three accredited dosimetry calibration laboratories (ADCLs) to 

maintain secondary, NIST-traceable standards. In the support of medical dosimetry standards, the 

bilateral benchmark activities between NIST and the Bureau International des Poids et Mesures (BIPM) 

has ensured harmonization of air kerma and absorbed dose standards with high fidelity, resulting in 

journal publications. Interest expressed by the group in improving the state of the art in nano-sensor and 

microchip dosimetry beyond long-established alanine-based, EPR-based (electron paramagnetic 

resonance–based) methods, resulting in two patents, demonstrates research interests that could 

beneficially be conducted collaboratively with the NIST-on-a-chip (NOAC) initiative. 

The Dosimetry Group primarily works with its large stakeholder community. Alternative 

mechanisms other than radiological-based calibrations using 137Cs and 60Co could be applied, given 

movements to non-radiological source calibration in-field, thereby aligning calibration with field 

practices. Calibration and measurement associated with new modalities in medical physics (e.g., proton 

and heavy-ion therapy), with associated facilities and staffing expertise, are absent in the established 

activities of the group, and these capabilities need to be anticipated. While current calibration services 

harness established techniques, active research engagement is critical to ensure integration of new 

technologies that will supersede current methods and equipment. In addition to seeking extramural 

funding, the division could leverage initiatives such as NOAC in, for example, EPR dosimetry research. 

The neutron physics program is at the forefront of neutron measurement science. It maintains 

facilities and capabilities that are unique in the United States and, in many cases, on par with the premier 

neutron institutes around the world. The single-crystal neutron interferometry facility at NIST is the only 

one in the United States and has achieved the best phase contrast in the world. The neutron/X-ray 

tomography (NeXT) imaging facility is the world’s best for offering simultaneous tomography with 

neutrons and X rays. The neutron beam line at the NCNR, used by the Neutron Physics Group, is the 

preeminent resource for cold-neutron fundamental physics in the United States, and the group is 

pioneering the measurement of the neutron lifetime using the beam method (to be compared to the bottle 

method, thereby resolving the neutron lifetime puzzle). The NG-C beamline, after the planned 

cold0source upgrade in 2023, will increase the neutron flux by a factor of two; it might be the only highflux beamline available to users in the United States, because the fundamental neutron physics beamline 

at the Spallation Neutron Source at the Oak Ridge National Laboratory will be dedicated to the nEDM 

(neutron electric dipole moment) experiment. In addition to the neutron flux calibration services, the 

group is carrying out a diverse research program, including fundamental physics, nuclear power 

monitoring, national security, manufacturing, and radiation protection. 

The Neutron Physics Group has improved the technique for calibrating neutron flux. The group 

has been operating a MnSO2 bath to calibrate neutron source emission rate for a variety of radioisotopic 

sources (with up to 1010/s and 0.8% precision). With it, all U.S. neutron metrology is traceable to a 

reference source, NBS-1, maintained by NIST. Over the past decade, the Neutron Physics Group 

developed an Alpha-Gamma device to improve the neutron metrology precision to 0.06%. This expertise 

in neutron flux calibration directly supports the basic science program to measure the neutron lifetime 

(and other beta-decay observables) using the cold-neutron beams at the NCNR to test the standard model 

of particle physics and Big Bang nucleosynthesis. The recent work on the Alpha-Gamma device improves 

the knowledge of the neutron capture cross-section on 6

Li to 0.3% precision, with an ongoing effort to 

improve the neutron capture cross-section on 235U to 0.2% and other isotopes relevant to nuclear sciences 

and national security. 

 The neutron imaging program supports applied research on hydrogen fuel cells, energy storage, 

and porous media in geology and other civil engineering materials (like concrete). The thermal neutron 

imaging station (BT2) is fitted with an X-ray system, making it the world’s first such facility. The 

simultaneous tomography of neutrons and X rays enhances the capabilities to resolve small features, 

which is critical to studying material degradations and lithium-ion transport in batteries. A new cold 

neutron imaging instrument, installed in 2015, enables studies of magnetic structures using polarized 

neutrons and four-dimensional (4D) tomography to reach a spatial resolution on the micron scale. The 

ongoing effort to develop Wolter optics and a neutron imaging far-field interferometer, with a large 
16 

acceptance of neutron flux, will reduce the exposure time by a factor of 1,000 while achieving high 

resolutions in both space and time. 

Neutron interferometry provides a versatile tool to probe new knowledge, including nuclear 

physics and characterization of quantum materials. It uses the interference of matter-waves of the neutron 

to probe the four fundamental forces of nature with high precision. Recent work includes high-precision 

measurements of the scattering length of n-4

He (0.06% precision, 2020), the neutron charge radius, and 

the creation of entangled neutron states (spin and orbital angular momentum) to characterize quantum 

materials. Ongoing development of far-field interferometry using nanofabricated phase diffraction 

gratings aims to probe the weak gravitational force to extract the fundamental constant “G” using single 

neutrons with a precision comparable to the torsion balance–based experiments. 

To support the NIST mission relating to neutron calibrations and metrology, the group members 

are developing new neutron detectors. Recent work includes a photon-assisted neutron detector (PhAND; 

U.S. patent) and segmented fast-neutron detectors to meet the national needs for fastneutrons dosimetry in 

homeland securities, underground sciences, and health physics. This expertise in fast-neutron detection 

enables the Neutron Physics Group to address the needs of a reactor-based neutrino experiment, 

PROSPECT (Precision Reactor Oscillation and Spectrum experiment), which measures the flux and 

energy spectrum of neutrinos from the high-flux isotope reactor fission reactor, with a highly enriched 

uranium fuel, to search for the sterile neutrinos, which are theoretically new particles. 

The Radioactivity Group’s key mission is to develop and maintain radiation detection methods, 

often based on first-principles methodology, that directly measure radioactive emissions. The group is 

required to develop relevant standards and methods of assay for industrial and medical radioisotopes. The 

group defines protocols for measurement of radioactivity on the national and international level and for 

other government agencies such as the Nuclear Regulatory Commission, the Department of Homeland 

Security, and the Food and Drug Administration, frequently linking radioactivity measurements to NIST 

standards. 

Since the advent of the nuclear era, the use of radioactive isotopes has brought tremendous 

benefits to society in a multitude of ways, from expanding our knowledge of the world around us to 

improving the lives of millions of people through medical diagnoses and treatment. The use of radioactive 

isotopes has allowed researchers to answer a myriad of questions about wide-ranging subjects, from the 

behaviors of ancient peoples to the movement of carbon through the environment. The use of radioactive 

materials by industry allows the analysis of material densities, the inspection of critical systems, product 

sterilization, and oil and gas exploration. In health care, radioisotopes have been instrumental in 

diagnosing and treating disease, improving the lives of millions of people. One isotope alone (technetium99m) is used in over 16 million people per year in the United States as an imaging agent. 

TECHNICAL EXPERTISE OF THE STAFF

The staff of the Dosimetry Group is distributed among core expertise areas in accelerator physics, 

computational dosimetry, high-dose dosimetry, X-ray dosimetry, gamma-ray dosimetry, 

calorimetry/photonics, and brachytherapy. 

The scientific expertise in the Neutron Physics Group is evidenced by its success in several areas 

of activities. The area of calibration and metrology includes neutron source calibrations, absolute neutron 

fluence, standard cross-sections for thermal neutrons, and high-dose irradiation with neutrons. The area of 

basic physics research includes fundamental neutron physics, interferometry, and reactor neutrinos. The 

area of applied research includes neutron imaging, polarized 3

He spin filters, neutron detection, 

dosimetry, and spectroscopy. The caliber and expertise of the staff in all activities and at all levels is 

outstanding. Four of the staff have been recognized as fellows of the APS. Senior staff members are 

leading the standardization of precision measurements in neutron sciences in the United States. 

There is strong synergy among the groups in calibrations and metrology, basic sciences, and 

applied research, with the staff supporting multiple areas of the program. In particular, the neutron 
17 

imaging program supports many leading industrial research and development program, s as evidenced by 

the impressive numbers (approximately) of unique experiments (416), patents (40), papers (200), and 

Ph.D. dissertations (66) since its inception. The basic research program on beta-decay physics involves a 

handful of difficult measurements; each takes multiple years of data collection to acquire the counting 

statistics and to perform many checks on systematic effects, which also requires running times of 

comparable lengths. The interferometry program has developed a versatile tool that produces significant 

scientific results. Several high-impact publications, many with external university collaborators, showcase 

the unique niche of this approach. The 3

He laboratory continues to support the fundamental neutron 

physics and neutron scattering programs in the NCNR by providing state-of-the-art large vapor cells to 

polarize cold neutrons. 

