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Projects/Programs

Topic Area
Displaying 51 - 75 of 470

Basic Metrology: NIST-3 Standard Ampoules and Automatic Tip Sealing

Ongoing
Report NISTIR 8254 referenced above was intended to document and archive the historical record for the acquisition and testing of standardized ampoules used by the NIST / NBS Radioactivity Group since the 1950s. These ampoules were intended to contain 5 mL of solutions of radionuclides decaying with

Basic Metrology: Primary Standards for Radionuclides

Ongoing
As the National Metrology Institute (NMI) for the US, NIST is responsible for realizing the SI units. The derived SI unit for activity of a radionuclide is the becquerel, Bq. NIST has a proud history of contributing to the development of new and improved primary standardization methods for the Bq to

Basic Metrology: Recent Primary SRM Standardizations

Ongoing
SRM No. Radionuclide Reference Date Method Used Relative expanded uncertainty ( k = 2) References 4332f Americium-243 8 March 2024 The certified massic activity for 243Am was obtained by 4pab LS spectrometry with two commercial LS counters. The beta detection efficiencies for the 243Am daughter were

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

Basic Metrology: Standard Reference Data on Radiation Interactions

Ongoing
This work continues in the Division's Photon and Charged-Particle Data Center. The compilations of the Data Center rely heavily on evaluating measurements and on their synthesis with available theory to extend the data and provide for comprehensive coverage over broad ranges of energy and materials

BIB-trap detector

Ongoing
Limitations of Standard BIB Detectors Currently available BIB detectors exhibit excellent detectivity, but are limited in their use for spectral calibrations by detection inefficiency and spectral response inhomogeneity. The maximum quantum efficiency of these doped silicon devices is near 60%

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

Bioelectronic Sensors for Tissue/Organ-on-a-Chip Systems

Ongoing
We apply our expertise in micro/nanofabrication, electrokinetics and cell-based assays to develop bioelectronic sensors in microfluidic platforms. We are working on a platform that entraps cells for electrochemical monitoring in an environment that has mechanical properties more similar to those

Biomolecular assembly

Ongoing
The integration of new materials or components into the design and production of diverse nanotechnologies, ranging from electronic devices to therapeutic particles, requires a quantitative understanding of process–structure–property relationships, as well as interactions with other entities in 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

Calculation of optical constants and dielectric response

Ongoing
By optical properties, we mean those of the following sort: the index of refraction n and the index of absorption k, from which one can calculate the dielectric function, loss function, absorption coefficient, reflectance, and so forth from standard formulas. All of these quantities, it should be

Calibration of Force Transducers

Ongoing
The calibration report describes the relationship between the applied force and the measured deformation, either in electrical or mechanical units. A transducer can be calibrated using (1) a readout device furnished by the customer, in which case the transducer and the readout device are calibrated

Calibration of Mass Standards

Ongoing
Redefinition of the Kilogram and Consensus Value of the Kilogram The unit of mass was redefined in May 2019 as part of a general revision to the International System of Units (SI). See SI Redefinition. The kilogram is now defined by the Planck constant. The International Prototype Kilogram (IPK) no

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 Services: Low-Energy Photon Brachytherapy Sources

Ongoing
Since 1999, over 1,500 seeds of more than 40 different designs from 18 manufacturers have been calibrated using the WAFAC. On-site characterization at seed manufacturing plants for quality control, as well as at therapy clinics for treatment planning, relies on well-ionization chamber measurements

Calibration Services: New Calibration Facility for X-Ray Air Kerma

Ongoing
The NIST x-ray calibration facility is composed of a suite of rooms that includes the 11 m by 7 m calibration range, a dedicated equipment room, connected by custom shielding ports for communication with the x-ray tubes in the radiation area, an operator control center with a viewing window and