PML at Work
Highlights of Science and Services
The latest modification of a record-setting strontium atomic clock has achieved precision and stability levels that now mean the clock would neither gain nor lose one second in some 15 billion years—roughly the age of the universe
NIST researchers have determined an important component of uncertainty for near-atomic-scale measurements of the size and shape of miniscule features on chips.
A new milestone has been reached for the PML team developing chip-based thermometers that measure temperature with light. The researchers can now simultaneously connect multiple optical fibers to a chip stably, cheaply, and rapidly.
NIST researchers are investigating a potential mechanism by which firefighters might get steam burns, in which water vapor could quickly penetrate their protective suits and condense on their skin.
The characterization technology needed for nanoelectronic materials and device research, development, and manufacturing was discussed at the 2015 International Conference on Frontiers of Characterization and Metrology for Nanoelectronics (FCMN).
The new approach could meet an important need in the microfluidics industry, which creates devices useful in fields from medical testing to toxin detection.
PML’s Dimensional Metrology Group hosted a three-day training event for 13 industry and government attendees. The class was given in response to an industry-identified need.
A new mathematical proof by PML physicists indicates that quantum processors will work more slowly than some research has suggested.
Scientists at NIST and the National Institutes of Health (NIH) have devised and demonstrated a tiny new shape-shifting probe that is capable of sensitive, high-resolution remote biological sensing not possible with current technology.
A team of researchers has successfully demonstrated a new design concept for a neutron detector that does not rely – as nearly all current models do – on a dwindling worldwide supply of a very rare gas.
NIST scientists and colleagues have created a new kind of sensor that can be used to investigate the telltale isotopic composition of plutonium samples, a critical measurement for nuclear non-proliferation efforts and related forensics.
A new study of traumatic brain injuries using diffusion magnetic resonance imaging (MRI) will get a quality control boost from NIST, which has been working in collaboration with other organizations for nearly a decade to improve quantitative measures for MRI.
Our fast-approaching future of driverless cars and “smart” electrical grids could be stalled by our lack of effective methods to marry computers and networks with timing systems, says a new report released by NIST.
Researchers have developed a new method to reduce uncertainty in X-ray wavelength measurement with implications for the fields of criminal justice, cosmology, and computer manufacturing.
Two PML researchers have been appointed to the Organization of Scientific Area Committees’ (OSAC) Subcommittee on Firearms and Toolmarks, part of an initiative by NIST and the Department of Justice to strengthen forensic science in the United States.
The device developed by Boss for calibrating MRI scanners is designed to standardize imaging of the diffusion of water molecules, a technique that can be useful in diagnosing traumatic brain injury (TBI), neurodegenerative diseases, and cancer.
This state-of-the-art calibration service for will be sensitive enough to detect motion over distances as small as a few nanometers (the size scale of a single molecule) and frequencies up to 50,000 cycles per second (50 kHz).
NIST has now begun offering customers the second generation of its highly successful SSL Measurement Assurance Program (MAP-2), including a new set of lamp artifacts, new detailed measurement protocols, and revised operations.
In response to industrial needs, API and NIST will jointly research and develop new performance tests to help the automotive and aerospace industries understand and improve their industrial measurements.
Doctors devising a plan of attack on a tumor may one day gain another tactical advantage thanks to a series of sophisticated calculations proposed by PML’s Dosimetry group.
Plug-in electric vehicles are prompting increased demand for the electrical equivalent of the corner gas station. Now a standard produced by NIST’s U.S. National Work Group on Electric Vehicle Refueling and Submetering appears to be on its way to adoption.
A little detective work by nuclear physicists has uncovered hidden uncertainties in a popular method for precisely measuring radioactive nuclides, often used to make reference materials for forensic analyses such as radioactive dating.
In an effort to help shoppers everywhere get the best value for their money, researchers at NIST have produced a best practices guide for the layout and design of unit price labels.