The Radioactivity Group leads the nation in the development of new methods and instruments for 

determining the absolute activity of a radionuclide or mixture of radionuclides. The group is publishing 

and disseminating information on new approaches for determining the absolute activity of a radionuclide, 

and the group is fulfilling its mission of advancing measurement science and providing standards for the 

use of radioactive materials in medicine and industry. 

The Radioactivity Group continues to develop new methods for creating primary radioactive 

standards. This includes live-timed 4παβ-γ anti-coincidence counting and Monte Carlo simulation 

analysis. The group is part of a NIST Innovations in Measurement Science–funded proposal to develop 

leading-edge technology that can be used to determine the absolute activity of a mixture of radionuclides 

using 4π decay energy spectrometry with ultracold transition edge sensors. In the area of medical 

applications, the group developed a methodology for calibrating Ge-68 activity content in a commercially 

available calibration source that is traceable to a national standard for positron emission tomography 

isotopes, and it developed standards for the complex decay chain targeted-alpha therapy radioisotopes Ra223 and Ra-224. 

ADEQUACY OF RESOURCES

Maintenance of facilities and infrastructure is a necessary foundation for mission 

accomplishment, as exemplified by the modernization project for Building 245, one of the world’s 

premier laboratories for ionizing radiation measurement science and research. Recent infrastructure 

upgrades have increased efficiency of operations, with fewer interruptions in calibration service work due 

to environmental conditions (e.g., temperature and humidity stability in air kerma–based standards and 

calibrations). Investment in critical facility improvements in X-ray calibration, relocation of the 60Co 

source for medical dosimetry standards, building a new high-dose-rate brachytherapy vault, and 

upgrading to 10 MeV the electron beam accelerator used in industrial irradiation processes are all 

demonstrated commitments to facility modernization and sustainability. Movement to new H-wing 

laboratories dedicated to general dosimetry calibration activities is under way; these activities include 

photon and electron, brachytherapy, and radiation-processing dosimetry facilities and instruments, 

collocated with mechanical and electronics shops. 

The Building 245 modernization project has imposed demands on division finances and 

resources, which has detracted from staff time and regular duties (e.g., moving equipment and escorting 

construction workers). It will be necessary to anticipate the impacts on resources, staffing, and budget to 

mitigate interruption of activities during (1) the migration to facilities in the new H-wing; (2) the move to 

a renovated laboratory in the existing building for the EPR dosimetry facility; (3) renovation in place for 

the A-wing medical industrial radiation facility (MIRF) and 10 MeV industrial accelerator, scheduled in 

the 2022-2024 timeframe; and (4) renovation of the B-wing 137Cs and 60Co radiation protection, 

accelerator, and high-dose calibration facilities in a currently undetermined timeframe. 

The Neutron Physics Group occupies two research buildings. In the NCNR, it is running eight 

neutron beam lines and the thermal column; in Building 245, there are several laboratories, including the 

Mn (manganese) bath room, the polarized 3

He laboratory, a low-scatter room for dosimetry, and a 
18 

machine shop. The decaying infrastructure of the neutron calibration and setup laboratories in Building 

245 is being renovated. The renovation, however, presents a major challenge to all operations, with an 

uncertain timescale for completion. In the NCNR, the high-flux neutron beam lines, the imaging stations, 

and the interferometry facilities are the best in the world. However, the COVID-19 lockdown in 2020, 

followed by a recent safety incident in the NIST reactor, triggered by an over-temperature of one fuel rod, 

prevented the reactor from coming online and had disruptive impacts on the neutron physics programs. 

Delays associated with the planned cold source upgrade in 2023 will inevitably reduce the scientific 

productivity of the group. 

In the Dosimetry Group often one dedicated staff member is assigned to each of the core areas; 

mitigating this reliance on a single individual could improve capacity for performing mission-critical 

work and additional research. The training program that involves students and postdoctoral researchers in 

each of the critical standards activities could be strengthened. Fostering a program to share equipment and 

facilities with users at national laboratories and universities would be useful. It will be important to ensure 

sustainability of succession planning and knowledge retention by prioritizing allocation of resources in a 

manner that appropriately addresses the requirements of human capital development and infrastructure 

improvements. 

Research staff in the Neutron Physics Group are world-leading experts in neutron measurement 

sciences. However, considering the large scope of work, loss of staff, and difficulty hiring replacements, 

there will be a challenge in sustaining an adequate level of staffing. The group lost several senior staff 

members recently due to departure and retirement, but there is no plan to replace them, due to budgetary 

constraints. Understaffing has significantly increased the service-base workload of current staff in order to 

meet the NIST mission. As such, Ph.D.-level scientists are deprived of time and opportunities for doing 

innovative research. Many recent and current postdoctoral researchers have demonstrated credentials to 

do outstanding science; however, the group reported that there is apparently no funding available to retain 

and promote them at NIST. Currently, the National Academies/National Research Council (NRC) 

postdoctoral program is the main channel for the group to recruit postdoctoral fellows, but there is 

significant competition among the sciences represented by the applicants and the selection committees. 

The understaffing situation remains the major risk to the program to meet its core missions while pushing 

the advancement of neutron metrology. Without increasing the number of staff, NIST risks losing its 

leadership role and its competitiveness with other neutron facilities in the United States and around the 

world. 

The Radioactivity Group has successfully moved multiple detection systems to the new 

laboratories in the H-wing. The group has demonstrated that these unique instruments with over 40 years 

of operational history are operating as well after the move. The group has also demonstrated reduced 

ambient backgrounds for many of the instruments in the new laboratories. The staff for many of the 

activities within the group are served by single researchers with very little backup. Because of this, the 

Radioactivity Group is at risk of depleting its expertise through an ageing workforce and staff departures. 

EFFECTIVENESS OF DISSEMINATION OF OUTPUTS 

Since 2018, the Dosimetry Group has published 10 manuscripts in peer-reviewed journals and 

proceedings, including two publications with the Radioactivity Group, and selected publications with 

international counterparts. Some staff are active in professional societies, notably the AAPM, but there 

has been limited dissemination of capabilities and results in the scientific community. Expanded 

engagement with professional societies would promote scientific exchanges and enhance state-of-the-art 

practices in areas including, but not limited to, Monte Carlo simulation tools, nuclear data science, and 

detection science. Expanded engagement with university partners, stakeholder programs, and 

international counterparts resulting in joint publication would also be beneficial. Engagement with 

professional societies could help promote participation in the Council on Ionizing Radiation 

Measurements and Standards by students, postdoctoral researchers, and faculty. 
19 

The Neutron Physics Group’s training of postdoctoral researchers and students, both within and 

outside NIST, is highly effective. The group maintains strong collaborations with outside institutions. The 

group has been hosting a large number of graduate students and postdoctoral researchers, academic users, 

and industrial users from the isotope production industry, fuel cell and energy storage industry, national 

laboratories, and the Navy. In recent years, the group hosted summer schools on fundamental neutron 

physics and the 9th Workshop on Neutron Wavelength Dependent Imaging in 2017. The dissemination of 

the group’s program is effective, as evidenced by its 27 publications since 2018. The interferometry team 

has produced 22 publications since 2015. The imaging team, benefitting from a large number of external 

collaborations, has published almost 99 papers since 2015. 

In addition to its basic-science activities, the major way in which the work of the Radioactivity 

Group is disseminated is through the development and availability of standards and standard reference 

materials. From 2009 to 2021, the group completed 30 new standard reference materials and recertified 

22 standard reference materials. The Radioactivity Group participated in international comparisons of 

standards for Cu-64, F-18, Ba-133, Ra-224, tc-99m, and tc-99. From 2017 to 2021, the group published 

37 papers in the peer-reviewed literature. The majority of these papers appeared in the premier journals 

for this type of work. 

GENERAL CONCLUSIONS AND RECOMMENDATIONS

The Dosimetry Group has made major contributions to improved precision of dosimetry metrics 

through Monte Carlo computation improvements, nuclear-data science, and detection science, which in 

aggregate have greatly contributed to the precision of dosimetry measurement. Expanded dissemination 

of this knowledge outside NIST, through greater engagement with university partners, and international 

stakeholders, would accelerate widespread application of this outstanding technology. 

RECOMMENDATION: The Dosimetry Group should expand dissemination of its 

knowledge of radiation metrics through greater engagement with university partners, and 

international stakeholders. 

Staffing of the critical service and research activities within the Dosimetry Group is very top 

heavy, with senior scientists compelled to take on support functions to sustain key activities. It would be 

advantageous to strengthen the student and postdoctoral training functions to help mitigate this problem. 

It would also be useful to give consideration to analyzing and identifying resource allocation priorities in 

a manner that ensures the sustainability of succession planning and knowledge retention, while balancing 

the needs of human capital development and infrastructure improvements. 

