Measuring fast-neutron flux by analysis of barium-140 from uranium-238 fission

Journal Article · Thu Jan 01 04:00:00 EST 1981 · Annu. Book ASTM Stand.; (United States)

OSTI ID:5609841

The method describes two procedures for the measurement of fast-neutron flux densities by determining the amount of the fission product /sup 140/Ba produced by the threshold reaction /sup 238/U(n,f)f.p. The reaction produces many fission products, among which is /sup 140/Ba, having a half-life of 12.79 days. Competing activity from other fission products requires that a chemical separation be employed or that the /sup 140/Ba activity be determined indirectly by counting the daughter product /sup 140/La. The method describes both procedures: (1) the nondestructive determination of /sup 140/Ba by the direct counting of /sup 140/La several days after the /sup 238/U irradiation; and (2) the chemical separation of /sup 140/Ba and the subsequent counting of /sup 140/Ba or its daughter /sup 140/La. With suitable techniques, fission neutron flux densities can be measured in the range from 10/sup 7/ n (neutrons).cm/sup -2/.s/sup -1/ to approximately 10/sup 15/ n.cm/sup -2/.s/sup -1/. The method includes a discussion of significance, apparatus, reagents and materials, preparation and standardization of barium carrier, procedure for nondestructive analysis, procedure for radiochemical analysis, calculations, precision, and accuracy. (JMT)

• OSTI ID: 5609841
• Journal Information: Annu. Book ASTM Stand.; (United States), Journal Name: Annu. Book ASTM Stand.; (United States) Vol. 45; ISSN ABASC
• 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
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
ACTIVATION DETECTORS
ACTIVITY LEVELS
ALKALINE EARTH ISOTOPES
ALPHA DECAY RADIOISOTOPES
BARIUM 140
BARIUM ISOTOPES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CALCULATION METHODS
CHEMICAL ANALYSIS
DAYS LIVING RADIOISOTOPES
EVEN-EVEN NUCLEI
FISSION PRODUCTS
GAMMA SPECTROMETERS
HALF-LIFE
HEAVY NUCLEI
INDUSTRY
INTERMEDIATE MASS NUCLEI
ISOTOPES
LANTHANUM 140
LANTHANUM ISOTOPES
MATERIALS
MEASURING INSTRUMENTS
MEASURING METHODS
NEUTRON DETECTORS
NEUTRON FLUX
NONDESTRUCTIVE ANALYSIS
NUCLEAR INDUSTRY
NUCLEI
ODD-ODD NUCLEI
QUANTITATIVE CHEMICAL ANALYSIS
RADIATION DETECTORS
RADIATION FLUX
RADIOACTIVE MATERIALS
RADIOCHEMICAL ANALYSIS
RADIOISOTOPES
RARE EARTH ISOTOPES
RARE EARTH NUCLEI
REAGENTS
SEPARATION PROCESSES
SPECTROMETERS
STANDARDIZATION
STANDARDS
URANIUM 238
URANIUM ISOTOPES
YEARS LIVING RADIOISOTOPES