A novel Portable Vacuum Standard (PVS) has been added to the roster of NIST’s Standard Reference Instruments (SRI). It is now available for purchase as part of NIST’s ongoing commitment to disseminate measurement standards.
For the first time in half a century, NIST’s 4.45-million newton (equivalent to one million pounds-force) deadweight machine – the largest in the world – is being disassembled for cleaning, restoration, and recalibration. The first stage of the process, dismantling the top half of the three-story stack of weights, is now complete.
A team of NIST scientists has devised and demonstrated a novel nanoscale memory technology for superconducting computing that could hasten the advent of an urgently awaited, low-energy alternative to power-hungry conventional data centers and supercomputers.
Two-dimensional (2D) materials such as molybdenum-disulfide (MoS2) are attracting much attention for future electronic and photonic applications ranging from high-performance computing to flexible and pervasive sensors and optoelectronics. Now PML scientists have discovered a better metal contact that improves two-dimensional transistor performance.
NIST scientists have developed a novel method to rapidly and accurately calibrate gas flow meters, such as those used to measure natural gas flowing in pipelines, by applying a fundamental physical principle.
As cancer diagnostic tools, the new PET-MR imagers have shown promise, but thoroughly assessing their clinical performance requires calibrating the machines in a way that is traceable to a national standard.
NIST has partnered with the private sector to develop the next-generation open-source control software for quantum information systems.
Spotting molecule-sized features—common in computer circuits and nanoscale devices—may become both easier and more accurate with a new sensor developed at NIST.
Two prototypes for tiny chip-based thermometers are illuminating light’s potential to revolutionize the way temperature is gauged.
NASDAQ has announced the launch of a precision time-stamping service for tens of billions of dollars of electronic financial transactions each day based on remote provision of NIST official U.S. time.
NIST imaging with a neutron CT scan was used in a recent investigation by the National Transportation Safety Board.
PML researchers are exploring whether ultrasound can be used to improve quality assurance tests for radiotherapy beams.
PML is helping to bring teachers, students, and manufacturers together to give students access to tabletop scanning electron microscopes.
NIST hosted the Board of Directors of the International Electronics Manufacturing Initiative (iNEMI) this week for an overview of NIST's support of the electronics industry.
PML researchers have applied for a provisional patent on a device to protect expensive “spinning-rotor” high-vacuum gauges – used as transfer standards and reference standards by calibration labs – that are vulnerable to damage during transport.
A joint NIST-DHS project recently completed a series of image quality measurements of a high-energy x-ray vehicle-screening system at a new port-of-entry near El Paso, TX.
An ultra-stable, ultra-thin bonding technology has been adapted by PML researchers for use as a super-strong vacuum seal that is less than 100 nanometers thick.
NIST scientists have devised an experimental photon-detection system for communications with error rates far below even the most ideal conventional designs.
PML has launched a new multi-kilowatt laser power measurement service capability for high-power lasers of the sort used in cutting and welding metals, or defusing unexploded land mines.
Researchers reach a new milestone in the quest to make defect-free nanowires with diameters in the range of 100 nm -- at controlled size and location -- for applications including printable transistors for flexible electronics and high-efficiency light-emitting diodes.
The final frontier of microchip miniaturization is a transistor on the scale of a single atom. PML has iniitated a new research program to create just such a device in manufacturable, solid-state form by harnessing two capabilities unique to NIST.
NASA is funding NIST to use its Traveling SIRCUS laser-based sensor calibration facility to calibrate and characterize the Visible Infrared Imaging Radiometer Suite (VIIRS) sensor on the first satellite in the Joint Polar Satellite System. JPSS will constitute the next generation of polar-orbiting weather satellites, to be developed by NASA and operated by NOAA. The first is expected to launch in early 2017.
Ultra-sensitive magnetic sensor technology pioneered at PML may soon be commercialized for a host of applications from detection of unexploded bombs and underground pipes to geophysical surveying and perhaps even imaging of the brain and heart.