The Neutron Physics Group is integral to the Radiation Physics Division through their work on 

neutron calibrations and metrology. Within the group, there is a virtuous cycle connecting the basic 

research with neutrons to the applied research that often benefits from the operationalized products of 

basic research (such as polarized 3

He spin filters) and to the core NIST mission in metrology and 

calibration. Each of these applications benefits from the synergy of technology and staff across the focus 

areas. 

The group’s neutron imaging program provides a set of unique capabilities to multiple 

applications as evidenced by numbers of unique experiments, patents, papers, and RD100 2018 (neutron 

X-ray imaging), awards. Neutron interferometry has transitioned from an artifact of quantum mechanics 

to a versatile tool addressing issues, including nuclear physics and characterization of quantum materials. 

The group is publishing significant papers, many with external collaborators. The beam line used by the 

Neutron Physics Group is the preeminent resource for cold-neutron fundamental physics in the United 

States (based on overall results), and the group is the world leader in the beam measurement of neutron 

lifetime. 
20 

The Neutron Physics Group has made very few new hires over a number of years. The group is 

small for the scope of work for which it is responsible, and this constitutes a risk for a national resource 

essential to maintaining the state of the art in neutron-related measurement and applications. 

RECOMMENDATION: The Radiation Physics Division should examine the ratio of the 

Neutron Physics Groups’ staffing to its workload and consider means of achieving and 

maintaining an effective ratio by increasing staff if appropriate. 

The Radioactivity Group leads the nation in the development of new methods and instruments for 

determining the absolute activity of a radionuclide or mixture of radionuclides. The group is publishing 

and disseminating information on new approaches for determining the absolute activity of a radionuclide. 

The group is fulfilling its mission of advancing measurement science and providing standards for the use 

of radioactive materials in medicine and industry. However, the Radioactivity Group is at risk of 

depleting its expertise due to an ageing workforce and staff departures. 

RECOMMENDATION: The Radiation Physics Davison should address predicted staff 

departures as part of its staffing plan. 
21 

4 

Microsystems and Nanotechnology Division 

The mission of the Microsystems and Nanotechnology Division is to advance nanofabrication 

technologies and use them to develop innovative integrated measurement microsystems. The division is 

organized into the following three groups: the Nanostructure Fabrication and Measurement (NFM) 

Group, Photonics and Optomechanics Group, and Biophysical and Biomedical Measurement (BBM) 

Group. 

TECHNICAL QUALITY OF THE WORK

 The generally impressive work of the Nanostructure Fabrication and Measurement Group is 

broadly focused on improving quality and efficiency in nanofabrication and measurement through 

emphasis on a closed-loop iteration process (virtuous cycles). Group presentations emphasized the 

traceability chain and the ways that a detailed understanding of nanofabrication and measurement impacts 

this chain. For example, the point was made that the transitioning of calibration tools to the field typically 

involves multiple steps, with each step introducing compounding errors. Therefore, nanoscale fabrication 

and measurement provide a direct way of improving commercial calibration tools by greatly reducing the 

uncertainty in the root calibration. Even measurement devices as simple as a tape ruler, which typically 

would be manufactured to have an accuracy less than 1 mm, rely upon root calibration at the nanometer 

scale. Of course, this precision is even more critical in quantum information, such as for the precise and 

accurate placement of quantum emitters within chip-based microcavities and also in medicine, where 

more efficient and higher-accuracy measurements are required in development, testing, and production of 

nanomedicines such as DOXOrubicin. 

The NFM Group is working effectively with the Biophysical and Biomedical Measurement 

Group, and the Photonics and Optomechanics Group. The NFM Group expressed the belief that 

continued improvements made possible by the virtuous cycle will strongly impact nanophotonics in 

particular, where new application areas, such as frequency microcombs, are already demanding nanoscale 

control of macroscale resonant structures for dispersion engineering. This collaborative approach to 

solving problems is commendable. 

The Photonics and Optomechanics Group interacts with other NIST groups and is rapidly 

expanding the range of research to address a wide variety of NIST problems, such as NOAC and 

miniaturized, integrated atomic clocks. The group has achieved a number of recent breakthroughs, such as 

integrated beams in multiple wavelengths for the next generation of Strontium magneto-optical traps for 

atomic optical clocks. The group demonstrated an accelerometer with an order of magnitude better 

sensitivity, based on combining their photonic expertise with their micro-electromechanical systems 

(MEMS) expertise. This is likely to have a significant impact on the inertial-navigation field, and like 

many of its other projects, it will have a large commercial impact. The photonics team is engaged in 

exciting projects, engineering devices at ever-higher frequencies and achieving record high Qs and using 

them for quantum measurements at room temperature. The scientific depth of the group’s scientists, the 

quality and control of the fabrication processes, and the exciting world-record research results that are 

being generated are impressive. 
22 

 The science of biology has critical length scales, from nanometers to meters and beyond. Biology 

is also incredibly complex at every one of these scales. The Biophysical and Biomedical Measurement 

Group is tasked with the formidable challenge of performing triage on critical problems over this range of 

lengths and finding critical technologies and problems to address. One of the great challenges in 

biomedical measurement is moving from the culture dish to the three-dimensional (3D) physiological 

world of tissue, and probing with microelectronic sensors the chemical and physical state of tissue, both 

diseased and healthy. There is a unique effort by the Biophysical and Biomedical Measurement (BBM) 

Group in the Microsystems and Nanotechnology Division, in collaboration with the Advanced Electronics 

Group within the Nanoscale Device Characterization Division, to develop ultra-sensitive nanofabricated 

field-effect transistor pH sensors, which can ultimately be deployed in a clinical setting to probe the 

interior of tissue. 

 In collaboration with the electron-spin paramagnetic sensors being developed within the BBM 

Group, the researchers will begin to develop 3D models of the oxygen, pH, and other critical metabolites 

in tissue. It is very exciting that there is a collaboration developing with AstraZeneca, one of the COVID19 vaccine developers using the technologies being developed here. 

 Micro-nanofluidics plays a central role in biomedical technologies, including biological object 

sorting by size in a range from the nanoscale to the millimeter scale, and in developing fluidic 

connectivity between modular biological units. The team addressing fluidics and cytometry is developing 

new high-throughput, high-precision sorting technologies and measurement technologies to provide 

precise quantitative measurement of the extremely low flow rates often found in these systems. A 

challenge in the field of micro-nanofluidics is the complex and often unknown structure of the objects 

being transported and how they interact with other objects and surfaces. DNA nanotechnology offers an 

ability to design biological structures using well-defined rules that can create both novel materials and 

reproducible complex structures that can be used as transporters in biological systems and as precision 

standards. 

 The team researching microphysiological systems is bringing all of the above technologies 

together in a major effort to put a “body on a chip,” which consists of a number of interconnected 

modules that have tissue cultures of various organs (e.g., liver and bone marrow) to which various drugs 

and physiological stressors (e.g., oxygen, pH, and temperature) may be applied to ascertain in a 

longitudinal manner the way that the various tissue components interact with one another. This is a 

daunting challenge, and it would be beneficial to achieve more integration of the technologies discussed 

above in a 3D manner within this modular assembly of intercommunicating tissues. The impact of this 

technology would be vast, because so many drugs fail with increasing environment complexity. 

TECHNICAL EXPERTISE OF THE STAFF

 The staff of all groups within the division is well organized and well qualified, with impressive 

scientific depth and clear definitions of responsibility and good synergy across groups within the division. 

ADEQUACY OF RESOURCES

 The NFM Group operates in conjunction with the Gaithersburg cleanroom facility, vital to its 

mission that supports focus areas in electron-beam lithography, focused ion beam, scanning electron 

microscopy, atomic force microscopy, super-resolution optical microscopy, and biomolecular assembly. 

Work within NFM and the clean-room facility directly impact the Photonics and Optomechanics Group 

and the BBM Group. It will be important to maintain the cleanroom nanofabrication and characterization 

facilities at a state-of-the-art level. Continued support and investments in this facility will be broadly 

leveraged across technical groups. These facilities will also directly support NIST initiatives such as 

NOAC. 
23 

EFFECTIVENESS OF DISSEMINATION OF OUTPUTS

 The NFM Group is doing an excellent job of disseminating the results of its work through 

publications, direct engagements with industry and universities, distribution of nanofabrication tools such 

as the nanolithography Toolbox, and the development of the JMONSEL simulator tool for precision 

calibration of nanoscale features in scanning electron microscopy. Dissemination of research results on 

the subject of nanoplastics, which is emerging as an environmental challenge with direct consequences 

for human health, will grow in importance. 

 The Photonics and Optomechanics Group’s publication rate in top-tier journals is excellent, and 

the rate of patent filings indicates the novel aspects of their research. The group seems tightly coupled 

with the NFM Group in particular and interacts with other NIST groups. Staff members also have 

collaborations with scientists outside of NIST and seem to be leveraging their skills in other groups to 

secure outside funding and expand the visibility and impact of their research. 

