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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.

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

Spotlight: Radiometric Dating

Dating can be complicated. Our team uses this instrument — a live-timed anticoincidence counter — to figure the decay rate of an isotope, which we can then use

Projects and Programs

Industrial: Enhanced X-Ray Imaging

This project pursues enhanced x-ray image acquisition and analysis methods that are applicable to, for example, security and medical applications of x-ray

Tools and Instruments

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

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

Awards

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
Patent Description Radiation-induced materials modification is ubiquitous. These applications rely on dosimetry to reliably deliver the desired amount of radiation to the right place. Currently the dosimetry standard is based on calorimetry of a large water phantom irradiated exclusively by Co-60

Contacts

Division Chief and Deputy Division Chief