The color of scattered light from sunlit seawater contains important information about ocean health and concentration of substances such as chlorophyll. But taking color measurements from ships has been difficult because of interference from other sources of light -- for example, skylight reflected off the ocean's surface.
Now PML scientists have designed and produced a sand-blasted blue tile to serve as an ocean-like reflectance sample.
The NIST Advanced Radiometer (NISTAR), mothballed for more than a decade, is slated to make its space debut as part of the Deep Space Climate Observatory mission.
At the seventh in a series of workshops, researchers shared state-of-the-art samples for evaluation by about 20 NIST characterization techniques that do not exist anywhere else in the world.
Scientists at the new center will conduct basic research to understand how quantum systems can be effectively used to store, transport, and process information.
PML scientists are improving the standardization of the bullet-stopping chest and back plates worn by US soldiers in battle.
Within weeks of seeing “first light,” a novel pressure-sensing device has surpassed the performance of the best mercury-based techniques in resolution, speed, and range at a fraction of the size. The new instrument, called a fixed-length optical cavity (FLOC), works by detecting subtle changes in the wavelength of light passing through a cavity filled with nitrogen gas.
In a recent demonstration, a pair of laser frequency combs was used to measure the simultaneous signatures of several greenhouse gases along a 2-kilometer path.
The new service is offered for power levels up to 10 kilowatts(kW). These high-power lasers are used by manufacturers for applications such as cutting and welding metals, as well as by the military for more specialized applications like defusing unexploded land mines.
NIST has taken part in a new push to address a persistent and growing problem in physics: the value of G, the Newtonian constant of gravitation. The more experiments researchers conduct to pin G down, the more their results diverge.
Advanced spectrometers pioneered at NIST may speed the arrival of long-awaited materials and devices including advanced high-temperature superconductors and high-efficiency photovoltaic cells.
Image-calibration technology designed and developed by NIST scientists has been adopted for use in multi-site clinical trials in the United States and Europe to study the effects of traumatic brain injury.
James Olthoff, a 27-year veteran of NIST, has been named director of PML.
Researchers at NIST have demonstrated a laser-based imaging system that creates high-definition 3D maps of surfaces from as far away as 10.5 meters. The method may be useful in diverse fields, including precision machining and assembly, as well as in forensics.
To celebrate Metric Week (Oct. 5-11), NIST would like to introduce you to the League of SI Superheroes. The League of SI Superheroes use their incredible powers of measurement to perform amazing feats of science and engineering.
Generating Photons by the Numbers
A new system based on photon pair creation is designed to produce specific numbers of photons on demand, with potentially significant benefits for research, environmental monitoring, astronomy, and other applications.
More and more therapy clinics are using radiation beams with non-standard, complex dose profiles, making it tricky to use traditional calibration tactics. PML scientists demonstrate two potentially better methods that measure subtle changes in temperature using ultrasound or optical light.
Researchers at the University of Waterloo in Canada have directly entangled three photons in the most technologically useful state for the first time, thanks in part to superfast, super-efficient single-photon detectors developed by NIST.
NIST has contributed to the development of a new standard for defining the performance of micromechanical sensors—a field that is expected to expand rapidly in coming decades as these versatile sensors increasingly become part of electronic networks.
Scientists at NIST have determined that polonium-209, the longest-lived isotope of this radioactive heavy element, has a half-life about 25 percent longer than the previously determined value, which had been in use for decades.
SDMD scientists have developed a method that allows the prediction of the current density-voltage curve of a photovoltaic device.
Recent experiments have confirmed that a technique developed several years ago at the National Institute of Standards and Technology (NIST) can enable optical microscopes to measure the three-dimensional (3-D) shape of objects at nanometer-scale resolution—far below the normal resolution limit for optical microscopy.
The discovery, described in Science Express, was made possible by the ultra-stable laser used to measure properties of the world's most precise and stable atomic clock.