GENERAL CONCLUSIONS 

 The programs within the Microsystems and Nanotechnology Division are of high quality and are 

well aligned with the NIST mission. The researchers are generally superb and frequently among the 

world’s best researchers in the areas of microsystems and nanotechnology, as evidenced by the citation 

data for their publications. The facilities and equipment are top notch, although there are some concerns 

about maintaining expensive processing systems at state-of-the-art levels. The dissemination of outputs is 

reasonable and appropriate, including publication in top-tier journals, cooperative research and 

development agreements (CRADAs) and other relationships with industry, and a steady flow of associates 

into and out of the organization, to and from academia, industry, and national and government 

laboratories. These interchanges occasionally yield permanent appointments at NIST. 

RECOMMENDATION: The Microsystems and Nanotechnology Division should perform a 

forward-thinking analysis to address the concerns about maintaining expensive processing 

systems at state-of-the-art levels. 

 The division chief presented a plot that effectively made the point that the division staff is 

working in a strongly interdisciplinary manner within the division and with many other divisions across 

NIST. This indication that the activities within the division are not siloed—a concern for many technical 

organizations—was borne out by the reviews of the division’s groups. 
24 

5 

Nanoscale Device Characterization Division 

The Nanoscale Device Characterization Division is home to scientists and engineers with deep 

expertise in design, fabrication, and characterization of novel nano- and atom-scale engineering solidstate materials and devices. The vision of the division is to transform nano- and atom-scale technologies 

by advancing measurement science and fundamental knowledge. The division’s mission is to develop and 

advance the measurement and fundamental knowledge needed to characterize nano- and atom-scale 

engineered materials and solid-state devices for innovation in information processing, sensing, and future 

quantum technologies. 

The division is organized into the following five groups: the Advanced Electronics Group, 

Alternative Computing Group, Atom Scale Device Group, Nanoscale Processes and Measurements 

Group, and Nanoscale Spectroscopy Group. The division’s strategic areas of research are as follows: 

theory and measurements for alternative computing; microscopies for quantifying emergent properties in 

quantum materials and devices; advanced microelectronics—integration, characterization, and 

authentication; and atom-scale solid state devices—theory, fabrication, and measurements. 

TECHNICAL QUALITY OF THE WORK 

Overall, the quality of the technical programs is impressive; much of the scientific work at the 

division ranks among the best of the world in its field of research. 

Among the highlights of the division’s technical accomplishments, the extraordinary scanning 

probe effort is a standout. The Alternative Computing Group has developed an impressive platform to 

enable testing of prototype artificial intelligence hardware, available to NIST and its partners. By 

allowing new computing prototypes, such as cross-bar or neuromorphic chips, to be physically integrated 

onto a foundry-fabricated CMOS wafer, to be probed, packaged, and tested as a system, new levels of 

system-level testing have become available. Donor and dot platforms in the quantum area have also made 

great strides and are clearly positioning themselves to make important contributions. 

In a forward-looking research area such as the development of future nanodevices, it can be very 

difficult to assess the needs of industry with respect to NIST’s mission. The division needs an improved 

understanding of which nano- and atom-scale engineered materials and solid-state devices are of greatest 

interest to industry, and what measurements and fundamental knowledge gaps exist with respect to their 

characterization. Division researchers are pursuing promising initiatives whose proposed directions are 

aligned with cutting-edge research and NIST mandates. However, in some instances, there are other 

research groups that are pursuing similar directions and that are ahead or in better institutional positions to 

succeed, by virtue of funding and/or infrastructure. The division’s researchers need to better define their 

current complementary or competitive role, vis a vis external research efforts, and where their research 

needs to be in the future, so that leadership can strategically align resources and laboratory mandates to 

position the researchers for success in these new initiatives. The division needs to develop clearer metrics 

and strategic planning to define and accomplish success and growth goals. It is important to clearly link 

the choice of metrics to the NIST mandates such as advancing U.S. competitiveness, being the laboratory 

for industry, and supporting development of measurement standards. Given the newness of this division 

after a recent reorganization, such gaps in metrics and strategic planning are not unexpected. 
25 

In the area of quantum computing, increased interaction with industry would beneficially inform 

the work being carried out at the division. The phosphorus atomic precision platform could significantly 

help further understanding of control limits (i.e., manufacturing inaccuracy and imprecision) and 

benchmarking of Hamiltonian translation to physical systems. In addition, the unique capabilities in lowtemperature scanning tunneling microscopy (STM) could provide new information on two-level systems 

(TLS) that impact the ever-important issue of T1, qubit energy relaxation time. While there is an extensive 

literature regarding TLS providing a phenomenological framework and conjectures for sources of TLS, 

the atomic-scale sources of energy relaxation have yet to be identified and characterized conclusively 

particularly for next-generation materials of interest. By combining 8 mK temperatures and 7–8 micro 

electron volt energy resolution, using the STM tip to identify defects (e.g., TLS) and then carry out 

spectroscopy on these defects could lead to unprecedented understanding and characterization of TLS. 

The common thread across the division’s work in alternative computing appears to be at the 

device level, as embodied in the non-volatile memory crossbar/platform work. The impending end of 

Moore’s Law seems to imply that today’s emphasis on machine learning based on graphics processing 

units (GPUs) and their huge attendant energy consumption will necessarily end. With this alternative 

computing effort, the division is placing a bet that what will follow GPU- and accelerator-based machine 

learning will be similar to what came before it—biology-inspired neuromorphic, low-energy arrays of 

nonlinear memory elements such as memristors. Crossbar neuromorphic devices utilizing memristors of 

either magnetic tunnel junctions or WO3 (tungsten oxide) are of significant interest in a number of 

companies. The stochastic nature of filament formation and control to vary resistance is actively being 

investigated and is a challenge in issues of control, but importantly an opportunity for ultralow-power 

artificial intelligence computing. 

TECHNICAL EXPERTISE OF THE STAFF 

The caliber and expertise of the senior researchers and associates in the Nanoscale Device 

Characterization Division are impressive. 

ADEQUACY OF RESOURCES 

In general, the facilities of the division are excellent. Much of the equipment is state of the art 

with some pieces being one of a few in the world or one of a kind. The installation of the photoemission 

electron microscopy (PEEM) system and planned inclusion and coupling of a ultraviolet (UV) and deep 

UV femtosecond light source constitutes an exciting addition to the suite of nanoscale analytical tools. 

PEEM can be used to investigate differences in the work functions of individual grains, for example, and 

the inclusion of a femtosecond source could provide information on key dynamics at the nanoscale and 

femtosecond time domain. 

During the review, there was little mention of supercomputing (or even large-scale computing) 

resources available to support the division’s technical work. One theorist said he did not need much 

support, and another researcher said he had adequate access to computing support. Other national 

laboratories, such as Lawrence Berkeley National Laboratory, however, point to their onsite 

supercomputer as being a fundamental required resource for analytics and modeling and argue that 

continuing development of even more capable supercomputers is essential to scientific progress at all 

levels, including basic research. In that context, the division’s apparently modest computing resources 

appear minimal by comparison. One presenter suggested that the COVID-19 pandemic had helped his 

research by making more computing cycles available. “Doing the best with what you have” is a generally 

laudable attitude, and it is in evidence here, but under-resourcing the computing systems available to the 

division’s scientists could effectively limit the scope of their work or delay its completion. If more 

advanced and capable computer systems were to be made available, the division may benefit from adding 
26 

additional skill sets to their current mix. In particular, algorithms experts can be extremely helpful in 

matching what domain experts (the division’s current personnel) know to the tools and methods that best 

suit high-end computing systems. 

During the review, insufficient time was made available for discussion of the adequacy of human 

resources. One apparent inadequacy might be a need to add a person with systems expertise to the team. 

This gap may affect the group’s ability to address issues relating to wear-out mechanisms of non-volatile 

memories. Accessed enough times, any given cell can no longer reliably retain state. Flash memory of the 

kind in USB keys have this characteristic, and the general solution (a systems level approach) is to 

provide a wear-leveling controller that reassigns addresses as needed, to keep any one cell or group of 

cells from being overused. Presentations by division researchers mentioned this problem of wear-out in 

passing, but there was no concerted effort to address it directly. There are both system reliability and 

security implications to this problem that will require higher-than-device-level research to solve. 

EFFECTIVENESS OF DISSEMINATION OF OUTPUTS 

The division is using well the traditional methods of output dissemination, including publications 

in high-quality journals, timely workshops, and direct connections to outside projects. The division is also 

using impressive new channels of communication. For instance, making the atomic force control software 

available on GitHub is a very good first step toward disseminating that work to the widest possible 

audience. A useful follow-up step could be to proactively contact whoever downloads that code to see if 

support or collaboration would be useful. Another example was the crossbar platform for artificial 

intelligence. The design of that system was done with an eye toward facilitating its duplication outside of 

NIST (i.e., using industry standards, appropriate languages, and affordable hardware). This would have 

the intended effect of making future collaboration much more feasible and effective. 

