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Tech Beat - October 22, 2013

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Editor: Michael Baum
Date created: October 22, 2013
Date Modified: October 22, 2013 
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Force to be Reckoned With: NIST Measures Laser Power with Portable Scale

 

Animation of new laser power measurement technique.

Credit: Greg Kuebler and Ian Parker

Researchers at the National Institute of Standards and Technology (NIST) have demonstrated a novel method for measuring laser power by reflecting the light off a mirrored scale, which behaves as a force detector.

Although it may sound odd, the technique is promising as a simpler, faster, less costly and more portable alternative to conventional methods of calibrating high-power lasers used in manufacturing, the military and research.

Optical power has traditionally been measured by comparing it to electrical units. Researchers aim a laser at a coated detector, measure the detector's temperature change, and then determine the electrical power needed to generate an equivalent amount of heat. This method is extremely accurate but difficult with high-power lasers, because it requires slow heating and cooling of massive absorbers. Most absorbers cannot withstand the destructive powers of lasers used for cutting and melting.

Laser power also can be measured by comparison to a reference mass, which is what scales measure, or an equivalent force. This idea is almost as old as the laser but only recently became practical. Large lasers like industrial cutting tools, with output power of 4 to 6 kilowatts, and military lasers with output power of 10 to 100 kilowatts are becoming more common, and they exert enough force to be measured relatively easily. Researchers also now have access to precision scales that can be fitted with mirrors and have the capability to operate either vertically or horizontally. The only limiting dimension is that the mirror needs to be large enough to reflect the laser beam.

NIST's measurement technique, described in a new paper,* measures a laser's force, or the push exerted on a mirror by the streaming photons (light particles). The result, measured in either milligrams (mass) or microNewtons (force), is used to calculate optical power. The scale is first positioned horizontally to be calibrated with a mass placed on top. This "self-calibration" feature means the instrument, if used in the field, would not need to be transported to NIST or somewhere else for periodic evaluations. When used to measure a laser's force, the scale is positioned vertically to be compatible (and safe) with large lasers that typically are mounted horizontally.

Perhaps most intriguingly, light power output can be measured while the laser is being used, thus not wasting any light. The beam is simply reflected off the mirror and directed to a target.

The new measurement method not only simplifies laser power measurements but also advances fundamental measurement science. Now, NIST will be able to compare an optical watt (the basic electrical unit) to a kilogram, the fundamental unit of mass, perhaps leading to improved accuracy in laser power measurements and potentially enabling faster mass calibrations at the microgram level on the factory floor.

NIST researchers have developed and tested a prototype setup with infrared lasers and a commercial scale. The tabletop scale weighs less than 25 pounds. NIST researchers expect the setup would ultimately be about one-fifth the cost of the traditional approach and produce results in about one-tenth the time (less than 2 seconds). The methods are projected to have comparable accuracy of plus or minus 1 percent.

A co-author of the new paper works for Scientech (Boulder, Colo.), which invented the scale used in the experiment.

*P.A. Williams, J.A. Hadler, R. Lee, F. Maring and J.H. Lehman. Use of radiation pressure for measurement of high-power laser emission. Optics Letters. Oct. 15.

Media Contact: Laura Ost, laura.ost@nist.gov, 303-497-4880

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NIST/JQI Team 'Gets the Edge' on Photon Transport in Silicon

Scientists have a new way to edge around a difficult problem in quantum physics, now that a research team from the National Institute of Standards and Technology (NIST) and University of Maryland's Joint Quantum Institute (JQI) have proved* their recent theory about how particles of light flow within a novel device they built.

SEM defect
In this false-color scanning electron microscope image, the arrow shows the path light takes as it hops between silicon rings along the edge of the chip, successfully avoiding defects – in this case a missing ring.
Credit: NIST
View hi-resolution image

While the problem itself—how to find an easier way to study the quantum Hall effect—may be unfamiliar to many, the team's solution could help computer designers use light instead of electricity to carry information in computer circuits, potentially leading to vast improvements in efficiency.

The quantum Hall effect is observed when there is a magnetic field perpendicular to a flat wire that has electrons flowing through it. The field pushes the electrons over to one side of the wire, so their flow is concentrated along its edge. Although a fairly exotic piece of physics, the quantum Hall effect already has been applied to make better standards for electrical conductance. But the effect is hard to study because measuring it requires stringent lab conditions, including extremely low temperatures and samples of exceptional purity.

The team looked for a way around these issues, and in 2011 they found** a potential, albeit theoretical, answer: Build a model system in which particles of light behave exactly like electrons do when subjected to the quantum Hall effect, and study that system instead.

"We knew building an analogous system that uses photons would have additional advantages," says NIST physicist Mohammad Hafezi. "Light can carry much more information than electricity, so working with a photon-based system also could help us design computer components that use light."

To test their theory, the team built an array of tiny, nearly flat silicon rings atop an oxide surface. Beaming photons of the right wavelength at one of the rings makes these photons loop around the ring many times. The rings—which look like 25-micrometer wide racetracks—sit about 150 nanometers from one another, close enough that a photon in one ring can hop to an adjacent one. If a ring happens to be defective—which can and does happen in the fabrication process—the photon instead hops to another ring, but eventually finds its way back to the edge of the array, where it continues traveling. Thus the device transports photons from one place to another even if some of the rings don't function, a key point for manufacturers, who will want devices that work even if they are not physically flawless.

But why go through the trouble of making the photons go ring-hopping? Hafezi says the rings encourage the photons to travel only along the edge of the array instead of taking a path through its midsection—just like electrons experiencing the quantum Hall effect do in a conductor. The secret, he says, lies in the rings' arrangement and its peculiar effect on the photons.

"Our theory showed the topology of the ring array would create the effect we wanted, and our experiment confirms it," Hafezi says. "We now have a robust silicon device that can transport photons at room temperature. We hope it will prove useful for both fundamental studies of physics as well as practical component design."