Precision calibrations in the extreme ultraviolet range may hasten the advent of a new generation of degradation-free spectrometers for use on satellites that monitor solar radiation.
The newly built research facility, which houses a 50-meter-long horizontal smokestack, will let researchers study the flow characteristics of flue gases and improve the accuracy with which greenhouse gas emissions are monitored.
To make a better optical fiber for transmitting laser beams, the first idea that comes to mind is probably not a nice long hydrogen bath. Researchers at the National Institute of Standards and Technology (NIST) have put this hydrogen “cure” to practical use, making optical fibers that transmit stable, high-power ultraviolet laser light for hundreds of hours.
Physicists at the National Institute of Standards and Technology (NIST) have demonstrated a pas de deux of atomic ions that combines the fine choreography of dance with precise individual control.
Crash-test dummies, yarn-spinning machines and steel girders in bridges. What do they have in common? Look inside them all and you find transducers, devices that measure the forces that push, pull, weigh upon and slam into them. Until recently, it was difficult to calibrate them in all but the simplest sense.
Researchers at the National Institute of Standards and Technology are working to improve ballistics matching methods with assistance from the Prince George's County, Maryland, Police Department Crime Laboratory. Their work together will contribute to a collection of topographic data from thousands of fired bullets and cartridge cases.
NIST researchers have created what may be the most highly enriched silicon currently being produced: more than 99.9999% pure silicon-28 (28Si). Many quantum computing schemes require isotopically pure silicon, for example to act as a substrate in which qubits – the quantum bits that store information – are embedded.
Researchers from the National Institute of Standards and Technology (NIST) and California Institute of Technology (Caltech) have demonstrated a new design for an atomic clock that is based on a chip-scale frequency comb, or a microcomb.
To support the fair sale of gaseous hydrogen as a vehicle fuel, researchers at the National Institute of Standards and Technology (NIST) have developed a prototype field test standard to test the accuracy of hydrogen fuel dispensers.
Two years ago, NIST researchers reported an assessment of the radiation levels produced by a backscatter x-ray system used by TSA to screen airline passengers. Now a National Academy of Sciences (NAS) team is conducting independent measurements of a backscatter machine on NIST’s Gaithersburg campus.
A technology called hyperspectral imaging offers doctors a noninvasive, painless way to discriminate between healthy and diseased tissue and reveal how well damaged tissue is healing over a wide area. The catch? A lack of calibration standards is impeding its use.
Researchers have found a way to change the magnetoresistance of a thin (≈ 100 nm) organic semiconducting material by pairing it with a self-assembled monolayer to alter its characteristics.
Imaging and mapping of electric fields at radio frequencies (RF)* currently requires the use of metallic structures such as dipoles, probes and reference antennas. To make such measurements efficiently, the size of these structures needs to be on the order of the wavelength of the RF fields to be mapped. This poses practical limitations on the smallest features that can be measured.
An exquisitely sensitive, semiconductor-based, single-photon detection system has the highest reported detection efficiency of any device of its type and is capable of detecting hundreds of millions of photons per second with very low noise.
In response to requests from the semiconductor industry, scientists found that atomic force microscope probe tips made from its near-perfect gallium nitride nanowires are superior in many respects to standard silicon or platinum tips.
Scientists have succeeded in measuring a previously unknown but essential property − thermal conductivity −of an ultra-thin material that is expected to play a major role in the fast-emerging field of nanoelectronics.
Relatively little is known about the influence of crowding at the cellular level. A new study shows that it has dramatic effects on individual biomolecules, such as a 35-fold increase in the folding rate of ribonucleic acid.
A chip-scale microfluidic device that both produces and detects a specialized gas used in biomedical analysis and medical imaging has been built and demonstrated.
A suite of precision tests show that excimer scintillation is a highly promising candidate to fill the growing worldwide need for neutron detectors.
A new method may herald a new generation of standards for electrical resistance. It offers substantial performance enhancement over most existing devices.