Much of what NIST does is basic research, and fundamental facts about how nature is organized 

are by definition not patentable. However, the innovative work described to the panel showed ample 

examples of material that would clear the novelty threshold required of patents by U.S. law. Unless there 

are legal or policy restrictions at NIST, patenting such work seems worthy of consideration. 

In the area of quantum computing, there is an increasing need for standards development. There 

is a need for standards relating to characterization not only of the qubits but of the elements of the qubits 

such as properties of quantum dots as well as donor and Josephson junction-resonator structures. For 

example, standards and reliable technique development for tunnel barrier characterization, charge noise, 

defect identification, as well as valley splitting (e.g., spatial uniformity) are all areas where groups report 

results from various methods without any authoritative understanding of the comparisons of accuracy and 

precision. Benchmarking of novel computing schemes such as analog quantum simulation is also an 

opportunity, given NISTs present position. Leadership in this area is needed, and perhaps a NIST-led 

workshop series might be timely to help the community to converge in some of these areas. 

GENERAL CONCLUSIONS AND RECOMMENDATIONS 

Because NIST is tasked with developing new characterization technologies, U.S. companies 

would benefit greatly from the capabilities within NIST to develop next-generation tools for addressing a 

range of technical challenges at the nanoscale for companies without the resources to develop these 

analytical probes themselves. 

 RECOMMENDATION: The Nanoscale Device Characterization Division should expand its 

interactions with technology companies within the United States with an eye toward sharing 

information on characterization instrumentation. 
27 

 Adequate computing resources, including supercomputers where appropriate, are essential for 

conducting research at the advanced levels evident at NIST. Such resources may not be currently 

available to the division’s researchers. 

RECOMMENDATION: The Nanoscale Device Characterization Division should conduct 

an analysis to ascertain whether the capabilities of the computing systems available to the 

division’s researchers reflects an effective balance of cost of acquisition, cost of use, and 

utility to the researchers. The division should calibrate the results of such an analysis 

against the capabilities provided to researchers by other national laboratories. 
28 

6 

Sensor Science Division 

The vision of the Sensor Science Division (SSD) is to be the primary driver for innovation in the 

International System of Units (SI)-traceable measurement of dimensional, thermodynamic, and optical 

radiation quantities, enabling the next generation of equitable standards to promote U.S. economic growth 

and security. The mission of the division is to foster the next generation of SI-traceable, dimensional, 

thermodynamic, and optical radiation measurements and their applications by providing calibrations, 

standards, and innovations that improve U.S. industrial competitiveness and quality of life. 

The division is organized into the following seven groups: the Dimensional Metrology Group, 

Fluid Metrology Group, Optical Radiation Group, Remote Sensing Group, Surface and Interface 

Metrology Group, Thermodynamic Metrology Group, and Ultraviolet Radiation Group. The groups work 

collaboratively on nine major topics—measurement services and documentary standards, large-scale 

dimensional metrology, metrology for extreme ultraviolet (EUV) lithography, forensics topography and 

surface metrology, providing SI traceable measurements to support the energy sector, low-background 

infrared radiometry, climate change and greenhouse gas, thermodynamic metrology, and optical 

metrology for solid-state lighting. 

With its institutional responsibility for the realization and dissemination of three of the seven base 

SI units—the meter, the kelvin, and the candela—the SSD is tasked with SI-traceable measurements of 

length, temperature, infrared-to-EUV radiation, pressure and vacuum, surface and interface optical and 

dimensional properties, gas and liquid flow, liquid volume, and humidity. Across SSD’s groups and 

programs, the division is responsible for developing, maintaining, and disseminating national 

measurement standards for these physical quantities; performing measurement comparisons 

internationally to support U.S. competitiveness in the global marketplace; performing research for new 

measurement technologies, methods, and national needs; and providing measurement services, including 

the calibration of practical standards and measurement instruments. The list of stakeholders reliant on and 

requesting NIST impartiality and quality for SI-traceable measurements continues to grow. 

TECHNICAL QUALITY OF THE WORK 

While it is not the role of NIST to specify technical requirements, NIST plays an important role in 

measurement services and documentary standards, advising on measurement techniques and collaborating 

with industry in the development of technical standards. The SSD is engaged in over 25 Standard 

Development Organizations (SDOs) worldwide. Approximately one-third of the staff are actively 

involved in producing documentary standards, and they hold about 58 leadership positions in these 

organizations. Billions of dollars in dimensional metrology equipment are bought and sold using performance specifications from standards developed under SSD leadership and with SSD-developed models 

serving as the technical foundation. This work has resulted in 16 major documentary standards and draft 

documentary standards published since 2017. SSD contributions to dimensional metrology have been 

recognized by the ASTM James A. Thomas President’s Leadership Award and the NIST Edward Bennet 

Rosa Award. NIST staff have also been recognized for their outstanding contributions by awards from the 

International Commission on Illumination, Acoustical Society of America, American Society for 
29 

Mechanical Engineering (ASME), NASA, the American Vacuum Society (AVS), ASTM International, 

and NIST. 

The SSD is currently involved in 19 key comparisons and 16 regional comparisons, which help to 

establish equivalence of measurement standards across national metrology institutes. The published 

results of these key comparisons confirm that NIST staff demonstrably are leaders in many measurement 

disciplines, achieving some of the lowest measurement uncertainties in the world. In terms of impact on 

advanced manufacturing, it is important to note that nearly all large-scale metrology tools are specified 

and tested according to standards developed under SSD staff leadership. 

Stakeholders purchased $2.2 million of products of SSD measurement services (calibration 

services, standard reference materials, laboratory accreditation, and training courses) in fiscal year 2020. 

The measurement services of the SSD account for more than half of the total NIST calibrations 

performed, corresponding to 4,000 artifacts per year. An impressive example of leverage is that four 

NIST-calibrated reference flow meters are used by one manufacturer to calibrate 50,000 mass flow 

controllers. 

SSD staff and leadership expressed a concern that they had lost contact with key customers with 

the implementation of the NIST Storefront, which provides an Internet interface through which NIST 

measurement services are procured. Both end users and staff expressed displeasure in using the current 

Amazon-like interface to procure and deliver services. This may have had several detrimental effects. 

While returning customers provide formal and informal feedback, some traditional customers of NIST 

(major industry segments, Department of Defense [DoD]) have not been able to obtain some needed 

services. Specifically, the long times for some calibrations to be completed, the discontinuation of some 

measurement services, such as the cryogenic liquid flow metrology and the high costs charged to 

customers, are jeopardizing NIST’s position of providing SI traceability for U.S. commerce and national 

security. 

Because NIST typically works with critical, but few-in-number, customers at the top of the 

traceability pyramid, it may be beneficial to contact these customer segments to understand better their 

measurement needs, which have significant impact on the industrial competitiveness and on the U.S. 

security and defense infrastructure. Some NIST calibration services perform well; others could benefit 

from improvement. It would be beneficial for SSD to consider ways to give customers better estimates of 

delivery times for calibration services and provide direct, timely notification when services are not 

available. The SSD might, in collaboration with other NIST divisions, consider having a customer rating 

system on individual services to identify top performers in terms of service metrics and other areas where 

customer service might be improved. This would also likely be useful in quantifying the impact of 

individual measurements performed within SSD, as well as in clarifying the division’s priorities. For 

example, the impact of flow calibration for Brooks was clear. It would be appropriate for the SSD to 

maintain a record of which measurement services have been phased out and why, as well as those added. 

SSD staff reported that some measurement services were not available during renovation of laboratory 

space, and other measurement services have been severely impacted by maintenance issues in aging 

buildings. Renovation of some of the facilities is planned but will take many years to complete. 

The SSD has a worthwhile involvement in the NIST-on-a-chip (NOAC) initiative, which can 

realize the SI directly or disseminate measurements based on properties of nature, whereby the 

traceability chain can be short-circuited to allow standard sensors to exist extramurally. This initiative 

could develop a process that would likely result in significant economic savings for industrial users 

without compromising measurement standards. This effort is extremely forward thinking, and NIST is to 

be commended for putting thought and resources behind an initiative that could potentially obviate some 

of its services and make NIST traceability and error reduction easier. 

