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Projects/Programs

    Displaying 26 - 50 of 172

    Basic Metrology: High-Resolution X-Ray Spectroscopy

    Ongoing
    X-ray sources of interest include Electron Beam Ion Trap (EBIT), Electron Cyclotron Resonance Ion Source (ECRIS), and laser-produced plasma ion sources, including the new generation of petawatt lasers. In support of these efforts, we also maintain laboratory x-ray sources from 1 keV to 300 keV

    Basic Metrology: Neutron Cross Section Standards

    Ongoing
    Data from a number of NIST collaborations have produced measurements for the standards program. Measurements are underway now at NIST of the 6Li(n,t) and 235U(n,f) cross sections at sub-thermal energy. These will be the first absolute measurements of these cross sections in this energy region

    Basic Metrology: Remote Sensing Methods for Imaging Dose to Water

    Ongoing
    Ultrasound and laser interferometry, widely used for nondestructive testing and remote sensing applications, are being used here to measure dose distributions in irradiated water phantoms by taking advantage of temperature dependence in the speed of sound and optical index of refraction of water

    Bilateral Comparison of Spectral Responsivity in the Vacuum-Ultraviolet

    Completed
    The last decade has seen numerous key comparisons in the field of photometry and radiometry between different national metrology institutes (NMIs) in the context of the Mutual Recognition Arrangement. At first, these comparisons were restricted to wavelengths longer than 200 nm, with just the

    Birefringence Properties of Optical Materials (0.12 μm – 2 μm)

    Ongoing
    For crystals with non-cubic crystal symmetry, we make accurate measurements of the birefringence and its wavelength dispersion (0.12 μm – 15 μm) by separate index measurements of the two polarizations using the NIST's minimum deviation refractometry system. In nominally isotropic materials (cubic

    Boulder Microfabrication Facility

    Ongoing
    The Boulder Microfabrication Facility (BMF) is a 1700 m 2 (18,000 ft 2), ISO class 5 (class 100) clean room dedicated to providing state-of-the-art micro- and nano-fabrication capabilities to meet the microelectronic and microelectromechanical systems needs of NIST-Boulder staff members and their

    Calibration Services: High-Dose Dosimetry

    Ongoing
    NIST developed the alanine dosimetry system in the early 1990's to replace radiochromic dye film dosimeters. Later in the decade the alanine system was firmly established as a transfer service for high-dose radiation dosimetry and an integral part of the internal calibration scheme supporting these

    Calibration of Space Weather Observational Instruments at NIST

    Ongoing
    Space-weather events are naturally occurring phenomena caused by activity on the Sun that affect us here on Earth. Solar storms can impact technology we rely on daily, like e.g. the Global Positioning System (GPS), communication satellites, and electric power grids. Various phenomena that originate

    Calibrations: Californium Neutron Irradiation Facility

    Ongoing
    A high-activity Cf-252 source (~10 10 neutrons/s as of May 2024) is housed in a large (approximately 15 m x 10 m x 10 m high) room with concrete walls, floor, and ceiling (see photograph) at a depth of 10 meters-water-equivalent. In addition, there are two monoenergetic neutron generators for 2.5

    Chip-scale ultraprecise laser technologies

    Ongoing
    Lasers with high spectral purity are used in a diverse application space, including coherent high-speed communications, physical sensing, and manipulation of quantum systems. Lab bench scale Fabry-Perot cavities based on sophisticated vibration, thermal, and atmospheric isolation have made possible

    CODATA values of the fundamental physical constants

    Ongoing
    CODATA recommended values of the constants Database of references for data on the constants Publications: Reviews of Modern Physics ( 1998) ( 2002) ( 2006) ( 2010) ( 2014) Journal of Physical and Chemical Reference Data ( 1998) ( 2006) ( 2010) Resource Letter FC-1: The physics of fundamental

    Compact strontium optical clock with integrated photonics

    Ongoing
    The development of a liter-scale apparatus to produce Sr, would enable highly accurate, transportable optical clocks based on their ultra-narrow optical transition. However, straightforward miniaturization of the traditional optical infrastructure necessary to implement multi-step laser cooling has

    Compact Ultrastable Optical References

    Ongoing
    At the heart of any stable laser is a reference cavity resonator. By locking a laser’s frequency to a reference cavity mode, the laser inherits the resonator’s stability. These stable lasers can then be used in various sensing and spectroscopy applications, including in optical atomic clocks and

    Comparisons (Archive): International Comparison of Tc-99 Activity

    Completed
    Measurements by NIST on the solution were performed by three methods: viz., liquid scintillation (LS) standardizations (with 3H-standard efficiency tracing); with triple-to-double-coincidence ratio (TDCR) method; and with by 4ηβ(LS)-γ(NaI) live-timed anticoincidence (LTAC) measurements. Impurities