Jon Pratt, whose group is assembling and testing NIST's new watt balance, explains how the Planck constant is related to mass.
PML Leadership Prominent Throughout Newly Released ITRS
Cable Connections v. Cell Phones
A recently completed suite of measurements found that, in some situations, 4G cell phone signals can interfere with telecommunications connections.
Contributions by NIST to the BICEP2 telescope research project have helped enable discovery of the first direct evidence of cosmic inflation.
The traveling system can be operated at remote sites or in a moving vehicle, and has a volume less than 1 liter. But it produces measurements as accurate at those obtained with laboratory apparatus.
A NIST-CU collaboration through JILA is using ultra-short, high-energy light pulses to study the fundamental physics involved when materials become demagnetized on femtosecond time scales and nanometer spatial scales.
Researchers have developed a powerful new method for 3D characterization of nanostructures using scanning electron microscope data and a library of model shapes.
The researchers used an ultrafast laser and help from German theorists to discover a new semiconductor particle. Although its lifetime is only a fleeting 25 ps, the quantum droplet is stable enough for research on how light interacts with specialized forms of matter.
PML's Office of Weights and Measures was recently asked to convene and lead a meeting of manufacturers, trade groups, and federal officials to reach a consensus on whether certain kinds of aerosol products should be sold by weight or by volume.
Scientists measured the phenomenon -- predicted by theory but never before observed -- in a toroidal population of sodium atoms. Hysteresis is an essential property of electronic systems, and the research could hasten the advent of "atomtronic" circuits for practical devices.
The experimental system at JILA is about 50 percent more precise than the record holder of the past few years, NIST’s quantum logic clock, and would neither gain nor lose one second in about 5 billion years.
NIST partnered with the University of Maryland to sponsor the Mid-Atlantic Conference for Undergraduate Women in Physics from Jan. 17 - 19, 2014. The event drew 135 women from 50 colleges and universities.
Researchers achieved a five-fold reduction in the dominant uncertainty of their measurement methodology. Their results will intensify the worldwide effort to determine the exact lifetime of free neutrons.
A team has developed innovative apparatus to study the way in which standard artifacts gain and lose mass in different environments.
A NIST-JPL collaboration has designed a new detector array that can extract more informaiton than usual from individual particles of light.
Joshua Hadler and colleagues in PML’s Quantum Electronics and Photonics Division have devised a simple, accurate measurement system that can help law enforcement and the judicial system in prosecutions involving a growing threat to aviation: laser attacks.
After two years of examining, refurbishing, and testing the aging workhorse watt balance (NIST-3), PML researchers have used the instrument to obtain their latest measured value of the Planck constant. The next will come from NIST-4, which will begin operations later this year.
The Office of Weights and Measures' Laboratory Metrology program, which recently revised its training and proficiency testing systems, has witnessed the highest test scores in six years.
JILA researchers have developed a method of spinning electric and magnetic fields around trapped molecular ions to measure whether the ions' tiny electrons are truly round.
NIST recognizes outstanding work at the 2013 Awards Ceremony, including achievements by dozens of PML employees.
Researchers have developed prototype calibration tools for a promising experimental medical imaging technique.
Scientists entangle two ions by leaking some information to the environment.
Strengthening the scientific basis of forensic toolmark identification by applying mathematically objective metrics.
The Inner Secrets of Nanowires
New analyses using laser-assisted atom probe tomography show how the composition and morphology of layers depends on conditions during epitaxial growth.
Marilyn E. Jacox, an internationally recognized leader in molecular spectroscopy who joined the National Bureau of Standards in 1962, died on October 30, 2013 at the age of 84.
Using a novel realization of a "phonon laser," scientists at PML and the Joint Quantum Institute have observed and learned to control a process called mode competition.
PML and an international team have joined to engineer and measure a potentially important new class of nanostructured materials for microwave and advanced communications devices.