*M. Hafezi, S. Mittal, J. Fan, A. Migdall and J.M. Taylor. Imaging topological edge states in silicon photonics. Nature Photonics, doi:10.1038/nphoton.2013.274, Oct. 20, 2013.
**See the Aug. 30, 2011, Tech Beat story, "Better 'Photon Loops' May Be Key to Computer and Physics Advances," at http://www.nist.gov/public_affairs/tech-beat/tb20110830.cfm#photon.

Media Contact: Chad Boutin, boutin@nist.gov, 301-975-4261

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NIST Carbon Nanotube Chips Go Ballooning for Climate Science

A huge plastic balloon floated high in the skies over New Mexico on Sept. 29, 2013, carrying instruments to collect climate-related test data with the help of carbon nanotube chips made by the National Institute of Standards and Technology (NIST).

LASP balloon
Scientific balloon launched from New Mexico in September 2013 carrying an experimental instrument designed to collect and measure the energy of light emitted by the Sun, with the help of NIST chips coated with carbon nanotubes.
Credit: LASP
View hi-resolution image

The onboard instrument was an experimental spectrometer designed to collect and measure visible and infrared wavelengths of light ranging from 350 to 2,300 nanometers. Simpler, lighter and less expensive than conventional counterparts, the spectrometer was tested to determine how accurately it can measure the relative energy of light emitted by the Sun and subsequently reflected or scattered by the Earth and Moon.

The flight was launched from the Columbia Scientific Balloon Facility in Fort Sumner, N.M. The balloon travelled with the wind in the stratosphere for about eight-and-a-half hours before radio commands sent the payload parachuting back to Earth. The flight was the first of two intended to demonstrate experimental techniques and acquire sample measurements having possible future applications to Earth climate studies.

Researchers at NIST's Boulder, Colo., campus made the spectrometer's "slit," a high-precision chip that selected the entering light. The device was made under a recent agreement between NIST and the University of Colorado Boulder's Laboratory for Atmospheric and Space Physics (LASP). The slit was then calibrated at NIST's Gaithersburg, Md., headquarters.

For nearly a decade, NIST Boulder researchers have been using carbon nanotubes, the darkest material on Earth, to make coatings for laser power detectors.* Nanotubes efficiently absorb nearly all light across a broad span of wavelengths, a useful feature for reducing internal scatter in the balloon imager. NIST also has facilities for, and expertise in, pairing nanotubes with micromachined silicon chips.**

For the balloon spectrometer, known as HySICS (HyperSpectral Imager for Climate Science), NIST made two types of custom chips that were stacked together in a sandwich. In the middle were aperture chips, coated with aluminum to block light transmission through the silicon, with small rectangular openings etched into the chip to allow light into the instrument.

custom chips
NIST made custom chips coated with carbon nanotubes—the world's darkest material—to absorb scattered light in an experimental balloon-borne spectrometer.
Credit: Tomlin/NIST
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A precision spectrometer must ensure that it only gathers light coming directly from its target, so the two outer layers of the sandwich were masking chips—larger openings etched at an angle and coated with tall, thin carbon nanotubes. These VANTAs ("vertically aligned nanotube arrays") act as superefficient sponges to absorb scattered or stray light across the entire spectral range of the Sun.

While the balloon was in flight, the spectrometer scanned the slit across the Sun to measure solar irradiance. Spectral filters were calibrated by scanning the slit across the Moon and making measurements with and without filters in the beam path. The spectrometer also imaged light emitted from the Earth using the Sun as a reference light source.

NIST's experimental slit was made as part of the LASP Instrument Incubator Project, which fosters the development and evaluation of innovative remote-sensing concepts. LASP scientists will analyze data from the balloon flight in the coming months. For more about the balloon experiment, see http://lasp.colorado.edu/home/blog/2013/10/01/lasp-balloon-launches-with-first-of-its-kind-test-instrument/.

*See the 2010 NIST Tech Beat article, "Extreme Darkness: Carbon Nanotube Forest Covers NIST's Ultra-dark Detector," at www.nist.gov/public_affairs/tech-beat/tb20100817.cfm#dark.
**See the 2013 NIST Tech Beat article, "NIST's 'Nanotubes on a Chip' May Simplify Optical Power Measurements," at www.nist.gov/public_affairs/tech-beat/tb20130124.cfm#radiometer.

Media Contact: Laura Ost, laura.ost@nist.gov, 303-497-4880

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The Reins of Casimir: Engineered Nanostructures Could Offer Way to Control Quantum Effect ... Once a Mystery Is Solved

You might think that a pair of parallel plates hanging motionless in a vacuum just a fraction of a micrometer away from each other would be like strangers passing in the night—so close but destined never to meet. Thanks to quantum mechanics, you would be wrong.

casimir attraction illustration
Researchers measured the Casimir attraction between a metallic grating and a gold coated sphere. They found that the attraction between the nanostructured surface and the sphere decreased much more rapidly than theory predicts when the two surfaces were moved away from each other.
Credit: D. Lopez/Argonne
View hi-resolution image

Scientists working to engineer nanoscale machines know this only too well as they have to grapple with quantum forces and all the weirdness that comes with them. These quantum forces, most notably the Casimir effect, can play havoc if you need to keep closely spaced surfaces from coming together.

Controlling these effects may also be necessary for making small mechanical parts that never stick to each other, for building certain types of quantum computers, and for studying gravity at the microscale.

Now, a large collaborative research group involving scientists from a number of federal labs, including the National Institute of Standards and Technology (NIST), and major universities, has observed that these sticky effects can be increased or lessened by patterning one of the surfaces with nanoscale structures. The discovery, described in Nature Communications,* opens a new path for tuning these effects.

But as often happens with quantum phenomena, the work raises new questions even as it answers others.

