FAST PILE-NEUTRON SPECTRA AFTER PASSAGE THROUGH GRAPHITE, LEAD, AND IRON

Journal Article · Wed Jan 01 04:00:00 EST 1964 · At. Energ. (USSR)

OSTI ID:4028777

Veselkin, A P; Egorov, Yu A; Orlov, Yu V; Pankrat'ev, Yu V

Following up previous work by V. N. Avaev et al. (Atomnaya Energ. 15: 20(1963)), a fast-neutron scintillation spectrometer, provided with a H- containing sensor, was used for the determination of the fast-neutron spectrum of a water-cooled, water-moderated reactor within the 0.7- to 1.1-Mev range, after allowing the neutrons to pass through varying thicknesses of graphite, Pb, and Fe. Tests with a Co/sup 60/ source indicated that the spectrometer used does not record gamma radiation with a maximum energy of 1.33 Mev, if its dose rate does not exceed 15 microcurie/ sec; in that case, the energy threshold of the instrument was 0.4 Mev. Using 22.5- and 45-cm thick graphite layers, the calculated and measured spectra agreed with each other within the limits of the experimental error. At E/sub n/ < 4.5 Mev, the measured neutron fluxes exceeded the calculated ones by a factor of 2 to 3; the divergence was probably due to the geometry used in the experiments. Using layers thicker than 45 cm, maxima and minima were noted in the 3- to 7-Mev range; they were caused by the irregularities in the energy dependence of the total interaction cross section of the neutrons with the nuclei. From the spectral distribution, the fast-neutron attenuation in the various energy ranges was calculated together with the stripping cross section the the relaxation length. The data obtained may be used for reactor shielding calculations. (TTT)

• Research Organization: Originating Research Org. not identified
• NSA Number: NSA-18-019261
• OSTI ID: 4028777
• Journal Information: At. Energ. (USSR), Journal Name: At. Energ. (USSR) Vol. Vol: 16
• Country of Publication: Country unknown/Code not available
• Language: Russian

Related Subjects

ATTENUATION
COBALT 60
CONFIGURATION
CROSS SECTIONS
DIFFUSION LENGTH
ENERGY
ENERGY RANGE
ERRORS
FAST NEUTRONS
GAMMA RADIATION
GAMMA SOURCES
GRAPHITE
HYDROGEN
INTERACTIONS
IRON
LEAD
LOSSES
MEASURED VALUES
NEUTRON DETECTION
NEUTRON FLUX
NEUTRON SPECTROMETERS
NUCLEAR REACTIONS
NUCLEI
NUMERICALS
PHYSICS
RADIATION DOSES
REACTORS
RELAXATION
SCINTILLATION COUNTERS
SHIELDING
SPECTRA
STRIPPING
TESTING
THICKNESS
WATER COOLANT
WATER MODERATOR