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Physical Measurement Laboratory

Radiation Physics Division

Projects/Programs

Displaying 101 - 119 of 119

Medical: Characterization of Dosimeters Used in Computed Tomography

Completed
The Dosimetry Group of the Radiation Physics Division has an on-going collaboration with the FDA, NIH, and the Walter Reed National Military Medical Center to characterize clinical dosimeters for the purpose of monitoring the radiation dose delivered to patients during computed tomography (CT) exams
dose calibrators

Medical: Standards for Clinical Radionuclide Calibrators

Ongoing
In nuclear medicine, clinical activity measurements are typically made using commercially available radionuclide calibrators (also referred to as “dose calibrators”) which incorporate a reentrant 4π ionization chamber and an electrometer. The current measured by these calibrators is translated into
Metrology is the foundation of the entire semiconductor enterprise. Standards provide the highest “value added” of all processes.

Metrology of Purity and Contaminants in Solid Materials

Ongoing
Purity evaluations of high-purity bulk materials used in chips manufacturing are calibrated against reference materials that are often not matrix-matched to the materials under test. In other words, differences in the compositions of the calibrants and the samples being analyzed can result in large

New Reference Standards for Digital Mammography

Ongoing
These beams will provide FDA inspectors, ionization chamber manufacturers, and calibration facilities with the spectra that best represent what is used in clinics. These new reference radiation techniques will be available for calibrations and the FDA-MQSA proficiency tests. The beam parameters are
Dosimetry_ResearchandMetrology_PhotonAbsorbedDose_pic_Tosh

Photon Absorbed-Dose-to-Water Primary Standards

Ongoing
Modeling of accumulated-dose dependence in the heat defect of H2/O2 exhibits expected peak behavior in qualitative agreement with experiment, and is being further refined for purposes of reducing the associated relative uncertainty from its present value of 0.3 %. Studies to quantify the possible
photonic calorimeter/dosimeter

Photonic Dosimetry

Ongoing
With this effort, NIST is responding to industry needs for traceable, measurement solutions that can resolve spatial variations of absorbed dose at the level of individual components on a silicon wafer or bacteria on surgical instruments. Presently, there is only limited traceability to national
Photo of DT702

Radiation Protection: Support of the Navy Dosimetry Program

Ongoing
Since 2010, the U.S. Navy has adopted a personal dosimeter designated as the model DT-702/PD, which was demonstrated to have an improved accuracy, energy discrimination and a lower detection limit than prior Navy designated models such as the DT-5XX/PD and DT-6XX/PD series. This dosimeter is used to
cavity chamber

Security: Air-Kerma Measurements in High Energy X-ray Beams

Completed
X rays are used for imaging the contents of vehicles and cargo. Because of the need to penetrate through the thickness of the wall of containers and vehicles in addition to the objects contained within, these systems rely on the use of penetrating radiation such as high energy megavoltage x rays
Neutron Detector Replacement

Security (Archive): Neutron Detector Replacement Program

Completed
This course of action has included an intense sequence of tests of alternative technologies performed at the Los Alamos National Laboratory and the Nevada National Security Site. NIST has been integral to all phases of these testing programs, including evaluation of submitted detectors, design and
nuclear forensics reference material program icons

Security: Nuclear Forensics Reference Material (RM) Program

Ongoing
NIST coordinates the production and characterization of nuclear forensics reference materials (NFRMs), which are vital for making precise and accurate measurements of nuclear materials. These materials will help ensure that measurements of nuclear material evidence are highly reliable, are traceable

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)