PML at Work
Highlights of Science and Services
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.
Physicists working at NIST and the Joint Quantum Institute are edging ever closer to getting really random. Now they have devised a light source that provides the most efficient delivery of a particularly useful sort of paired photons yet reported.
It's not reruns of "The Jetsons", but researchers working at NIST have developed a new microscopy technique that uses a process similar to how an old tube television produces a picture -- cathodoluminescence -- to image nanoscale features.
A technique developed several years ago at NIST for improving optical microscopes now has been applied to monitoring the next generation of computer chip circuit components, potentially providing the semiconductor industry with a crucial tool for improving chips for the next decade or more.
Fifty years ago on July 5, 1963, a modest radio station in Fort Collings, Colo., offcially went on the airwaves -- a landmark event for U.S. industry and the American public.
PML supports the NIST Nano Environmental, Health, and Safety Initiative with thorough quantitative physical-properties measurements of nanomaterials.
After years of effort and scores of iterations, PML researchers have developed a new generation of devices that can reduce the uncertainties in ac voltage measurements by a factor of three.
MRI Phantoms: Moving to the Next Stage
Closing the Last Bell-Test Loophole for Photons
An international team of researchers has reached a milestone in experimental confirmation of a key tenet of quantum mechanics, using ultra-sensitive photon detectors devised by PML scientists.
Luggage Screening Standards Prove their Value
Until NIST devised one, there was no national standard for evaluating the imaging quality of computed tomography machines used at airports for security scanning of checked luggage -- about 1 million pieces of which are screened every day. Now the new standard is saving substantial time and money.
New NIST Measurement Tool is on Target for the Fast-Growing Mems Industry
As markets for MEMS devices grow and diversify, PML researchers have introduced a long-awaited measurement tool that will help device designers, manufacturers and customers to see eye to eye on eight dimensional and material property measurements that are key to device performance.
NIST Tests in New York City Suggest How to Improve Emergency Radio Communications
Radio communications can be unreliable in underground tunnels and other large, complicated structures, putting first responders at risk. New tests of wireless emergency safety equipment by PML's Kate Remley and colleagues suggest how emergency communications might be improved.
Super-Nanotubes: 'Remarkable' Spray-on Coating Combines Carbon Nanotubes with Ceramic
Researchers from NIST and Kansas State University have demonstrated a spray-on mixture of carbon nanotubes and ceramic that has unprecedented ability to resist damage while absorbing laser light.
NIST Demonstrates Transfer of Ultraprecise Time Signals over a Wireless Optical Channel
By bouncing eye-safe laser pulses off a mirror on a hillside, PML scientists have transferred ultraprecise time signals through open air with unprecedented precision equivalent to the "ticking" of the world's best next-generation atomic clocks.
Don't Call it Vaporware: Scientists Use Cloud of Atoms as Optical Memory Device
Talk about storing data in the cloud: Scientists at NIST, the Joint Quantum Institute, and the University of Maryland have taken this to a whole new level by demonstrating that they can store visual images within quite an ethereal memory device—a thin vapor of rubidium atoms.
New NIST Microcope Measures Nanomagnet Property Vital to 'Spintronics'
PML researchers have developed a new microscope able to view and measure an important but elusive property of the nanoscale magnets used in an advanced, experimental form of digital memory.
NIST Mechanical Micro-Drum Used as Quantum Memory
One of the oldest forms of computer memory is back again--but in a 21st century microscopic device designed by PML physicists for possible use in a quantum computer
Temp-Controlled 'Nanopores' May Allow Detailed Blood Analysis
Tiny biomolecular chambers called nanopores that can be selectively heated may help doctors diagnose disease more effectively.
NIST Quantum Refrigerator Offers Extreme Cooling and Convenience
PML scientists have demonstrated a solid-state refrigerator that uses quantum physics in micro- and nanostructures to cool a much larger object to extremely low temperatures.
New NIST Time Code to Boost Reception for Radio-Controlled Clocks
Researchers in PML's Time and Frequency Division are changing the way NIST broadcasts time signals that synchronize radio-controlled "atomic" clocks and watches to official U.S. time
High Efficiency in the Fastest Single-Photon Detector System
NIST's 'Nanotubes on a Chip' May Simplify Optical Power Measurements
The National Institute of Standards and Technology (NIST) has demonstrated a novel chip-scale instrument made of carbon nanotubes that may simplify absolute measurements of laser power, especially the light signals transmitted by optical fibers in telecommunications networks.
New 3D Defect Detection Fills Important Industry Gap
PML scientists have developed a technique to create a 3D image quickly and non-destructively that can enable fast and non-destructive detection of defects at the nanometer level.
Unprecedented Measurements for Spintronic Components
Calibrating flow meters used on the nation's 300,000 miles of pipelines is a complex, demanding, multi-stage process that begins with apertures 0.2 inches in diameter and ends with 30-inch pipes at 1000 psi.
Sam Benz and colleagues are about to begin delivery of a highly automated, programmable Josephson voltage standard that does not require an expert physicist to operate -- and thus can be used in a wide variety of labs around the globe.