One of the insights of quantum mechanics is that no space, not even outer space, is ever truly empty. It's full of energy in the form of quantum fluctuations, including fluctuating electromagnetic fields that seemingly come from nowhere and disappear just as fast.

Some of this energy, however, just isn't able to "fit" in the submicrometer space between a pair of electromechanical contacts. More energy on the outside than on the inside results in a kind of "pressure" called the Casimir force, which can be powerful enough to push the contacts together and stick.

Prevailing theory does a good job describing the Casimir force between featureless, flat surfaces and even between most smoothly curved surfaces. However, according to NIST researcher and co-author of the paper, Vladimir Aksyuk, existing theory fails to predict the interactions they observed in their experiment.

"In our experiment, we measured the Casimir attraction between a gold-coated sphere and flat gold surfaces patterned with rows of periodic, flat-topped ridges, each less than 100 nanometers across, separated by somewhat wider gaps with deep sheer-walled sides," says Aksyuk. "We wanted to see how a nanostructured metallic surface would affect the Casimir interaction, which had never been attempted with a metal surface before. Naturally, we expected that there would be reduced attraction between our grooved surface and the sphere, regardless of the distance between them, because the top of the grooved surface presents less total surface area and less material. However, we knew the Casimir force's dependence on the surface shape is not that simple."

Indeed, what they found was more complicated.

According to Aksyuk, when they increased the separation between the surface of the sphere and the grooved surface, the researchers found that the Casimir attraction decreased much more quickly than expected. When they moved the sphere farther away, the force fell by a factor of two below the theoretically predicted value. When they moved the sphere surface close to the ridge tops, the attraction per unit of ridge top surface area increased.

"Theory can account for the stronger attraction, but not for the too-rapid weakening of the force with increased separation," says Aksyuk. "So this is new territory, and the physics community is going to need to come up with a new model to describe it."

This work was performed in collaboration with scientists from Los Alamos National Laboratory; the University of Maryland, College Park; Argonne National Laboratory; and Indiana University – Purdue University, Indianapolis.

*F. Intravaia, S. Koev, I. Jung, A. Talin, P. Davids, R. Decca, V. Aksyuk, D. Dalvit and D. López. Strong Casimir force reduction through metallic surface nanostructuring. Nature Communications. Published online Sept. 27, 2013.

Media Contact: Mark Esser, mark.esser@nist.gov, 301-975-8735

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NIST Physicists 'Entangle' Microscopic Drum's Beat with Electrical Signals

Extending evidence of quantum behavior farther into the large-scale world of everyday life, physicists at the National Institute of Standards and Technology (NIST) have "entangled"—linked the properties of—a microscopic mechanical drum with electrical signals.

Konrad Lehnert and Tauno Palomaki
NIST physicist and JILA Fellow Konrad Lehnert (left) and post-doctoral researcher Tauno Palomaki in the JILA laboratory where they “entangled” a microscopic mechanical drum with electrical signals. The micro-drum, just 15 micrometers in diameter and 100 nanometers thick, is chilled and manipulated inside the tall tank.
Credit: Baxley/JILA
View hi-resolution image

The results confirm that NIST's micro-drum could be used as a quantum memory in future quantum computers, which would harness the rules of quantum physics to solve important problems that are intractable today. The work also marks the first-ever entanglement of a macroscopic oscillator, expanding the range of practical uses of the drum.

Entanglement is a curious feature of the quantum world once believed to occur only at atomic and smaller scales. In recent years, scientists have been finding it in larger systems. Entanglement has technological uses. For instance, it is essential for quantum computing operations such as correcting errors, and for quantum teleportation of data from one place to another.

The experiments, described Oct. 3, 2013, in Science Express,* were performed at JILA, a joint institute of NIST and the University of Colorado Boulder.

NIST introduced the aluminum micro-drum in 2011 and earlier this year suggested it might be able to store data in quantum computers.** The drum—just 15 micrometers in diameter and 100 nanometers thick—features both mechanical properties (such as vibrations) and quantum properties (such as the ability to store and transfer individual quanta of energy).

The drum is part of an electromechanical circuit that can exchange certain quantum states between the waveform of a microwave pulse and vibration in the drum. In the latest JILA experiment, a microwave signal "cooled" the drum to a very low energy level, just one unit of vibration, in a way analogous to some laser-cooling techniques. Then another signal caused the drum's motion to become entangled with a microwave pulse that emerged spontaneously in the system.

The drum stored the quantum information in the form of vibrational energy for at least 10 microseconds, long enough to be useful in experiments. Then the same type of microwave signal that cooled the drum was used to transfer the state stored in the drum to a second microwave pulse.

Researchers measured the properties of the two microwave pulses—specific points on the curves of the travelling waves—and found that the results were strongly correlated over 10,000 repetitions of the experiment. The evidence of quantum entanglement comes from the fact that measuring the first microwave pulse allowed scientists to anticipate the characteristics of the second pulse with greater accuracy than would otherwise be expected. The correlations between the two pulses indicated that the first pulse was entangled with the drum and the second pulse encoded the drum's quantum state.

The results suggest that the drum, in addition to its potential as a quantum memory device, also could be used to generate entanglement in microwaves, to convert one form of quantum information to an otherwise incompatible form, and to sense tiny forces with improved precision.

The research is supported by the National Science Foundation, the Defense Advanced Research Projects Agency and the Gordon and Betty Moore Foundation.

*T.A. Palomaki, J.D. Teufel, R.W. Simmonds and K.W. Lehnert. Entangling mechanical motion with microwave fields. Science Express. Oct. 3, 2013.
**See 2013 NIST Tech Beat article, "NIST Mechanical Micro-Drum Used as Quantum Memory," at www.nist.gov/pml/div689/drum-031313.cfm.

