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Projects/Programs

Topic Area
Displaying 426 - 450 of 469
spectrophotometric processes illustration

Spectrophotometry

Ongoing
NIST uses spectrophotometric techniques to measure the optical properties of materials for dissemination of national measurement scales to its stakeholders and advancing the development of standards, measurement methods, and modeling capabilities. The beneficiaries of these activities include the

Spectroradiometry of sources

Ongoing
The spectral radiance sources in the form of tungsten-strip lamps and integrating-sphere sources are calibrated in the Facility for Spectroradiometric Calibrations (FASCAL). The measurements are performed by the use of a prism-grating double monochromator whose spectral radiance responsivity is

Spinor Condensates and Ultracold Collisions

Ongoing
A Bose-Einstein condensate (BEC) collapses the wavefunctions of many particles in to a single quantum state. In a spinor BEC the atoms can be in a superposition of internal quantum states. Thus, a BEC of spin-1 particles, like the F = 1 ground state of Na atoms, can be thought of as being a single
Schematic of device structure designed to utilize novel spin current generation in a ferromagnet (FM) to achieve electrical switching of a perpendicularly magnetized FM layer

Spin-orbit interaction in devices and quantum materials

Ongoing
The spin degree of freedom can provide a basis for next-generation electronic devices. Spintronic devices typically include materials with magnetic ordering, such as ferromagnets or antiferromagnets. The state of the magnetization influences charge and spin current through an effect known as
Fig. 1. Die containing 285 superparamagnetic tunnel junctions.

Spintronics for Neuromorphic Computing

Ongoing
Magnetic tunnel junctions (see Fig. 1) consist of two thin films of ferromagnetic material separated by a few atomic layers of an insulating material. The insulator is so thin that electrons can tunnel quantum mechanically through it. The rate at which the electrons tunnel is affected by the

Standard Reference Materials: Standardization of 232U (SRM 4324c)

Ongoing
The certified massic activity for 232U was obtained by 4παβ LS spectrometry with two commercial LS counters. The beta detection efficiencies for the 232U daughters were calculated using the MICELLE2 code for the CIEMAT/NIST efficiency tracing (CNET) method with composition-matched LS cocktails of a

Standard Reference Materials: Standardization of 243Am (SRM 4332f)

Ongoing
The certified massic activity for 243Am was obtained by 4παβ LS spectrometry with two commercial LS counters. The beta detection efficiencies for the 243Am daughter ( 239Np) were calculated using the CN2003 code for the CIEMAT/NIST efficiency tracing (CNET) method with composition-matched LS

Standard Reference Materials: Standardization of 239Pu (SRM 4330d)

Ongoing
The certified massic activity for 239Pu was obtained by 4πα liquid scintillation (LS) spectrometry with two commercial LS counters. Confirmatory measurements were performed by LS counting comparative measurements against SRM 4330d, which was also standardized in 2009 by 4pa liquid scintillation (LS)

Structure, Defects, and Scattering in Graphene

Completed
The graphene honeycomb lattice is a key element in determining many of graphene's spectacular properties, which are desirable for a host of electronic applications. The graphene 6-fold symmetric lattice gives rise to charge carriers behaving like light-waves having zero mass. The charge carriers in

Subspace-Informed Deep Learning Solutions for Nanoscale Microscopy

Ongoing
Cutting-edge nanoscale microscopy techniques such as near-field scanning microwave microscopy (NSMM) and atom probe tomography (APT) enable a multi-dimensional virtual representation of an artifact to be constructed from a set of experimental measurements. These imaging techniques, which are
solar simulator graph

Super-Continuum Laser Solar Simulator

Completed
The design of the super-continuum solar simulator is shown below. Light is produced from 450 nm to 2400 nm in sub-nanosecond pulses at a repetition rate of 80 MHz. The total irradiance is sufficient to illuminate a 1 cm 2 cell at more than 1-sun. Initial tests have confirmed that solar cells respond
Prototype standard for super-resolution optical microscopy

Super-resolution optical microscopy

Ongoing
Optical microscopy has been fundamental to science for four centuries, enabling resolution of the microscale. In the last two decades, scientists have made the remarkable discovery that super-resolution methods can extend optical microscopy deep into the nanoscale. It is now possible to detect and
water flow standard

Temperature Sensitivity of Liquid Flow Meters

Completed
The Fluid Metrology Group is using NIST’s 15 kg/s water flow standard (Fig. 1) to test how coriolis meters are affected by liquid and environment temperatures. The water flow standard is a closed-loop, dynamic liquid flow calibration facility that is fully automated. For this work, calibrations were
Fig. 1. Time re-Envisioned: Not a biproduct of computation but the domain in which information is encoded. Leads to different mathematical functions becoming energy efficient primitives.

Temporal Computing

Ongoing
In standard integrated circuits, information that is coded as ones and zeros is implemented by voltages on wires being high or low. The circuits consume energy during transitions between these voltages. Binary numbers have a voltage per bit so there are a lot of transitions each time a number
Passive millimeter-wave image of concealed contraband (handgun and ceramic knife).

Terahertz Imaging and Sources

Ongoing
Over the past several years, we have focused on bolometric detection of THz radiation. Our initial work on cryogenic detectors has been extended to antenna-coupled bolometers operating at room temperature. These detectors provide a rugged, low-cost alternative for homeland security applications; e.g
Schematic of a radial p- n- Junction

Theory and Modeling of Materials for Renewable Energy

Completed
Nanostructured materials offer potential benefits for a range of renewable energy applications that rely critically on interfaces for separating charges, including photovoltaics, thermoelectrics, and electrochemical energy storage. The use of nanostructures allows scientists and engineers to

Theory of the optical properties of materials

Ongoing
Around 1998, first-principles calculation of optical constants and dielectric response began to include excitonic effects. Beginning with simple, wide-gap insulators and semiconductors, the field has progressed to studying more complex materials, clusters, and so forth. In the area of core
A current (white arrow) flowing through a tantalum film generates a current of spins (dark blue arrows) that impinges on the ferromagnetic cobalt iron boron layer and causes the magnetization (gold arrow) to charge directions (light blue arrow).

Theory of Spin-Orbit Torque

Completed
A ferromagnetic material such as iron acquires its magnetization because the magnetic orientation of its constituent atoms all line up in the same way. Because individual electrons also have an intrinsic magnetic moment – which is often referred to as the electron “spin” - they can interact with
triple point cell

Thermometry

Ongoing
The NIST Thermodynamic Metrology Group supports industry and advances measurement science through an extensive suite of thermometry calibration services as well as research projects aimed at improving the utility for the International Temperature Scale. We also develop guidelines, and contribute to
David Gundlach

Thin Film Electronics (Archived)

Completed
Today's electronics have reached a point where sheer computation power has yielded to combined form and function as the key driver of large consumer markets. The demand for portable and pervasive electronics with greater functionality promises significant changes over the next decades in how society
The excellent agreement of measured and simulated TSOM images allow for more reliable quantitative results

Three-Dimensional Nanometer Metrology

Ongoing
Important physical and chemical properties of nanometer scale devices and structures depend on their shape and size. The benefits of nano are already increasing many applications, and are expected to grow significantly. For these applications, measurement accuracy is a fundamental measurement

THz Detection of Corrosion on Rebar Embedded in Concrete

Ongoing
We developed a new technology to detect and quantify the extent of corrosion in embedded rebar using Terahertz (THz) and microwave spectroscopies. This new method exploits the likelihood that a number of iron corrosion products are antiferromagnetic and absorb THz and microwave radiation. In this
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