Surprise Findings About Single-Photon Quantum Emitters
Seeing the Oceans in Their True Colors
Analyzing performance and assessing uncertainties in the world's principal instrument for calibration of ocean-color measurements by orbiting satellites is a long, complicated, and evolving job.
PML leads the way in ensuring that SEM users have the ability to gather contamination-free measurements.
MRI: Contrast Agents of Change
Magnetic resonance imaging may soon offer extraordinary new diagnostic and observational possibilities. Recent experiments with magnetic contrast agents hold the promise of real-time imaging of multiple cell types and physiological phenomena simultaneously.
Calibrating a 32,500 pound nuclear waste container to an uncertainty of 0.1 pounds is a highly complicated process that begins with the primary national standard kilogram and works its way up through many orders of magnitude.
Scientists at PML's Quantum Electronics and Photonics Division have devised and improved a novel single-photon detector with 93% system detection efficiency, using an unconventional superconductor for the device's grid of nanowires.
PML’s Semiconductor and Dimensional Metrology Division is finding new ways to support the booming petroleum industry in the area of thread gauge calibrations.
Researchers have demonstrated a novel chip-scale instrument made of carbon nanotubes that may simplify absolute measurements of laser power.
PML's Marlin Kraft was recently asked to troubleshoot DC current measurement problems for a major instrument manufacturer.
Researchers from PML, the NIST Center for Neutron Research, and NIST’s glass/optical shop have devised an innovative, improved spin-polarization filter
Having blood drawn and analyzed to diagnose disease is a process that can take a few days, but what if your doctor could perform this analysis in moments, right before your eyes? That's the promise of "lab on a chip" technology, and researchers are working on a variety of fronts to remove technical roadblocks.
JILA Physicists Achieve Elusive 'Evaporative Cooling' of Molecules
Achieving a goal considered nearly impossible, JILA physicists have chilled a gas of molecules to very low temperatures by adapting the familiar process by which a hot cup of coffee cools.
'Standard Quantum Limit' Smashed, Could Mean Better Fiber-Optic Comms
Communicating with light may soon get a lot easier, hints recent research* from the National Institute of Standards and Technology (NIST) and the University of Maryland's Joint Quantum Institute (JQI), where scientists have potentially found a way to overcome a longstanding barrier to cleaner signals
Bringing Calorimetry to CT Dose Assessment
A team has shown that determining absorbed dose by measuring the temperature change it prompts in plastic phantoms is a valuable complement to the conventional method -- and might eventually come to serve as a primary standard.
A group of researchers from PML's Sensor Science Division is part of a project that will have a direct effect on improved safety of the nation's drinking water.
A new analysis of how PML's online Atomic Spectra Database (ASD) is being used turns up some surprising patterns and preferences. The information will help improve the utility of the reference used worldwide.
Researchers in the Semiconductor and Dimensional Metrology Division's Nanoelectronic Device Metrology (NEDM) Project have demonstrated a phenomenon that could be important in the burgeoning field of spintronics.
Recent experiments suggest that predictions based on the fundamental theory of electromagnetism may not accurately account for the behavior of atoms in exotic, highly charged states.
JILA's new X-Wing addition has received two construction industry awards—best project in higher education/research and special judges' recognition—from the Engineering News-Record, a trade magazine.
Scientists from a PML-Joint Quantum Institute group have devised and demonstrated a novel method for making the most precise measurements to date of the properties of two atomic transitions in rubidium.
Igor Vayshenker of PML's Quantum Electronics and Photonics Division recently completed his 1000th calibration folder for optical power meters.
A team in PML's Quantum Measurement Division is developing a method to grow 99.99 % pure Si-28 crystal to satisfy the needs of the quantum information community at relatively low cost.
NIST might soon be able to provide metrology support for a new generation of photonic temperature sensors with numerous potential benefits over the standard platinum resistance thermometer, including cost and ease of calibration.
The Acoustics Team in PML's Semiconductor and Dimensional Metrology Division have reinstated an agreement with the Department of Veterans Affairs to characterize hearing aids.
Deborah Jin Chosen for 2013 Women in Science Award
Jin, a NIST physicist who works at JILA, will receive the L’Oreal-UNESCO award and $100,000 at a ceremony in Paris next March.
PML tracked, for the first time, the step-by-step motion of a standard type of MEMS device called a "scratch drive actuator."
Collaboration Puts Wheels on the Quantum Bus
In collaboration with Princeton, PML has shown how a major hurdle in transferring information from one quantum bit to another might be overcome.
PML Physicist David Wineland Wins 2012 Nobel Prize in Physics
Wineland, of the Time and Frequency Division, is the fourth PML Nobel laureate in the past 15 years. The composite image at right shows an enlarged photo of an ion trap in the background.
After months of construction, installation, troubleshooting, and testing, the new clean room at NIST's Precision Measurement Laboratory complex on the Boulder campus is now fully operational.
Scientists have created the first controllable atomic circuit that functions analogously to a superconducting quantum interference device and allows operators to select a particular quantum state of the system at will.
A multidisciplinary team has devised and demonstrated a pulsed x-ray source intended to reveal atomic-scale activity with picosecond resolution during chemical reactions.