Media Contact: Laura Ost, laura.ost@nist.gov, 303-497-4880

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Beyond Quantum Simulation: JILA Physicists Create 'Crystal' of Spin-swapping Ultracold Gas Molecules

Physicists at JILA have created a crystal-like arrangement of ultracold gas molecules that can swap quantum "spin" properties with nearby and distant partners. 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.

spin lattice
Illustration of the interaction energies between ultracold potassium-rubidium molecules trapped in a lattice made of intersecting laser beams. The colors indicate each molecule's interaction with the molecule located in the center of the lattice (green), for a specific magnetic-field direction (purple arrow). Blue indicates attractive interactions, and red indicates repulsive interactions. Darker colors indicate higher interaction energy.
Credit: Covey/JILA
View hi-resolution image

Described in a Nature paper* posted online on Sept. 18, 2013, the JILA experiment is the first to record ultracold gas molecules exchanging spins at a distance, a behavior that may be similar to that of intriguing solids such as "frustrated" magnets with competing internal forces, or high-temperature superconductors, which transmit electricity without resistance. The new results build on the same JILA team's prior creation of the first molecular quantum gases and demonstrations of ultracold chemistry.**

JILA is a joint institute of the National Institute of Standards and Technology (NIST) and the University of Colorado Boulder.

"One of the main thrusts for our cold molecules research was to realize this interaction, so this is a major breakthrough," NIST/JILA Fellow Jun Ye says. "We can now explore very exotic new phases of quantum systems." NIST/JILA Fellow Deborah Jin points out that "these interactions are advantageous for creating models of quantum magnetism because they do not require the molecules to move around" the crystal structure.

The new JILA crystal has advantages over other experimental quantum simulators, which typically use atoms. Molecules, made of two or more atoms, have a broader range of properties, and thus, might be used to simulate more complex materials. Jin and Ye are especially interested in using the structure to create new materials not found in nature. An example might be topological insulators—a hot topic in physics—which might transmit data encoded in various spin patterns in future transistors, sensors or quantum computers.

The molecules used in the JILA experiments are made of one potassium atom bonded to one rubidium atom. The molecules are polar, with a positive electric charge at the rubidium end and a negative charge at the potassium end. This feature means the molecules can interact strongly and can be controlled with electric fields.

In the latest experiment, about 20,000 molecules were trapped in an optical lattice, an ordered pattern that looks like a stack of egg cartons created by intersecting laser beams. The lattice was only partly filled, with about one molecule per every 10 lattice wells. The lattice suppressed the molecules' travel and chemical reactions, allowing their internal properties to guide interactions.

The JILA team used microwave pulses to manipulate the molecules' spins, or natural rotations around an axis—similar to a spinning top—to create a "superposition" of two opposite spins at the same time. Scientists then observed oscillating patterns in the average spin of all the molecules, as well as a falloff or decay in the spin signal over time, indicating the molecules were swapping spins.

Scientists calculated the interaction energy that each molecule experiences with all other molecules in the lattice, with the energy intensity depending on the distance and angle between pairs (see graphic). JILA theorist Ana Maria Rey's modeling of spin oscillations and time periods agreed with the experimental measurements. Ye says the spin-swapping interactions "entangle" the molecules, a signature feature of the quantum world that links the properties of physically separated particles.

The results are expected to open up a new field in which scientists create customized molecular spin models in solid-like structures held in place by the lattice. JILA scientists plan to fill the lattice more fully and add an external electric field to increase the variety of spin models that can be created.

The research was funded by NIST, the National Science Foundation, the Air Force Office of Scientific Research, the Army Research Office, the Department of Energy and the Defense Advanced Research Projects Agency.

*B. Yan, S.A. Moses, B. Gadway, J.P. Covey, K.R.A. Hazzard, A.M. Rey, D.S. Jin and J. Ye. Realizing a lattice spin model with polar molecules. Nature. Advance Online Publication, Sept. 18, 2013.
**See 2008 NIST news release, "JILA Scientists Create First Dense Gas of Ultracold 'Polar' Molecules," at www.nist.gov/pml/div689/ultracold_polar_molecules.cfm; and 2010 NIST news release, "Seeing the Quantum in Chemistry" JILA Scientists Control Chemical Reactions of Ultracold Molecules," at www.nist.gov/pml/div689/ultracold_021110.cfm.

Media Contact: Laura Ost, laura.ost@nist.gov, 303-497-4880

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NIST Awards $7.4 Million in Grants for Additive Manufacturing Research

The National Institute of Standards and Technology (NIST) today* announced the award of two grants totaling $7.4 million to fund research projects aimed at improving measurement and standards for the rapidly developing field of additive manufacturing. Benefits of additive manufacturing include producing goods quickly and on-demand, with greater customization and complexity and less material waste.

NIST is awarding $5 million to the National Additive Manufacturing Innovation Institute (NAMII) in Youngstown, Ohio, which is operated by the National Center for Defense Manufacturing and Machining, for a three-phase collaborative research effort involving 27 companies, universities and national laboratories. Northern Illinois University in DeKalb, Ill., will receive $2.4 million to develop tools for process control and qualifying parts made with layer-by-layer additive-manufacturing processes.

“Improving additive manufacturing is an important part of the administration’s efforts to help U.S. manufacturers by supporting new opportunities to innovate,” said Under Secretary of Commerce for Standards and Technology and NIST Director Patrick Gallagher. “The public-private research partnerships led by NAMII and Northern Illinois University are tackling important measurement science-related barriers that must be overcome before this cutting-edge technology can be more widely used, helping America remain innovative and globally competitive.”

Additive manufacturing, also known as 3D printing, is a group of new technologies that build up objects, usually by laying down many thin layers on top of each other. In contrast, traditional machining creates objects by cutting material away. A diverse array of manufacturing industries—from aircraft to medical devices and from electronics to customized consumer goods—are already using or exploring applications of these new technologies.

