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Physical Measurement Laboratory

Radiation Physics Division

The Division develops, maintains and disseminates the national measurement standards for ionizing radiation and radioactivity, and methods and models to address related applications.

Cold neutron imaging facility
On the Road to a Neutron Microscope: First Light for World-Class Neutron Imaging Facility
True Bq
True Becquerel - A New Paradigm for 21st Century Radioactivity Measurements
NIST Calibrates Quartz Crystals for Fusion Device
NIST Calibrates Quartz Crystals for Fusion Device

In addition to our mission to realize the Système International (SI) units for absorbed dose (the gray) and activity (the becquerel), we maintain an active research programs in terahertz spectroscopy, neutron physics, radiation dosimetry, and radionuclide metrology. We are also active in over-arching programmatic efforts in medical physics to support medical imaging and therapeutics, standards and test procedures for chemical/biological/radiation/nuclear/explosives countermeasures in homeland security, measurement assurance and standards to support environmental stewardship and the nuclear energy and radiation industries, and methods in applications of ionizing radiation in advanced manufacturing. We promote the accurate and meaningful measurements of dosimetric quantities pertaining to ionizing radiation (x and gamma rays, electrons, and energetic, positively charged particles) and provide measurement services, standards, and fundamental research to support neutron technology and neutron physics for industrial research and development through neutron dosimetry, calibration of neutron survey instruments, and development of neutron sources. We are also responsible for developing metrological techniques to standardize new radionuclides for research and for exploring radiation and nuclear applications, including through development and distribution of the Standard Reference Materials for radioactivity in the U.S..

News and Updates

skyrmions

Imaging the Elusive Skyrmion

Scientists at the National Institute of Standards and Technology (NIST) with colleagues elsewhere have employed neutron imaging and a reconstruction algorithm

Projects and Programs

Accelerator Facilities

Ongoing
The Division's accelerator facilities continue to support a broad range of research efforts in the areas of industrial and medical dosimetry, homeland security, radiation-hardness testing and materials-effects studies. Topics of research during this reporting period included: (1) a broad-energy
liquid scintillator detector

Applied: Methods in Neutron Detection and Spectroscopy

Completed
Energetic neutrons (> 1 MeV) play a variety of important roles from dosimetry to the fundamental sciences. Fast neutrons can be an often under-appreciated but significant biological dose from accelerators and nuclear facilities, serve as a way of detecting nuclear materials, and can often yield
incident neutrons

Applied: Photon Assisted Neutron Detector (PhAND)

Ongoing
Due to the simplicity of the PhAND physics package, any number of detector configurations can be deployed. Basic detector operation is illustrated in Fig. 1. Incident neutrons are absorbed in a 10B film and the charged daughter products (𝜶 7Li) enter the surrounding xenon where they produce xenon

Tools and Instruments

NIF

Neutron Imaging Facility (NIF)

Neutron Imaging, an Essential Tool for the Hydrogen Economy The problem that the NIST Neutron Imaging Facility (NIF) can address that directly impacts the

Awards

Press Coverage

Patents

A list of radiation-induced materials modifications that are NIST traceable

Photonic Dosimeter and Process for Performing Dosimetry

NIST Inventors
Ronald Tosh , Zeeshan Ahmed , Ryan P. Fitzgerald and Nikolai Klimov
A photonic dosimeter accrues cumulative dose and includes: a substrate; a waveguide disposed on the substrate and that: receives a primary input light; transmits secondary input light from the primary input light to a dosimatrix; receives a secondary output light from the dosimatrix; and produces

Products and Services

Facilities

Contacts

Division Chief

Group Leaders