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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

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
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
lumped element resonant circuit illustration

Applied: Quantum Sensors for Charged Particle Detection

Ongoing
Quantum cryogenic detectors have proven very promising for x-ray and gamma-ray spectroscopy. The suppression of thermal noise due to cryogenic (sub-1K) temperatures leads to excellent energy resolution while still allowing for large collection areas and high absorption efficiency. Specifically, the

Software

Main tab of DataScripting program

DataScripting

DataScripting is a data acquisition program with graphical user interface written in C# that is used as the instrument control program for the NIST Neutron

Tools and Instruments

Neutron imaging facility

Neutron Imaging Facility (NIF)

Summary The NIST Neutron Imaging Facility provides users with a unique “plug and play” approach to imaging operating fuel cells, electrolyzers, and lithium-ion
conventional radiography configuration

Cold Neutron Imaging Instrument

The Cold Neutron Imaging Instrument (CNII) was designed to be a flexible space to test, develop, and employ novel neutron imaging methods to realize different
lens coupled camera detector box

Neutron Imaging Detector Suite

The most commonly used detector at the NIST imaging beamlines is a lens coupled camera detector box shown in Figure 1. The spatial resolution and field-of-view

Awards

Press Coverage

When an ordinary beam of neutrons strikes the team’s silicon grating, the millions of scored lines on the grating convert the neutrons into an Airy beam, whose wavefront travels along a parabolic path. The triangular shapes on the detector match the predicted behavior of an Airy beam, offering evidence of the team’s success.

Neutron Airy beams make their debut

Physics World
Physicists have succeeded in making neutrons travel in a curved parabolic waveform known as an Airy beam. This behaviour, which had previously been observed in

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

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