Additive manufacturing processes face a variety of hurdles that limit their utility for high-value products and applications. Technical challenges include inadequate data on the properties of materials used, limited process control, lack of standardized tests for qualifying machine performance and limited modeling and design tools. The new projects aim to address those challenges.

Specifically, the grants announced today will support NAMII’s three-part research plan that seeks to ensure that quality parts are produced and certified for use in products made by a variety of industries and their supply chains. Northern Illinois University and its collaborators plan to develop a suite of integrated tools for process control and additive manufacturing part qualification. Descriptions of the two projects can be found at http://manufacturing.gov/msam_awards.html.

The competitively awarded grants, which are for two years, were made through NIST’s Measurement Science for Advanced Manufacturing (MSAM) Cooperative Agreement Program.

* Originally issued on Sept. 19, 2013. Minor edits on Oct. 22, 2013, to conform to Tech Beat style.

Media Contact: Mark Bello, mark.bello@nist.gov, 301-975-3776

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NIST Invites Comments on Structure of Forensic Science Guidance Groups

The National Institute of Standards and Technology (NIST) is seeking input on the structure of guidance groups that would promote scientific validity and reliability in forensic science. NIST is inviting comments on the structure of the groups through a Notice of Inquiry published Sept. 27, 2013, in the Federal Register.

The groups, each focused on a specific forensic science discipline, will develop guidance for forensic science practitioners. The proposed mission of the guidance groups, defined in the notice, "is to support the development and propagation of forensic science consensus documentary standards, monitor research and measurement standards gaps in each forensic discipline, and verify that a sufficient scientific basis exists for each discipline."

NIST is responsible for administering and coordinating support for the guidance groups, as outlined in a February 2013 memorandum of understanding* signed by NIST and the Department of Justice (DOJ) to support and strengthen forensic science in the United States. This effort follows a National Academy of Sciences report** detailing the need to strengthen forensic science.

The guidance groups will replace an existing ad hoc system of scientific working groups that are funded by a variety of agencies and have different sizes, structures and output. The groups' impact within their respective fields also varies. NIST seeks to leverage the best work of the existing working groups to standardize activities and output across disciplines.

"We envision the guidance groups as being voluntary collaborative organizations of forensic science practitioners and researchers from a wide array of disciplines. Members would represent all levels of government, academia, non-profits and industry," said Susan Ballou, NIST program manager for forensic science.

Under the memorandum with DOJ, the guidance developed by the NIST-administered groups would be made publicly available so that forensic science practitioners at the state and local levels could adopt it, and it could be considered by the Attorney General for implementation at federal labs.

NIST is considering several possible models for the groups' structure, but all proposed models should have the following attributes:

  • transparency and openness;
  • balance of interests of stakeholders;
  • due process for stakeholder input;
  • consensus process for decision making; and
  • an appeals process.

The Notice of Inquiry asks for comments and responses to questions within four broad areas: structure of the groups, impact of the groups, representation on the groups and the scope of the groups. The comment period will close on Nov. 12, 2013, 11:59 p.m. Eastern Time.

To read the Notice of Inquiry, visit https://federalregister.gov/a/2013-23617. Questions as well as written comments on the guidance groups may be submitted to Susan Ballou, NIST forensic science program manager. Please send questions or comments by email to susan.ballou@nist.gov or to the National Institute of Standards and Technology, c/o Susan Ballou, 100 Bureau Drive, Mailstop 8102, Gaithersburg, MD 20899.

*See the Feb. 15, 2013, NIST news announcement, "Department of Justice and National Institute of Standards and Technology Announce Launch of National Commission on Forensic Science" at www.nist.gov/oles/doj-nist-forensic-science021513.cfm.
**The NAS report is available at www.nap.edu/catalog.php?record_id=12589.

Media Contact: Jennifer Huergo, jennifer.huergo@nist.gov, 301-975-6343

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NIST Unveils Prototype Video Imaging System for Remote Detection of Hidden Threats

Researcher Dan Becker demonstrates NIST's prototype imaging system for remote detection of hidden weapons. The inset on the left is the image created by the instrument, which detects naturally emitted or reflected light at sub-millimeter wavelengths. The ceramic knife is cooler and reflects cooler light from the room, and therefore appears darker than the surrounding image.

By adapting superconducting technology used in advanced telescope cameras, researchers at the National Institute of Standards and Technology (NIST) have built a prototype video imaging system for detecting hidden weapons and other threats at distances up to 28 meters away.

With further development, the new NIST imager might eventually be used for applications such as detecting suicide bomb vests under clothing at military checkpoints or identifying threats at sea such as ships hidden in fog.

NIST’s prototype imager, unveiled at a conference last week,* has three key features, which may offer advantages over other screening systems such as those used for airport security.

First, the NIST imager has NIST-developed software to weave together high-resolution still images to make video in near real time. Second, the system operates from a longer “standoff” distance, 16 to 28 meters away from a target, than other similar imaging systems. These combined features make the NIST instrument unique.

Third, unlike screening systems that bombard a target with X-rays or other types of radiation, the NIST imager is passive, which means it merely detects naturally emitted or reflected light. Similar to an infrared camera, the NIST instrument scans a target to detect emissions of terahertz (also called sub-millimeter) light and then generates images based on variations in temperature and reflected light among different target materials, such as biological tissues versus metals or ceramics.

The long-distance operation is made possible by very sensitive detectors—NIST’s transition-edge sensors. These tiny but sensitive thermometers are made of a superconducting metal, which changes resistance in response to very faint light. The system currently has 251 sensors, and the resulting images show detail as small as 1 centimeter in size across a target area about 80 by 60 centimeters. The system produces less detailed images at the farther end of its operating range.