Physicists have demonstrated a compact atomic clock design that relies on cold rubidium atoms instead of the usual hot atoms -- a switch that promises improved precision and stability.
A team of researchers at PML’s Antenna Metrology Lab in Boulder, CO has devised a first-of-its-kind system combining a precision 3-meter industrial robot arm with a metrology-grade laser tracker and other apparatus – that can measure a probe antenna’s position to within 50 micrometers while it is moving.
During the last week of October, 2013, 53 students from 29 countries attended the metrology school conducted by NIST in Gaithersburg, MD for the Sistema Interamericano de Metrologia (SIM).
Quantum Voltage Standard Delivered to BIPM
A PML team has delivered a state-of-the-art 10 V voltage standard to the International Bureau of Weights and Measures (BIPM), where it will serve as the organization’s newest primary transfer standard for voltage comparisons with national metrology institutes around the world.
Entangling' a Microscopic Drum's Beat with Electrical Signals
Extending evidence of quantum behavior farther into the mesoscopic realm, physicists have demonstrated quantum entanglement between a microscopic mechanical drum and a microwave pulse.
NIST Carbon Nanotube Chips Go Ballooning for Climate Science
A huge plastic balloon floated high in the skies over New Mexico carrying an experimental spectrometer with custom components devised by PML researchers. The instrument will provide data on solar irradiance for climate-related studies.
NIST/JQI Team Gets the Edge on Photon Transport in Silicon
Scientists at PML and JQI have a new way to approach a difficult problem in quantum physics by creating topological edge states of light. The photons behave like electrons in the quantum Hall effect, but respond to a synthetic magnetic field, thus providing a valuable new way to study quantum phenomena.
Force to be Reckoned With: NIST Measures Laser Power with Portable Scale
The new device could become a simpler, faster, less costly and more portable alternative to conventional methods of calibrating high-power lasers used in manufacturing, the military and research. It employs a mirrored scale that detects the force of the incoming laser beam.
The novel structure might be used to simulate or even invent new materials that derive exotic properties from quantum spin behavior, for electronics or other practical applications.
A pair of experimental atomic clocks based on ytterbium atoms has set a new record for stability. The clocks act like 21st-century pendulums or metronomes that could swing back and forth with perfect timing for a period comparable to the age of the universe.
The original Declaration of Independence on display at the National Archives reached its 237th anniversary this year protected by NIST science and engineering.
Three-dimensional (3D) scanners used at crime scenes for forensic investigations are not just the stuff of prime-time television. Investigators and crime laboratories are using laser scanning measurement systems to measure and model, in 3D simulations, the critical aspects of crime scenes.
A new hypothesis concerning a crucial step in the anthrax infection process has been advanced by scientists at NIST and the U.S. Army Medical Research Institute for Infectious Diseases (USAMRIID) at Fort Detrick, Md.
Researchers at JILA have for the first time used an atomic clock as a quantum simulator, mimicking the behavior of a different, more complex quantum system.
The light-emitting diode (LED) appears on track to become the light of our lives. Switching to bright, energy-efficient, durable, and environmentally friendly LED lighting systems could save the nation billions, and PML researchers are helping to make that transition possible.
Many in the electronics industry want to change how memories are made. PML scientists are exploring the physics and developing the metrology required to do just that -- including an evaluative scan technique that is an order of magnitude faster than any comparably accurate method.
A fundamental advance in measurement capabilities that could result in substantial savings for semiconductor manufacturers has earned a 2013 R&D 100 Award for its inventors.
Laser frequency combs, high-precision tools for measuring different colors of light, are becoming essential to fields from medical diagnostics to atomic clocks. Now PML physicists can make the core of a miniature frequency comb in one minute.
A new standard reference material is the first to enable hospitals to link important tissue-density measurements made by CAT scans to international standards.
Researchers at NIST and the Joint Quantum Institute, with colleagues in the Netherlands, have proposed and tested a technique that can initialize a quantum bit that is stored in a semiconductor double quantum dot.