NIST Tech Beat - March 16, 2006

A study by the National Institute of Standards and Technology (NIST) shows that computerized systems that match fingerprints using interoperable minutiae templates—mathematical representations of a fingerprint image—can be highly accurate as an alternative to the full fingerprint image. NIST conducted the study, called the Minutiae Interoperability Exchange Test (MINEX), to determine whether fingerprint system vendors could successfully use a recently approved standard* for minutiae data rather than images of actual prints as the medium for exchanging data between different fingerprint matching systems.

Minutiae templates are a fraction of the size of fingerprint images, require less storage memory and can be transmitted electronically faster than images. However, the techniques used by vendors to convert fingerprint images to minutiae are generally proprietary and their systems do not work with each other.

For many years, law enforcement agencies have used automated fingerprint matching devices. Increasingly, smart cards—which include biometric information such as fingerprints—are being used to improve security at borders and at federal facilities. The increased use and the desire to limit storage space needed on these cards is driving the use of minutiae rather than full images.

Fourteen fingerprint vendors from around the world participated in MINEX. Performance depended largely on how many fingerprints from an individual were being matched. Systems using two index fingers were accurate more than 98 percent of the time. For single-index finger matching, the systems produced more accurate results with images than with standard minutia templates. However, systems using images and two fingers had the highest rates of accuracy, 99.8 percent. Results of the test are available at http://fingerprint.nist.gov/minex04/.

MINEX was sponsored by the U.S. Departments of Homeland Security and Justice. The test was not conducted to recommend or endorse any products or equipment.

Physicists at JILA have designed and demonstrated a highly sensitive new tool for real-time analysis of the quantity, structure and dynamics of a variety of atoms and molecules simultaneously, even in minuscule gas samples. The technology could provide unprecedented capabilities in many settings, such as chemistry laboratories, environmental monitoring stations, security sites screening for explosives or biochemical weapons, and medical offices where a patient’s breath is analyzed to monitor disease.

Described in the March 17 issue of Science,* the new technology is an adaptation of a conventional technique, cavity ring-down spectroscopy, for identifying chemicals based on their interactions with light. The JILA system uses an ultrafast laser-based “optical frequency comb” as both the light source and as a ruler for precisely measuring the many different colors of light after the interactions. The technology offers a novel combination of a broad range of frequencies (or bandwidth), high sensitivity, precision and speed. A provisional patent application has been filed.

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

“What a frequency comb can do beautifully is offer a powerful combination of broad spectral range and fine resolution,” says NIST Fellow Jun Ye, who led the work described in the paper. “The amount of information gathered with this approach was previously unimaginable. It’s like being able to see every single tree of an entire forest. This is something that could have tremendous industrial and commercial value.”

Frequency combs are an emerging technology designed and used at JILA, NIST and other laboratories for frequency metrology and optical atomic clocks, and are being demonstrated in additional applications. NIST/JILA physicist John (Jan) Hall shared the 2005 Nobel Prize in physics in part for his contributions to the development of frequency combs [www.nist.gov/public_affairs/newsfromnist_frequency_combs.htm]. In the application described in Science, the frequency comb is used to precisely measure and identify the light absorption signatures of many different atoms and molecules.

* M.J. Thorpe, K.D. Moll, R.J. Jones, B. Safdi and J. Ye. 2006. Broadband cavity ringdown spectroscopy for sensitive and rapid molecular detection. Science. March 17.

Record-breaking Detector May Aid Nuclear Inspections

Silicon chip built by NIST researchers with 16 tiny gamma ray detectors that may help nuclear inspectors improve analysis of plutonium and other radioactive materials. Each detector is one millimeter square.

View a high resolution version of this image.

Image credit: NIST

Scientists at the National Institute of Standards and Technology (NIST) have designed and demonstrated the world’s most accurate gamma ray detector, which eventually is expected to be useful in verifying inventories of nuclear materials and detecting radioactive contamination in the environment.

The tiny prototype detector, described March 14 at the American Physical Society national meeting in Baltimore, can pinpoint gamma ray emission signatures of specific atoms with 10 times the precision of the best conventional sensors used to examine stockpiles of nuclear materials. The NIST tests, performed with different forms of plutonium at Los Alamos National Laboratory,* also show the prototype greatly clarifies the complex X-ray and gamma-ray emissions profile of plutonium.

Emissions from radioactive materials such as uranium or plutonium provide unique signatures that, if accurately measured, can indicate the age and enrichment of the material and sometimes its intended purpose or origin.

The 1-square-millimeter (mm) prototype collects only a small amount of radiation, but NIST and Los Alamos researchers are collaborating to make a 100-sensor array that could be deployed in the field, perhaps mounted on a cart or in a vehicle.