The technology is similar to that used in NIST's SCUBA-2 telescope camera in Hawaii.** Both instruments detect emissions at a wavelength of 850 micrometers, a wavelength of light that passes through both clothing and the atmosphere. Both sets of sensor arrays are packaged with superconducting amplifiers to boost signal strength, using a NIST technique that makes large arrays practical. But the new imager’s sensors are made of a different metal, aluminum, which superconducts at higher temperatures of 1.2 Kelvin (minus 272 degrees C). This allows the sensor array to be cooled by a more compact, custom refrigerator.

The NIST imager’s video frame rate is currently 6 frames per second, which is relatively slow (standard movie format is 24 frames per second). But NIST researchers say their system can be developed further to have four times as many sensors (for a total of 1,004), which would produce larger, near-full-body images at faster video frame rates.

System components include two mirrors and a lens that focus light on the sensors, a low-temperature refrigerator containing a wafer of sensors and amplifiers, electronics to combine all the signals, and software that stiches the images together into video. All components were designed and built by NIST except part of the refrigerator, built at the University of Pennsylvania, and the electronics, provided by the University of British Columbia.

*D.T. Becker, C.M. Gentry, J. A. Beall, H.-M. Cho, W.D. Duncan, D. Li, G.C. Hilton, K.D. Irwin, N.G. Paulter, Jr., C.D. Reintsema, R.E. Schwall, P.A. Ade, C.E. Tucker, S.R. Dicker, M. Halpern. Passive video imaging at 350 GHz with 251 transition edge sensor bolometers. Talk and video presented at SPIE Remote Sensing Conference, Dresden, Germany, Sept. 24, 2013.
**See 2011 NIST Tech Beat article, “Powerful NIST Detectors on Hawaiian Telescope to Probe Origins of Stars, Planets and Galaxies,” at www.nist.gov/pml/div686/scuba2-array.cfm.

Media Contact: Laura Ost, laura.ost@nist.gov, 303-497-4880

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Grants to Two States Will Support Improved Access to Services and Reduce Fraud

The National Institute of Standards and Technology (NIST) has awarded more than $2 million in grants to the states of Pennsylvania and Michigan to test new online identity technologies to improve access to government services and the delivery of federal assistance programs, and to reduce fraud. The pilot projects support the administration's National Strategy for Trusted Identities in Cyberspace (NSTIC), which envisions an "Identity Ecosystem" that allows people to choose from an array of private and public credentials to prove they are who they say they are online.

"States have a vital role to play in the Identity Ecosystem, both providing identity credentials and relying on them," said NSTIC's Jeremy Grant, senior executive advisor for identity management. "States are ideal partners for NSTIC pilots because of the many services they offer online, and the many more they could offer online if the costs and risks involving identity fraud could be reduced."

These new state pilots complement five NSTIC grants recently awarded to private-sector organizations.  Additional funding for the state pilots is provided by the Partnership Fund for Program Integrity Innovation, which was established by Congress in 2010 to help federal agencies and state governments work together to find smarter ways to meet the demands of citizens and act as responsible stewards of taxpayer resources. Administered by the Office of Management and Budget in consultation with the Collaborative Forum of states and other stakeholders, the Partnership Fund enables federal, state, local, and tribal agencies to pilot innovative ideas for improving assistance programs in a controlled environment.

Both state pilot programs focus on giving their citizens improved methods for accessing a variety of government services.

With a $1.3 million NSTIC grant, the Michigan Department of Human Services will pilot the use of secure, privacy-enhancing online identity verification and authentication solutions with Bridges, Michigan's integrated eligibility system that supports online enrollment and registration for citizens seeking public assistance. The program will aim to help eliminate barriers citizens face in accessing benefits and services by streamlining the applications process, while also reducing fraud and improper payments. Today in Michigan, all applicants for public assistance and other services must appear in person to have their identity verified—an expensive process for the state and a burdensome one for citizens—which often results in delays to benefits. The pilot project will also evaluate how residents can more securely access their private information using multi-factor authentication solutions in lieu of passwords.

With a $1.1 million NSTIC grant, the Commonwealth of Pennsylvania pilot will offer residents the opportunity to obtain a secure, privacy-enhancing credential to conduct online transactions with a number of participating agencies including the departments of Public Welfare and Health. Citizens will be able to register just once to access a variety of services, eliminating the need to create multiple accounts and to validate their identity multiple times. If successful, these higher security accounts will allow new types of online transactions, increasing convenience while also helping the state reduce fraud.

NIST is also awarding $300,000 to the Research Triangle Institute to evaluate the benefits and impacts of identity solutions deployed in the Michigan and Pennsylvania pilots. By advancing the knowledge gained from the pilot projects and disseminating it broadly to policymakers, state agencies, and the public, the evaluation will assist in moving forward the objectives of both NSTIC and the Partnership Fund.

Media Contact: Jennifer Huergo, jennifer.huergo@nist.gov, 301-975-6343

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NIST MEP Sets Up One-Stop Shop for Manufacturing-Related Research and Reports

The Hollings Manufacturing Extension Partnership at the National Institute of Standards and Technology (NIST MEP) has a new website where users can find a collection of reports and studies on manufacturing policy and practice.

The site is intended to serve as a resource for the manufacturing community and to fuel vibrant discussion and debate about the future of manufacturing in the United States. The posting of these works does not necessarily imply that NIST MEP endorses the views they express.

“Manufacturing has been, is, and will be essential to our nation's competitiveness, in part because the sector drives and adapts to change in technology, trade and the workforce,” said NIST MEP’s Gary Yakimov. “A lot of organizations are putting out research relevant to manufacturers. We wanted to make it easy for the community to find by gathering it all in one place.”