A key feature of NOAC is the design, fabrication, and dissemination of embedded, SI-traceable 

sensors that can be incorporated directly into instruments, eliminating NIST as a middleman while 

minimizing sources of uncertainty. Candidate projects for NOAC were identified organically by SSD 

scientists through a standard NIST proposal review system, which takes advantage of significant staff 

enthusiasm and engagement with the NOAC effort. However, there might be missed opportunities for 
30 

identifying other, more important NOAC targets, or places for improved efficiency in identifying targets 

that offer more direct or convenient NOAC integration. The enthusiasm of SSD scientists could be 

channeled into a systematic review of potential targets for NOAC integration to create an overall strategy. 

Such a review could identify new and deserving targets and also identify targets that could reach 

technological maturity faster in order to demonstrate NOAC capabilities and accelerate industry 

acceptance. Thermodynamic metrology capabilities would benefit from such a review, as well as other 

groups that are pursuing NOAC integration. An additional concern with respect to NOAC development is 

the need for a reasonable estimate of the cost of delivering an NOAC to a customer and a clear idea of 

what types and numbers of customers will purchase and use such devices. With its stated goal of creating 

embedded, SI-traceable calibration chips that can be incorporated directly into instruments, it will be 

important for NIST to understand the value proposition for specific customers that NIST expects will 

purchase and embed such chips into their systems. At the end of the review, the panel learned that there 

had been a strategic planning exercise for NOAC but were not given any details of whether any customers 

participated. NIST has developed a roadmap for NOAC, but it was not shared with the panel due to 

confidentiality concerns. As a result, the examples of NOAC within PML seemed unconnected. 

Staff scientists and engineers in SSD have been and continue to be pioneers in large-scale 

dimensional metrology. SSD operates and maintains research and calibration facilities for such 

measurements that are among the best in the world and have been used as models for other industrial and 

national metrology institutes (NMIs). SSD staff invented laser scanning methods that enable precision, 

traceable measurements with on-the-order-of micrometers of uncertainty for length measurements for 

scales involving tens of meters or more. The identification of the previously unknown source of error in 

commercial laser trackers led to creation and dissemination of the NIST geometric model through 

national (ASME B89-4-19) and international (ISO 10360-10) standards. Other outputs of NIST’s research 

have been embedded in ASME standards for tactile coordinate measuring machines (CMMs), articulated 

arm CMMs, laser trackers and scanners, and X-ray-computed tomography. NIST has had good 

collaboration with industry in this area, leading to several CRADAs to build artifacts to test laser 

scanning systems, and the testing procedures associated with them have also been integrated into ASME 

standards. 

The SSD has been a key driver in metrology for the economically important area of EUV 

lithography, an essential tool for semiconductor manufacturing and continuation of Moore’s Law, which 

predicts that the area density of transistors on a chip will double every 2 years. Increasing transistor 

densities that are represented by the transition from the 10 nm node to the 7 nm node, and now to the 5 

nm and 3 nm nodes, require shorter wavelengths of EUV radiation in the lithography tools used to make 

them. The SSD has been involved in key collaborations in the metrology for EUV lithography, including 

optics lifetime, photoresist characterization, and source radiometry due to the capabilities of the 

Synchrotron Ultraviolet Radiation Facility (SURF III). SURF III is an important source of ultraviolet 

(UV) radiation, with its spectral peak output near the wavelength of EUV lithography (13.5 nm). The 

SSD used this capability for industry collaborations in the areas of testing EUV optics lifetimes and 

identifying optics degradation methods; photoresist characterization (e.g., all advanced semiconductor 

materials lithography) witness samples worldwide are traceable to NIST); and source radiometry 

(photodiode calibration), which has aided the industry transition. For example, the Apple APU 

(accelerated processing unit) for the iPhone is made with EUV lithography. The SSD has active CRADAs 

and precompetitive and proprietary work going on with 11 industry players. Industry testimonials attest to 

the importance of NIST and the SURF III to this critical industry transition. Specific SSD research and 

development accomplishments include a model of optic degradation and identification of degradation 

mechanisms for satellites. Upgrades of the SURF III facility have been beneficial for this strategic work. 

NIST is prepared for the transition to 6.7 nm with SURF III, with light output at this wavelength though 

at a lower intensity than at 13.5 nm. The SSD is well connected to this industry and has the opportunity to 

continue to contribute as the industry transitions to 5 nm and 3 nm, while also providing valuable service 

to the scientific customer base.
31 

In the area of forensics topography and surface metrology, the SSD conducts calibrations of 

transfer standards for surface roughness, step height, lateral spacing, and microform geometry for 

manufacturing, forensics, and science. As an example, it provides the world’s lowest measurement 

uncertainty for the microform geometry of standard hardness Rockwell-C diamond indenters used in 

certification of NIST hardness standards. The Forensic Toolmark Analysis Project serves as a case study 

in this area. Firearm and toolmark identification currently relies on subjective evaluation of toolmark 

similarity. SSD facilitated the transition to repeatable 3D topography measurements, developed objective 

similarity metrics, and developed initial statistical models for error rate and weight of evidence 

estimations. It has also created an open-access research database of two-dimensional (2D) and 3D 

toolmark images from a diverse population of firearms and a reference population database of firearm 

toolmarks. This fosters the development of further measurement methods, algorithms, and metrics that are 

likely to offer opportunities for machine-learning methods. The research team is well connected to 

standards organizations and federal, state, and local laboratories, including the Federal Bureau of 

Investigation and the National Institute of Justice, which have supported and/or collaborated on these 

projects. 

Challenges in this area include being able to address industry and manufacturing needs while also 

addressing the toolmark project. Opportunities not met with current resources include optical metrology 

for rougher surfaces, including the important application of optical surface finish metrology for additive 

manufacturing. One of the most significant challenges is the rapid pace of change in firearms that require 

research to address. The ability to address them is limited by staffing resources. The development of the 

national database is time and labor intensive. The team is trying to develop automated systems for the 

Federal Bureau of Investigation, but that also will take additional resources. 

 In the area of providing SI traceable measurements to support the energy sector, the SSD plays a 

vital role in calibrating custody transfer flow meters for natural gas, affecting the sale and use of $300 × 

109

 of natural gas per year. The successful collaboration with CRADA partner CEESI (Colorado 

Engineering Experiment Station, Inc.) has allowed for calibrations with SI traceability to continue. A 

multi-million-dollar project to reduce uncertainty from 0.35 to 0.2 percent is near completion. The SSD 

works with the American Petroleum Institute (API) to provide calibration of the approximately $5 × 1012

per year sale of petroleum products. API documentary standards require recalibration of test measures 

every 5 years, with SSD involvement in the recalibration due to its impartiality, measurement consistency 

and quality protocols, and the SSD’s continuing research to improve liquid volume measurements. Of 

particular note are the use and continuing improvement of automation methods for volume transfer. 

One concern in this area is the loss of the cryogenic liquid flow meter calibration capability for 

liquid natural gas. The facility was shut down and transferred to CEESI, the NIST CRADA partner that 

also performs ambient flow meter calibrations and who agreed to provide calibrations. Due to changing 

circumstances at CEESI, CEESI is no longer performing those calibrations and has shut down the facility. 

VSL, the Netherlands NMI, is the only NMI that does such calibrations. Although SSD staff will be 

working with VSL to establish comparability with NIST measurements when the VSL facility reopens 

later this year, the lack of a U.S. calibration facility for such an important U.S. industry is of concern, 

especially given the industry’s requests to NIST to reinstate the capability. 

The Low-Background Infrared Radiometry program is the primary source of calibrations for a 

key national security customer, the Missile Defense Agency (MDA). The program includes two main 

elements—calibration of cryogenic blackbody sources and transfer radiometers for calibration of user test 

chambers. The SSD’s support of DoD programs has been ongoing for over three decades and is gradually 

evolving because of the requirements for higher sensitivity calibrations. While the direct funding to NIST 

for this program has remained constant for some time, the MDA provides significant staffing for the 

effort at NIST. The SSD effectively engages in research to support these increasing demands. For 

example, there is emphasis on innovation of cryogenic radiometric devices and methods to improve 

sensitivity and speed. The program interfaces with groups at NIST Boulder to employ novel nanotube 

radiometers, thus giving it a pathway to be integrated into the NOAC initiative and eventually allow 

miniaturization and easier traceability. 
32 

The main challenge to the program is the lack of diversity in the customer base, with MDA being 

the principal customer over the entire period of existence of the program. This poses a considerable risk if 

the customer needs change; hence, it would seem advisable to pursue a more vigorous approach to engage 

with other potential customers. The recent collaborations with NASA, the International Thermonuclear 

Experimental Reactor, and the Air Force are laudable and may present a springboard for program 

diversification. 

