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Radioactivity Group

Welcome

The Radioactivity Group develops and improves the metrological techniques used for the standardization of radionuclides, and carries out a wide range of programs in low-level standards for environmental measurements and monitoring, standards for nuclear medicine, standards and testing criteria for radiological instrumentation used for security, and radionuclide metrology. Its mission is to develop, maintain, and disseminate radioactivity standards, develop and apply radioactivity measurement techniques, and engage in research to meet the requirements for new standards. Our participation in international comparison exercises has kept us abreast of efforts of other laboratories and helped us to maintain our own capabilities. 

We continue to lead the national effort, in collaboration with the Department of Homeland Security, to develop standards and protocols for radiation instrumentation for early and emergency responders. We have developed an accreditation program with NVLAP for instrument testing. We are also spearheading the development of ANSI standards and testing protocols for spectroscopic portal monitors, neutron detectors, x-ray and high energy gamma-ray interrogation methods, x-ray imaging, data formats for instrumentation data output, and training standards for responders. 

The Group continues to lead an internationally-recognized program for standards in nuclear medicine, providing the national standards for radionuclides used in 13 million diagnostic procedures and 200,000 therapeutic nuclear medicine procedures annually in the US. Primary standards of two radionuclides, 223Ra and 68Ge have been developed. A new initiative, aimed at establishing standards and measurement support to improve accuracy and consistency in quantitative Positron Emission Tomography/X-ray Computed Tomography (PET/CT) and Single-Photon Emission Computed Tomography (SPECT) imaging, is well underway. 

The Group's environmental program leads to community in low-level and natural matrix material measurements and standardization, and continues to be heavily involved in the world-wide measurement of environmental-level radionuclide dispersal and contamination through a large number of international intercomparisons and traceability programs and SRMs. A Radioanalytical Emergency Procedures Manual Database has been developed to assist organizations preparing for emergency response. 

Revitalization of our basic metrology capabilities has involved extensive work in many areas. In addition to introducing the TDCR method to routine use at NIST, work is also progressing on the construction of second-generation TDCR system. The principle method of primary standardization at NIST is live-timed 4??? anticoincidence counting. During the past two years, NIST researchers have adapted this method to perform primary measurements on a variety of radionuclides. A new automated ionization chamber has been developed at NIST to measure up to 100 samples with programmable sample queuing, sample handling and measurement parameters.

Programs/Projects

Test and Evaluation Protocols for ANSI/IEEE N42 Standards—The purpose of these test and evaluation protocols is to provide additional information to the published ANSI/IEEE N42 series for homeland security applications for radiation detection systems.

Radioactivity Standard Reference Material Program—The Standard Reference Materials Program of the National Institute of Standards and Technology (NIST) provides science, industry, and government with a central source of well-characterized …

ANSI N42.42 Standard—The purpose of the N42 data format is to facilitate manufacturer-independent transfer of information from radiation measurement instruments for use in homeland security applications as well as for …

IECn42—The purpose of the IEC 62755 standard N42 data format is to facilitate manufacturer-independent transfer of information from radiation measurement instruments used for detection of illicit …

Radionuclides by Anticoincidence Counting—The standardization of radionuclides by primary methods is the foundation for all the standards and services provided by the NIST radioactivity group.

Ge-68, PET Scanner Clinical Trials—The interpretation of quantitative imaging data obtained from Positron Emission Tomography (PET) studies requires an understanding of the measurement variability due to instrumental effects, …

International Comparison of Tc-99—An international measurement comparison for a 99Tc solution hosted by National Physical Laboratory (NPL) of the UK, (CCRI(II)K-2.99Tc comparison) was completed.   800x600   Normal   0           …

Liquid Scintillation Counting—The triple-to-double coincidence ratio (TDCR) method of liquid scintillation counting employs three detectors to facilitate the experimental determination of counting efficiencies so that activity …

Ba-133 Standard—The International Atomic Energy Agency (IAEA) recently initiated a Cooperative Research Project  (CRP) entitled “Development of Quantitative Nuclear Medicine Imaging for Patient Specific Dosimetry” …

Automated Multi-Sample Ionization Chamber for Radioactivity Standards—NIST radioactivity standards for gamma-ray emitting radionuclides are maintained as calibration factors for an automated ionization chamber.

International Comparison of Lu-177—There has been increasing interest during the past 10 years in the use of 177Lu for radionuclide-based radiotherapy for certain types of cancers. Accurate administrations of drugs using this …

Standards for Clinical Radionuclide Calibrators—In nuclear medicine clinics, activity measurements are typically made using commercially available radionuclide calibrators which incorporate a reentrant 4Π ionization chamber and an electrometer.

Micelle Effects in Liquid Scintillation Counting—Commercially available scintillates (often referred to by manufacturers as “cocktails”) for liquid scintillation (LS) counting are complex concoctions of alcohols, phosphates, polymers, and salts …

Testing of Radiation Detection Systems—NIST is working together with the Department of Homeland Security (DHS) Domestic Nuclear Detection Office (DNDO) in testing radiation detection equipment for homeland security applications. 