The new website offers reports and research organized by topic area, including:

  • Current State of Manufacturing
  • Innovation, R&D, and IP
  • Capital & Cost
  • Global Competitiveness
  • Federal/Industrial Collaboration
  • Education & Workforce
  • Regulatory & Policy Recommendations
  • Best Practices
  • Productivity
  • Sustainability
  • Supply Chain

According to Yakimov, although the site is not comprehensive, suggestions for worthy reports that may have been overlooked may be sent as a link or an attachment along with a brief description to gyakimov@nist.gov. If the suggested work is appropriate, NIST MEP will include it on the website at www.nist.gov/mep/mepreports.cfm.

Media Contact: Jennifer Huergo, jennifer.huergo@nist.gov, 301-975-6343

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NIST-University of Maryland Conference to Highlight Women in Physics

The National Institute of Standards and Technology is partnering with the University of Maryland to co-host the 2014 Conference for Undergraduate Women in Physics (CUWiP) conference from Jan. 17 -24, 2014. The goal of the event is to encourage undergraduate women to continue in physics by providing them with the opportunity to experience a professional conference, acquire information about graduate school and professions in physics, and interact with other women in physics of all ages with whom they can share experiences, advice and ideas. For NIST, these women represent a key piece of the puzzle in recruiting the best and brightest for public service.

The first day of the conference will feature six hours of talks and tours at NIST's Gaithersburg, Md., facilities. Nobel Laureates and physicists from NIST's Physical Measurement Laboratory will be active in numerous aspects of the CUWiP program throughout the weekend.

The NIST-UMD site and program was competitively selected as one of only eight such events nationwide, conducted under the auspices of the American Physical Society (see www.aps.org/programs/women/workshops/cuwip.cfm.)

For more information on the NIST-UMD conference, visit www.physics.umd.edu/cuwip/. For information on how to apply, visit www.aps.org/programs/women/workshops/cuwipapp.cfm. The application deadline is Nov. 1, 2013.

Media Contact: Michael Baum, michael.baum@nist.gov, 301-975-2763

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CU-Boulder and NIST Joint Institute Physicist Ana Maria Rey Wins 2013 MacArthur Fellowship

Additional Contact:
Malinda Miller-Huey, CU spokesperson, 303-492-3115

Ana Maria Rey, a theoretical physicist and a fellow of JILA, a joint institute of the National Institute of Standards and Technology (NIST) and the University of Colorado Boulder, today was named a winner of a 2013 MacArthur Fellowship, commonly known as a "genius grant."

Ana Maria Rey
Physicist Ana Maria Rey, a fellow of JILA, has been named a winner of a 2013 MacArthur Fellowship.
Credit: Courtesy of the John D. amd Catherine T. MacArthur Foundation
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Rey, 36, was one of 24 recipients of the 2013 "no-strings attached" funding, and she will receive $625,000, paid out over five years. An assistant research professor in the CU-Boulder Department of Physics, Rey is the eighth CU-Boulder faculty member to win the prestigious award from the John D. and Catherine T. MacArthur Foundation of Chicago as well as the fourth physics faculty member and third JILA fellow to win.

"It is a great honor for me to be a MacArthur fellow and to receive such great recognition of my work," Rey said. "I want to thank JILA, NIST, CU-Boulder and the outstanding group of colleagues, collaborators and students who have allowed and helped me to accomplish the research I have done."

The MacArthur Foundation selection committee cited Rey as an "atomic physicist advancing our ability to simulate, manipulate, and control novel states of matter through fundamental conceptual research on ultracold atoms." 

"We congratulate Professor Rey on this exciting award, and we also congratulate our faculty, whose ranks now include five Nobel laureates and eight MacArthur Fellowship winners," said CU-Boulder Chancellor Philip P. DiStefano. "I believe Professor Rey's work is emblematic of the research, innovation and discovery at CU-Boulder, a body of work and a collection of great minds that is unmatched anywhere in the Rocky Mountain region and few places around the nation."

Tom O'Brian, chief of the NIST Quantum Physics Division and Rey's supervisor, said, "Ana Maria has rapidly established herself as one of the world's top young theoretical physicists. She has a special ability to make very practical applications of theory to key experiments. Ana Maria has been crucial to the success of such world-leading NIST/JILA programs as ultracold molecules, dramatic improvements in optical lattice clocks, and use of cold atom systems and trapped ion systems for quantum simulations."

At JILA, Rey works with ultracold atoms and molecules that are trapped in an "optical lattice," a series of shallow wells constructed of laser light. Atoms that are loaded into an optical lattice behave similarly to electrons in a solid crystal structure. But while it's difficult to change the properties of a solid crystal, the properties of an optical lattice—which essentially acts as a "light crystal"—are highly controllable, allowing Rey to explore a whole range of phenomena that would be nearly impossible to study in a solid crystal system.

Ultimately, Rey hopes her research will lead to the ability to engineer materials with unique characteristics such as superfluids—liquids that appear to move without regard for gravity or surface tension—and quantum magnets—individual atoms that act like tiny bar magnets.

Before coming to JILA in 2008, Rey was a postdoctoral fellow at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., and a postdoctoral researcher at NIST in Gaithersburg, Md. 

Rey began studying physics at the Universidad de los Andes in Bogota, Colombia, where she received a Bachelor of Science degree in 1999. She came to the United States to continue her studies, earning a doctorate in physics from the University of Maryland, College Park, in 2004.

Previous CU-Boulder faculty members who have won a MacArthur Fellowship include David Hawkins of philosophy in 1981; Charles Archambeau of physics in 1988; Patricia Limerick of history in 1995; Margaret Murnane of physics and JILA in 2000; Norman Pace of molecular, cellular and developmental biology in 2001; Daniel Jurafsky of linguistics and the Institute of Cognitive Science in 2002; and Deborah Jin of JILA, NIST and physics in 2003.

"Everyone at JILA is extremely proud of Ana Maria Rey's accomplishments and wholeheartedly congratulate her for this prestigious MacArthur Fellowship," said JILA Chair Murray Holland. "She has an incredibly quick mind for physics and is one of the truly creative and ingenious scientists of her time, while also being a wonderful teacher and mentor to both undergraduate and graduate students. This is a great honor for Ana Maria, and a tremendous recognition of the important research programs in JILA and NIST."