The Climate Change/Greenhouse Gas program builds upon the mature and successful spectral 

irradiance and radiance responsivity calibration with uniform sources (SIRCUS) capability, which 

enabled pre-flight calibration methods for Earth-observing satellites, was transitioned to NASA, and is 

now used by multiple industrial customers. The satellite calibration service is critical to supporting the 

global effort to understand and mitigate the effects of climate change through improved measurements of 

parameters used in climate modeling. An impressive recent accomplishment is the development of the 

telescope for lunar spectral irradiance calibration, which is suitable for deployment on a high-altitude 

aircraft and was successfully deployed in a demonstration flight campaign. This facility realized a 

considerable reduction of lunar spectral irradiance measurement uncertainty, helping to improve climate 

measurements from satellites. Complementary to space-based observations, the program also developed 

methods to perform greenhouse gas measurements at industrial facilities. Its success in reducing the 

uncertainty and increasing the speed of smokestack flow measurements is admirable and highlights the 

merits of immediate stakeholder engagement, which, in this case, led to a successful field demonstration. 

Of particular note was the use of the NIST smokestack simulator in enabling design of the NIST 

hemispherical 3D airspeed sensor, which reduced errors from 17 to 1 percent. 

Engaging in new programs such as ocean-color measurements, forest productivity, and solarinduced fluorescence highlights the potential for making key contributions in other areas of relevance to 

climate. The growing awareness and investment of resources in addressing the climate change challenge 

globally underscores the need to develop a strategic plan of engagement to prioritize the use of program’s 

resources and enable its growth through staffing and facilities. It appears that such a roadmap currently 

does not exist, and it could be developed in collaboration with other PML, NIST, and other governmental 

and industrial programs. 

Work on pressure measurement is representative of SSD’s strength in the area of thermodynamic 

metrology. The researchers identified an outstanding need in the area of deepest vacuum, where the 

existing pressure gauge technology, in the form of ionization gauges, could not quantify this level of 

vacuum due to the requisite contamination that accompanies this previous state-of-the-art approach. The 

group responded to this need by developing a new methodology, the cold-atom vacuum standard 

(CAVS). More nascent efforts that leverage existing SSD strengths in emissive defects, optical cavities, 

and optomechanics suggest a rich pipeline for further advances in thermodynamics metrology. 

SSD researchers in the area of optical metrology for solid-state lighting provided several 

examples supporting their leadership in this area over the past 15 years. For example, NIST protocols for 

stray-light correction and temperature-compensation of light efficiency have become industry standards 

and, in some cases, have helped lay the groundwork for societal acceptance of new lighting solutions. 

New work on vision science, including color quality of light-emitting diodes, flicker perception, and 

glare, will continue NIST leadership. Newer facilities and products, including a uniquely massive 

integrating sphere, automated photometry bench, new transfer standards, and a setup to show the effects 

of different illumination on human perception, are likely to allow this group to expand their revenue from 

services, which is already in excess of $300,000 per year. Some of these accomplishments were enabled 

by industry partnerships via CRADAs, small business innovative research grants, and patents. One 

demonstration of NIST leadership in this area is best-in-the-world low uncertainty in maintaining the 

candela standard, as demonstrated in 2018. SSD human resources and technical capabilities in this area 

continues to be among the best in the world. 

SSD staff made commendable contributions during the COVID-19 pandemic. From March 2020, 

when staff were required to work remotely, division staff ensured that essential calibrations were 

performed for their customers in support of national security, national well-being, and commerce. 
33 

Directly related to the pandemic, SSD staff conducted special projects on germicidal UV (GUV), 

including measurements of the UV action spectrum for the deactivation of SARS-CoV-2 in collaboration 

with the Department of Homeland Security; development of documentary standards for UV sources, and 

a UV–SIM (Inter-American Metrology System) workshop and UV radiometer distribution; N95 mask 

disinfection using GUV in response to shortages in personnel protective equipment; education on proper 

calibration procedures and use of ambient radiation thermometers through a workshop with 50 

metrologists from 15 countries in the Americas; and standards for vaccine cold storage and transport 

vaccine with the Centers for Disease Control and Prevention (CDC). There has been a 12-year 

collaboration between SSD’s Thermodynamic Metrology Group and the CDC’s Vaccine Supply and 

Assurance Branch on standards and best practices for vaccine cold storage and transport. This effort 

illustrates the broad reach of NIST in ensuring national well-being, beyond national defense and 

economic competitiveness. SSD staff have assisted with the COVID-19 vaccine rollout, addressing 

critical questions related to the transport and monitoring of frozen vaccine. Division staff are likely to 

have continuing roles during this pandemic and in potential future crises. This may have an effect on 

other roles and responsibilities of SSD staff. It is hoped that additional resources can be made available to 

ensure that other high-priority programs are not affected. 

TECHNICAL EXPERTISE OF THE STAFF 

The technical staff for the SSD are internationally respected experts in metrology. The staff holds 

fellowships in the International Society for Optics and Photonics (SPIE), American Physical Society, 

AVS, ASTM, ASME, Acoustical Society of America, and the Illuminating Engineering Society. Division 

staff facilitate global best-metrology practices at an international level through the Bureau International 

des Poids et Mesures (BIPM) consultative technical groups in thermometry, photometry, and radiometry. 

The researchers’ creativity and elite status in measurement science are illustrated by several recent 

awards, a commendable rate of production of papers and patents, and leadership in high-visibility 

initiatives to safeguard national artifacts. These efforts are excellent examples of creativity resulting in 

unique and best-in-world capabilities, and these efforts are likely to result in continued SSD leadership in 

these areas. 

Overall, NIST and SSD support of standards development is impressive. For example, a NIST 

staff member was a co-convener for the revision of International Organization for 

Standardization/International Electrotechnical Commission (ISO/IEC) 17025, the most important 

competency-based standard for calibration and test laboratories. An SSD staff member is a participant in 

the revision of ISO/IEC 17043, general requirements for proficiency testing, which is used as a reference 

for both key comparisons and measurement assurance programs that NIST coordinates. The division leads 

global documentary standards activities for general measurement competency and specific industrial 

sectors, in support of the NIST, PML, and SSD missions. 

ADEQUACY OF RESOURCES 

The aging infrastructure has negatively affected performance of mission-critical activities in the 

form of facilities downtime, burdening technical personnel (because they have to spend time reacting to 

and compensating for deficient environmental conditions and not in performing measurements), and 

systematic degradation of performance metrics. Although examples of issues with NIST infrastructure 

were given throughout the review, some of the most conspicuous were in the Thermodynamic Metrology 

Group. Poorly controlled laboratory humidity keeps experiments using the CAVS tool from being 

routinely conducted, often for months at a time. SSD staff also reported having to do makeshift or 

temporary repairs and solutions to compensate for a lack of long-term environmental upkeep; this 

constitutes weak temporary solutions that ultimately result in more sudden or catastrophic failures. 
34 

Maintenance is funded locally, rather than centrally, and service is generally slow and inadequate. The 

apparent dearth of proper, environmentally stabilized laboratory conditions and proper building 

maintenance are significant impediments to performance of mission-critical activities. Building 

renovations are planned but will take many years at their current pace—a pace that is limited by the NIST 

budget. Building maintenance is slow and inadequate, with the staff performing makeshift repairs that 

often delayed, but did not prevent, catastrophic failure. 

Hiring of additional technician-level staff would significantly streamline calibrations and other 

experiments and would elevate the ability to meet industry’s measurement needs while maximizing the 

efficient time for staff at the ZP-level pay band. Division staff mentioned in several groups and programs 

that productivity would increase if there were additional technicians in the division. This may be a matter 

of having enough available funding or in how headcount is approved—that is, if one new hire per year 

can be added, it may be more likely that it will be a Ph.D., even though two technicians are needed. An 

alternative or complementary strategy could be to provide added support for the continuing development 

of automation capabilities to streamline routine calibrations, where possible. 

Maintaining the high level of expertise over time is a critical concern. SSD staff reported 

continuing challenges in hiring postdoctoral researchers, which are often the entry-level position for Ph.D. 

hires at NIST and in succession planning. With respect to postdoctoral researchers, particularly NRC 

postdoctoral researchers, the issue is the fierce competition for them between base metrology programs 

and other areas of science. The SSD recently was able to bring on two postdoctoral researchers, but that 

seems a low number given the size of the division. The difficulty in succession planning is a continuing, 

serious issue that cannot be addressed without guidance and support from upper management at NIST. 

EFFECTIVENESS OF DISSEMINATION OF OUTPUTS

SSD staff published 240 archival journal papers, technical reports, conference proceedings, and 

book chapters in the past 3 years. Many of those publications appear in prominent scientific journals with 

high impact. Division staff members have presented over 50 invited talks nationally and internationally in 

this period. These metrics attest to the high quality of research and development activity and the division 

culture to widely disseminate the output to the benefit of the public. The division is active in participating 

in or leading interlaboratory measurement comparisons, which generate cooperative agreements with 

industry, government, and universities, as well as interagency agreements. SSD staff participate in over 

25 standards developing organizations and consultative committees that produce documentary standards, 

leading approximately 58 of these committees, with 8 documentary standards and draft documentary 

standards in dimensional metrology published since 2017. Fourteen patents have been issued for 

innovations developed by the division in the recent period. 