“The system isn't planned as a primary detection tool,” says NIST physicist Joel Ullom. “Rather, it is intended for detailed analysis of material flagged by other detectors that have larger collection areas but less measurement accuracy.” An array could be used by inspectors to determine, for example, whether plutonium is of a dangerous variety, whether nuclear fuel was made for energy reactors or weapons, or whether what appears to be radium found naturally in the environment is actually explosive uranium.

data plot of gamma rays with specific energies

The data plots above show detection of gamma rays with specific energies. Arrows point to energies identified with the new detector that are difficult to detect in the red plot made with a conventional detector.

View a high resolution version of this image.

Image credit: NIST, National Nuclear Security Agency, Los Alamos National Laboratory

For further information, see www.nist.gov/public_affairs/releases/
gammaraydetector.htm.

* J.N. Ullom, B.L. Zink, J.A. Beall, W.B. Doriese, W.D. Duncan, L. Ferreira, G.C. Hilton, K.D. Irwin, C.D. Reintsema, L.R. Vale, M.W. Rabin, A. Hoover, C.R. Rudy, M.K. Smith, D.M. Tournear and D.T. Vo. 2005. Development of large arrays of microcalorimeters for precision gamma-ray spectroscopy. Published in The Conference Record of the IEEE Nuclear Science Symposium, Puerto Rico, Oct. 23-29, 2005.

Media Contact:
Laura Ost, laura.ost@nist.gov, (301) 975-4034

Two theoreticians from the National Institute of Standards and Technology (NIST) and Indiana University (IU) have published the most accurate values yet for fundamental atomic properties of a molecule—values calculated from theory alone.

In a recent paper,* James Sims of NIST and Stanley Hagstrom of IU announced a new high-precision calculation of the energy required to pull apart the two atoms in a hydrogen molecule (H₂). Accurate to 1 part in 100 billion, these are the most accurate energy values ever obtained for a molecule of that size, 100 times better than the best previous calculated value or the best experimental value. Their results are intrinsically interesting to astronomers studying galactic clouds of hydrogen, and to anyone else doing precision hydrogen spectroscopy, but the methods they used are perhaps equally important.

The calculation requires solving an approximation of the Schrödinger equation, one of the central equations of quantum mechanics. It can be approximated as the sum of an infinite number of terms, each additional term contributing a bit more to the accuracy of the result. For all but the simplest systems or a relative handful of terms, however, the calculation rapidly becomes impossibly complex. While very precise calculations have been done for systems of just three components such as helium (a nucleus and two electrons), Sims and Hagstrom are the first to reach this level of precision for H₂ with two nuclei and two electrons. Their calculations were carried out to 7,034 terms.

To make the problem computationally practical, Sims and Hagstrom merged two earlier algorithms for these calculations—one which has advantages in ease of calculation, and one which more rapidly achieves accurate results—into a hybrid with some of the advantages of both. They also developed improved computer code for a key computational bottleneck (high-precision solution of the large-scale generalized matrix eigenvalue problem) using parallel processing. The final calculations were run on a 147-processor parallel cluster at NIST over the course of a weekend—on a single processor it would have taken close to six months.

* J. Sims and S. Hagstrom. 2006. High precision variational calculations for the Born-Oppenheimer energies of the ground state of the hydrogen molecule. The Journal of Chemical Physics, 124, 094101 (published online on March 1).

Commerce Secretary Carlos Gutierrez recently approved a new standard to help federal agencies improve their information technology security and comply with the Federal Information Security Management Act (FISMA) of 2002. Federal Information Processing Standard (FIPS) Publication 200, Minimum Security Requirements for Federal Information and Information Systems, is the second of two mandatory security standards required by the FISMA legislation.

FIPS 200 specifies minimum-security requirements for federal information and information systems that are not national security systems and a risk-based process for selecting security controls necessary to satisfy these requirements. Security controls are the management, operational and technical safeguards and countermeasures needed to protect the confidentiality, integrity and availability of a computer system and its information.

FIPS Publication 199, Standards for Security Categorization of Federal Information and Information Systems, requires agencies to categorize their information and information systems as low-impact, moderate-impact or high-impact for the security objectives of confidentiality, integrity and availability. A third publication, Recommended Security Controls for Federal Information Systems (NIST Special Publication 800-53), specifies minimum sets of security controls for information systems and provides guidance on selecting the appropriate controls for 17 security-related areas, including risk assessment, contingency planning, incident response, access control, and identification and authentication.

New data on the properties of potential "liquid lenses" compiled by the National Institute of Standards and Technology (NIST) could help the semiconductor industry continue to shrink feature sizes on computer chips.

In a paper published in the March 10, 2006 issue of Applied Optics,* NIST researchers present newly measured values for key properties of organic solvents and inorganic solutions that might be useful in immersion lithography. Little more than an idea three years ago, immersion lithography is already being commercialized, thanks in part to previously published NIST data. The technique uses liquids to sharpen the focus of patterns used in "printing" semiconductor circuits, much like the eye uses a liquid center to help form images on the retina. Prototype commercial systems use water between the last lens element and the circuit's silicon wafer base, to focus 193-nanometer wavelengths of light down to circuit feature sizes of perhaps 45 nanometers.