Absolute Ag108 Characterization Based on Gamma-Gamma Coincident Detection by Two Nai (TI) Detectors—A two-dimensional analysis of three coincident gamma-rays in 108Agm decay, detected by two NaI(Tl) scintillation detectors, allows a direct measurement of the source activity

Quantification of the Alpha Wall Effect in Liquid Scintillation Counting—A long-standing uncertainty in liquid scintillation (LS) counting has been the possible loss of counting efficiency. 

Primary Radioactivity Standardization of Ni-63—Ni-63 is of considerable interest and importance in radionuclidic metrology as well as for radiation protection surveillance around nuclear facilities.

Components of Variance in Liquid Scintillation Counting—As part of the standardization of the 239Pu solution that was disseminated by NIST as Standard Reference Material (SRM) 4330C, a detailed study was performed to better understand and ascertain how …

Radon Binding to Water-Soluble Cryptophane—Collaboration on investigating the thermodynamics of radon binding with a new and novel class of cryptophane molecules is currently underway with researchers from the University of Pennsylvania …

New Statistical Analysis Tools—Members of the Radioactivity Group (RG) have been actively collaborating with statisticians in the NIST Statistical Engineering Division to identify new tools that would be of assistance in …

Technetium-99m Primary Standardization and International Comparison—Technetium-99m (99mTc) is used in two-thirds of all diagnostic nuclear medicine procedures in the United States.

International Comparison of Pu-241—All of the plutonium isotopes, which have a very high biotoxicity, are man-made and result from various nuclear activities. Plutonium-241 is a very low-energy beta emitter with Eß(max) = (20.8 ± …

Blind Measurement Comparisons of the USA and UK Pb-210 National Standards—The National Institute of Standards and Technology (NIST), Radioactivity Group, and the National Physical Laboratory (NPL) of the UK, and the national metrology laboratories of their respective …

New Standardization of Ra-228—Measurements of radium isotopes in the naturally-occurring radioactive decay chains (i.e., 235U, 238U, and 232Th) are exceedingly important for various applications related to geochemical studies.  

Standardization of Am-243—A new standard solution of 243Am, an important radionuclide for the US and international environmental-measurements communities, was developed and disseminated at NIST as SRM 4332E. 

NIST Laboratory for Quantitative PET-CT Imaging—As part of a NIST-wide effort to develop a metrological infrastructure for quantitative medical imaging, the Radioactivity Group has recently established a dedicated facility to support its efforts …

Secondary Standards for Ra223—223Ra is being evaluated as a radiopharmaceutical for the treatment of skeletal metastases.  As an alkaline earth metal, Ra exhibits intrinsic bone-seeking behavior, so that ligation to complex …

Shellfish Natural Matrix Radionuclide Standard Reference Material 4358—This Standard Reference Material (SRM) has been developed in cooperation with member laboratories of the International Committee for Radionuclide Metrology and other experienced metrology …

Radionuclide in Soil Reference Materials—Consequence management of a radiological incident requires rapid information about the nuclides, amount, dispersion, and speciation for the determination of sheltering-in-place, evacuation, food …

Gamma-ray Spectrometry System—A new silicon detector for calibration of low energy gamma-ray emitting sources used for nuclear power plants, medical and homeland security applications was installed and calibrated as part of the …

Separation and Purification of Ra-228 for SRM 4339B—The US Environmental Protection Agency (USEPA) maximum contaminant level for combined 226Ra and 228Ra in drinking water is 5 picocuries (37 mBq) per liter. Sensitive radioanalytical methods for …

Illicit Trafficking of Radioactive Materials—The National Institute of Standard and Technology (NIST) is working in the development of ANSI/IEEE and IEC standard for the detection of illicit trafficking of radioactive materials for homeland …

National Technical Nuclear Forensics CRMs—The U.S. Department of Homeland Security (DHS) is committed to using cutting-edge technologies and scientific talent in its quest to make America safer.  

Active Interrogation Standards—Active interrogation involves directing nuclear radiation into a closed container and measuring secondary radiations to gain information about the contents of the container.

The Urgent Requirements for New Radioanalytical CRMs—A multi-agency workshop was held from 25–27 August 2009, at the National Institute of Standards and Technology (NIST), to identify and prioritize the development of radioanalytical Certified …

Development of Epoxy Based Ge-68 Standard Phantom Sources—The use of imaging data for staging of disease, treatment planning, and monitoring of patient response continues to increase. In these types of studies, where comparability between successive scans …

Highlights

For the Radioactivity Group

 
Contact

Unterweger 

Michael Unterweger, Group Leader

301-975-5536 Telephone
301-975-5530 Group Secretary
301-926-7416 Facsimile

100 Bureau Drive, M/S 8462
Gaithersburg, MD 20899-8462

Radioactivity Staff Directory