Continued engagements in standards organizations, professional society leadership, journal 

editorship, and conference/workshop organization can have a large multiplying effect on dissemination 

and personal career development. Additionally, effective outreach to show the importance of 

measurement science at the K-12 level is an opportunity that could reap long-term benefits to NIST 

staffing and society as a whole. Maintaining and incentivizing these activities is a prudent practice. 

GENERAL CONCLUSIONS AND RECOMMENDATIONS 

The SSD has excellent programs, with an equally excellent staff, aligned with the SSD and NIST 

mission. Its impact on industrial competitiveness, public well-being, and national security is significant. 

The full scope of its activities is broad and diverse. SSD staff hold key leadership roles in national and 

international standards organizations vital to fulfilling the NIST mission. Their efforts to put themselves 

out of some current business and open up new opportunities through the NOAC and through new 

implementations of automation for calibration are commendable. The division has recently started a 
35 

strategic planning exercise with the staff, with the initial outcomes being more open communication and 

trust, which are necessary first steps in setting priorities for a division with such a broad portfolio of 

activities. The SSD staff would benefit from clear metrics for the impacts of the division’s portfolio of 

activities and understanding of division priorities and resource allocation.

RECOMMENDATION: The Sensor Science Division should develop improved metrics for 

the impacts of the division’s portfolio of activities and implement a more formal process for 

establishing division priorities and resource allocation. 

Customers of SSD have expressed dissatisfaction with the timeliness with which measurement 

services are delivered and with the lack of sufficient feedback during the process of performing the 

services. 

RECOMMENDATION: The Sensor Science Division should develop and apply a 

qualitative and quantitative assessment of the quality of customer service for measurements 

and calibrations, using formal and informal feedback on time to completion, quality of 

measurements, and other relevant parameters at an individual service level. 

RECOMMENDATION: The Sensor Science Division should improve communication with 

measurement service customers, providing them estimated times for completion and 

notification if a service is not available. 

RECOMMENDATION: The Sensor Science Division should reexamine the design and 

implementation of the NIST Storefront based on conversations with division staff and 

customers. The division should also perform an assessment of which measurements, 

calibrations, and standard reference materials are no longer available but are still listed on 

the Storefront as being offered. 

Aging infrastructure is a serious issue. It is affecting performance and will ultimately affect 

NIST’s reputation. This is a NIST-wide issue that is noted here to highlight the urgency with which it 

needs to be addressed. 

Having adequate staffing levels continues to be an issue for the SSD with respect to hiring 

postdoctoral researchers and technicians and being able to do meaningful succession planning. These 

require more financial resources and/or a realignment of programmatic priorities. 

RECOMMENDATION: The Sensor Science Division should include in its ongoing strategic 

planning exercise consideration of programmatic priorities in the light of anticipated 

funding sources and available staffing. 
36 

7 

Crosscutting Conclusions 

 This chapter contains conclusions that apply across more than one group or program in the PML 

that was reviewed. 

TECHNICAL QUALITY OF THE WORK

 The accomplishments of PML’s staff are many and significant, spanning an extremely broad 

array of topics and including both research and support of the practical development of measurement 

standards. The staff innovatively develop and apply novel devices and techniques to solve important 

problems that affect industry, academic researchers, federal government agencies, and society in general. 

Their work is effectively aligned with the NIST mission and is frequently performed in collaboration with 

researchers from those organizations. 

 PML staff made commendable contributions during the COVID-19 pandemic. From March 2020, 

when staff were required to work remotely, PML staff ensured that essential services were performed for 

their customers, in support of national security, national well-being, and commerce. PML staff also 

answered the call to address measurement issues relating to combatting the virus, such as disinfecting 

agents and storage of vaccines. 

TECHNICAL EXPERTISE OF THE STAFF 

 All the divisions of the PML have the scientific and engineering staff with the appropriate level of 

expertise to deliver on their mission. In many cases, the staff are the best or among the best in their field 

of research. Staff have received numerous awards from professional organizations and from the 

Department of Commerce, which houses NIST. 

 The gender and minority employment gaps that are still strongly and broadly plaguing STEM 

fields remain an acknowledged significant challenge at NIST as well. The PML has implemented a plan 

to improve equity, diversity, and inclusion that involves the following features: monitoring promotion and 

salary data to ensure an equitable process; publishing promotion criteria so that staff know what is 

expected; mentoring by supervisors on how to advance; reviewing the pay level of all staff members with 

more than 8 years of service; participating in the APS-IDEA in partnership with Howard University; 

sponsoring of and participating in conferences to increase women and minority participation in physics 

and other STEM fields; and supporting the PML Inclusivity Council, an internal grassroots organization 

working to identify barriers to inclusion and propose remedies. Addressing the challenge of staff attrition 

could provide opportunity to address diversity challenges as well. It is expected that in future years PML 

will demonstrate greater efforts and progress in diversity, equity, and inclusion. 
37 

ADEQUACY OF RESOURCES

 Generally, but with significant exceptions, staff are provided with adequate equipment and 

facilities to perform their tasks to a high degree of quality. Noteworthy exceptions include aging facilities 

in urgent need of upgrade, delayed maintenance on aging equipment, and an apparent lack of 

supercomputing support. All divisions reported concern about the adequacy of staffing levels, particularly 

given an aging workforce and severe competition for postdoctoral researchers and other new hires. Each 

division indicated initiation of strategic planning exercises with an eye toward addressing the current and 

predicted challenges associated with the limitations of equipment, facilities, and human resources. 

EFFECTIVENESS OF DISSEMINATION OF OUTPUTS

 PML staff are effectively disseminating the results of their work through appropriate means that 

include publication of research results; delivery of standard reference materials and standard reference 

data; performance of calibrations for industrial, academic, and government customers; participation on 

standards committees; sponsorship of workshops; and educational programs. Some customers, however, 

have complained about the time taken and cost associated with purchased calibration services and about 

the inadequate information provided by the web-based NIST Storefront interface for purchasing 

measurement services, and about the lack of information about which services are currently available. 

39 

Acronyms 

2D two dimensional 

3D three dimensional 

4D four dimensional 

AAPM American Association of Physicists in Medicine 

API American Petroleum Institute 

APS American Physical Society 

ASME American Society for Mechanical Engineering 

ASTM ASTM International, formerly the American Society for Testing and Materials 

AVS American Vacuum Society 

BBM Biophysical and Biomedical Measurement Group 

BIPM Bureau International des Poids et Mesures 

CAVS cold-atom vacuum standard 

CDC Centers for Disease Control and Prevention 

CEESI Colorado Engineering Experiment Station, Inc. 

CMM coordinate measuring machine 

CODATA Committee on Data for Science and Technology 

COVID-19 Coronavirus disease 2019 

CRADA cooperative research and development agreement 

DoD Department of Defense 

DOE Department of Energy 

EPR electron paramagnetic resonance 

EUV extreme ultraviolet 

GPU graphics processing unit 

GUV germicidal ultraviolet 

IDEA Inclusion, Diversity, and Equity Alliance 

JAWS Josephson-junction based arbitrary waveform synthesizer 

JQI Joint Quantum Institute 

LCT Laser Cooling and Trapping Group 

MDA Missile Defense Agency 

NASA National Aeronautics and Space Administration 

NCNR NIST Center for Neutron Research 

nEDM neutron electric dipole moment 
40 

NeXT neutron/X-ray tomography 

NFM Nanostructure Fabrication and Measurement Group 

NIST National Institute of Standards and Technology 

NMI national measurement institute 

NOAC NIST-on-a-chip 

NRC National Research Council (of the National Academies of Sciences, Engineering, and 

Medicine) 

NRCP National Council on Radiation Protection and Measurements 

NSF National Science Foundation 

PEEM photoemission electron microscopy 

PhAND photon-assisted neutron detector 

PI principal investigator 

PML Physical Measurement Laboratory 

PROSPECT Precision Reactor Oscillation and Spectrum experiment 

QED-C Quantum Economic Development Consortium 

QHR Quantum Hall Resistance Standard 

QuICS Joint Center for Quantum Information and Computer Science 

RF radiofrequency 

SI International System of Units 

SIRCUS spectral irradiance and radiance responsivity calibration with uniform sources 

SPIE International Society for Optics and Photonics 

SRI Standard Reference Instrument 

SSD Sensor Science Division 

STEM science, technology, engineering, and mathematics 

STM scanning tunneling microscopy 

SURF III Synchrotron Ultraviolet Radiation Facility 

TLS two-level system 

UV ultraviolet