System of high-purity germanium detectors for the detection and measurement of inhaled radionuclides. [/sup 239/Pu and /sup 240/Pu and /sup 241/Am]

Conference · Sun Jan 01 04:00:00 EST 1978

OSTI ID:6787291

Falk, R. B.; Tyree, W. H.; Wood, C. B.; Lagerquist, C. R.

A system of eight high-purity germanium detectors mounted, four each, as arrays on two downward-looking cryostats is described. This system is designed to measure photons emitted by inhaled radionuclides and is efficient for photon energies between 10 keV and 200 keV. In routine operation since October 1976, the system is used mainly to detect and measure inhaled plutonium and americium. Each of the eight detectors has a surface area of 10 cm/sup 2/ and a resolution of 650 eV full-width half-maximum or better at 60 keV. This excellent resolution means that the photopeak can be placed in a narrow portion (about 1 keV) of the background energy spectrum. Consequences of this feature are: (1) the subject background count rate for a given photopeak is low (between 0.025 and 0.035 counts/min per cm/sup 2/ detector surface area for a 1-keV band in the range of 15 to 100 keV); (2) the subject background can be well estimated from counts in the energy spectrum a few keV above the photopeak of interest; (3) baseline resolution can be obtained for photons separated by as little as 1.5 keV in energy; and (4) identification of unknown or unexpected radionuclides can be accomplished with good accuracy. Applications and capabilities of the system are discussed. The current application is for the measurement of plutonium via the measurement of the 59.54-keV gamma from /sup 241/Am. The measurement of L x-rays from the decay of plutonium is also discussed.

• Research Organization: Atomics International Div., Golden, Colo. (USA). Rocky Flats Plant
• DOE Contract Number: EY-76-C-04-3533
• OSTI ID: 6787291
• Report Number(s): RFP-2777; CONF-780612-5
• Country of Publication: United States
• Language: English

Related Subjects

440101 -- Radiation Instrumentation-- General Detectors or Monitors & Radiometric Instruments
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
560171* -- Radiation Effects-- Nuclide Kinetics & Toxicology-- Man-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
ALPHA DECAY RADIOISOTOPES
AMERICIUM 241
AMERICIUM ISOTOPES
BODY
CONTAMINATION
ENERGY RANGE
ENERGY RESOLUTION
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
GE SEMICONDUCTOR DETECTORS
HEAVY NUCLEI
HIGH-PURITY GE DETECTORS
INHALATION
INTAKE
ISOTOPES
KEV RANGE
KEV RANGE 10-100
KEV RANGE 100-1000
LUNGS
MEASURING INSTRUMENTS
MONITORING
NUCLEI
ODD-EVEN NUCLEI
ORGANS
PERSONNEL
PERSONNEL MONITORING
PLUTONIUM 239
PLUTONIUM 240
PLUTONIUM ISOTOPES
RADIATION DETECTORS
RADIATION MONITORING
RADIOISOTOPES
RESOLUTION
RESPIRATORY SYSTEM
SEMICONDUCTOR DETECTORS
YEARS LIVING RADIOISOTOPES