The liquids used for immersion lithography must have a high refractive index—the higher the better—which affects how light bends as it crosses interfaces. NIST previously published data on the refractive index of water, which is almost 50 percent higher than that of air. "When we started this work two years ago, you couldn't even find adequate data on water," says Simon Kaplan, lead author of the new paper.

Several companies have proposed proprietary high-index immersion liquids. The NIST work, by contrast, is a fully public report of the key optical properties of a range of fluids. The survey indicates useful trends, such as the fact that refractive index increases with molecular size, and includes data on the effect of temperature on the refractive index, which is crucial in maintaining a sharp focus during the printing process. The data may help other researchers identify useful liquids or calibrate their own measurements.

* S.G. Kaplan and J.H. Burnett. 2006. Optical properties of fluids for 248 nm and 193 nm immersion photolithography. Applied Optics. Posted online March 10.

Changes Approved to Federal ID Standard

U.S. Commerce Secretary Carlos Gutierrez has approved a revision to Federal Information Processing Standard 201 (FIPS 201), a standard issued in February 2005 for a smart card-based form of identification for federal employees and contractors called the Personal Identity Verification (PIV) card. The revision was made to clarify the identity proofing and registration process that federal agencies must follow when issuing a PIV card.

The revision makes the standard consistent with guidance issued to agencies by the Office of Management and Budget in August 2005. The revised standard, FIPS 201-1, Personal Identity Verification (PIV) of Federal Employees and Contractors, is available at http://csrc.nist.gov/publications/fips/#fips201-1.

The National Aeronautics and Space Administration (NASA) recently announced that a team of researchers at the National Institute of Standards and Technology (NIST) has been awarded 1 million central processing unit (CPU) hours on the Columbia supercomputer at the space agency's Ames Research Center. The allocation is one of four awards of supercomputer time given in a peer-reviewed competition for "grand challenge" computational science projects led by researchers outside NASA.

The NIST team of William George, Judith Terrill, Nicos Martys and Edward Garboczi will use the granted time to study the flow, dispersion and merging of densely suspended, diversely sized and shaped materials (primarily cement in concrete) under a variety of conditions. Access to the NASA machine will allow computer modeling at a level and range impossible with existing facilities at NIST. The ability to better model real conditions will significantly improve the scientific basis for prediction and measurement of the flow properties of concrete. A NASA press release on the award is at www.nasa.gov/home/hqnews/2006/mar/HQ_06086_super_computer_time.html.

The National Institute of Standards and Technology (NIST) is soliciting “a few good nucleic acid sequences” for possible inclusion in a library of RNA reference materials for use in gene expression research.

NIST is building the library as part of a program with the External RNA Controls Consortium (ERCC) to develop a set of well-characterized RNA sequences that can be used as a simple but reliable check on the performance of DNA microarrays, quantitative Reverse Transcriptase Polymerase Chain Reaction (QRT-PCR) experiments, and other gene expression assays. (See “Consortium Seeks Comment on Gene Expression Roadmap” www.nist.gov/public_affairs/techbeat/tb2005_0826.htm#gene.)

The sequences, which will be used in a manner mimicking portions of typical mammalian mRNA transcripts, must be released to the public domain. The sequence library will be used to assemble RNA materials for the planned test suite of external RNA controls. To ensure the broadest possible base library of sequences, NIST has extended the deadline for inclusion in the first round of testing to April 28, 2006. For details, see “Notice of Intent To Establish the NIST Nucleic Acid Sequence Library,” Federal Register, Feb. 28, 2006 (Volume 71, Number 39), pp 10012-10013.

The National Earthquake Hazards Reduction Program (NEHRP) is the federal government's program to reduce the risks to life and property from earthquakes. The four agencies making up NEHRP—the Federal Emergency Management Agency (FEMA), the United States Geological Survey (USGS), the National Science Foundation (NSF) and the organization's lead agency, the National Institute of Standards and Technology (NIST)—are seeking the public’s assistance in updating the program’s 2001-2005 strategic plan to create the plan for 2006-2010. Anyone interested in participating in this process may download the 2001-2005 plan from the NEHRP Web site (http://www.nehrp.gov ) and suggest updates via a public comment form at the same site. The form may be e-mailed, faxed or sent by regular mail to NEHRP. NEHRP will accept comments through May 26, 2006.

Additionally, the NEHRP agencies will host an open forum at the 100th Anniversary 1906 San Francisco Earthquake Conference on April 17, 2006. At the forum, each of the four NEHRP agencies will present a brief summary of its current activities and then take comments from conference attendees on NEHRP performance and direction. More information is available at http://www.1906eqconf.org.