Rey is a highly effective mentor for an unusually large group of graduate students and postdoctoral fellows given the early stage of her career, O'Brian said. One of her recent graduate students, Michael Foss-Feig, won the prestigious 2013 Best Thesis Award of the American Physical Society's Division of Atomic, Molecular and Optical Physics. Rey won the same award in 2005 as a graduate student at the University of Maryland.

On Sept. 24, 2013, in another honor, the American Physical Society named Rey the winner of the 2014 Maria Goeppert Mayer Award, which recognizes outstanding achievements by a woman physicist in her early career.

Additional information on Rey is available at http://www.macfound.org/fellows/901 and http://jila-amo.colorado.edu/science/profiles/ana-maria-rey. To learn more about JILA, visit http://jila.colorado.edu/.

As a non-regulatory agency of the U.S. Department of Commerce, NIST promotes U.S. innovation and industrial competitiveness by advancing measurement science, standards and technology in ways that enhance economic security and improve our quality of life. To learn more about NIST, visit www.nist.gov.

Note to Editors: To request interviews with Ana Maria Rey contact Peter Caughey at 303-492-4007 or caughey@colorado.edu. Rey also can conduct interviews in Spanish. Photos are available for downloading from the MacArthur site link.

Media Contact: Laura Ost, laura.ost@nist.gov, 303-497-4880

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NIST Fire Protection Engineer Wins Service to America Medal

Fire protection engineer Daniel Madrzykowski of the National Institute of Standards and Technology (NIST) was honored on Oct. 3, 2013, with a Service to America Medal* for research and outreach efforts that have “dramatically improved firefighting practices,” saving firefighters’ lives and protecting property across the nation.

Portrait of Dan Madrzykowski
NIST fire protection engineer Daniel Madrzykowski is a winner of the 2013 Service to America Medal.
Credit: NIST 
High resolution version

A 28-year NIST veteran, Madrzykowski is credited with advancing tactics for fighting fires ranging from high-rise blazes to house fires. Much of his research is conducted through fire experiments—or controlled burns—that he carries out with local fire departments in buildings that are planned for demolition.

“Dan epitomizes the NIST mission to do science that advances the public interest,” said NIST Director Patrick Gallagher, who also is acting deputy secretary of the Department of Commerce. “He’s conducted top-notch fire-dynamics research that saves lives and dollars, and he’s not content with just publishing the results. He spreads the word by teaching numerous courses, distributing tens of thousands of copies of educational videos, operating a popular website for the fire-service community and serving on many standards committees.”

The Partnership for Public Service recognized Madrzykowski in the award’s citizen services category. The award honors federal employees for significant contributions to the nation in activities related to citizen services, such as education, health care, economic development and community protective services.

Service to America Award Winners 2013
President Barack Obama meets with Samuel J. Heyman Service to America Medals finalists and winners in the East Room of the White House, Oct. 23, 2013. (Official White House Photo by Pete Souza)
Photo Restrictions: This official White House photograph is being made available only for publication by news organizations and/or for personal use printing by the subject(s) of the photograph. The photograph may not be manipulated in any way and may not be used in commercial or political materials, advertisements, emails, products, promotions that in any way suggests approval or endorsement of the President, the First Family, or the White House.

Madrzykowski is a pioneer in the relatively young field of fire dynamics in structures. Through controlled-burn experiments, he and his collaborators have challenged conventional fire-fighting wisdom, like banging open the front door or breaking windows upon arriving at a house fire. He has shown how the flow of air in a burning structure can dramatically influence how a fire grows in intensity and spreads.

These experiments have led to new science-driven firefighting methods for strategically ventilating and isolating fires that can prevent—or at least delay—flashover. This extremely hazardous phenomenon occurs when heat builds up in a burning structure’s contents to the point that they burst into flames simultaneously.

At NIST, Madrzykowski has become a role model and mentor for translating research findings into actual changes in stakeholder communities. “His work demonstrates the value of collaborating with organizations outside of NIST to move information and ideas forward and into practice,” Gallagher says.

A fellow of the Society of Fire Protection Engineers, Madrzykowski has won numerous awards. In 2009, he was named instructor of the year by the International Society of Fire Service Instructors. The Fire Department of New York City inducted him as an honorary battalion chief in 2012. For more information about NIST fire fighting research, go to www.nist.gov/fire.

*Read the Service to America citation for Madrzykowski at http://servicetoamericamedals.org/SAM/recipients/profiles/csm13_madrzykowski.shtml.

Media Contact: Mark Bello, mark.bello@nist.gov, 301-975-3776

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Allan Harvey Elected ASME Fellow

Allan Harvey, a chemical engineer in the National Institute of Standards and Technology (NIST) Material Measurement Laboratory, has been elected as a fellow of the American Society of Mechanical Engineers (ASME).

ASME fellows are an elite group, representing less than 3 percent of the 100,000+ ASME members worldwide. Harvey is being recognized for his long-term, dedicated, and expert service to the ASME Research Committee on Water and Steam in Thermal Systems, especially its subcommittee on the Properties of Water and Steam. Harvey is an expert in chemical thermodynamics, molecular science, and frontier areas of computing and molecular simulation.

His research has deepened our understanding of near- and supercritical solutions, leading to predictive estimations of properties for practical applications. He has also initiated international collaborations on ab-initio calculations of nonideality of vapors when needed data are scarce or inaccurate. Harvey has played a central role in disseminating standard reference data for thermophysical properties of water and steam, data which are critical for researchers and engineers in the electric power industry, the chemical process industry and geosciences.

Media Contact: Michael Baum, michael.baum@nist.gov, 301-975-2763

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