Distribution in Energy of the Neutrons from the Interaction of 14-Mev Neutrons with Some Elements

Graves, E. R.; Rosen, Louis

doi:10.1103/physrev.89.343

Cited by 115 publications

(20 citation statements)

References 14 publications

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“…Therefore, both formulas can be used from the practical point of view to obtain the energy spectra with their appropriate values for the parameter. Equation ( 3 ) has been used frequently in the past.…”

Section: Figmentioning

confidence: 99%

Inelastic Scattering of 14MeV Neutrons by Medium Weight Nuclei

Fujita

Sonoda

Katase

et al. 1972

Journal of Nuclear Science and Technology

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Continuous spectra of neutrons inelastically scattered from Ti; V, Cr. Mn, Fe, Co, Ni, CU, Zn, Ge and As have been measured at an incident energy of 14MeV with good statistics. Time-of-flight technique was used. In the analyses there were used three sets of inverse-reaction cross section Of : (1) calculated with Perey-Buck potential, (2) with Bjorklund-Fernbach potential and (3) cross section assumed to be constant. The inverse-reaction cross section does not affect appreciably the values of nuclear temperature or nuclear level density parameter for these nuclei except Ti, V and Cr. The nuclear temperature was found to be nearly constant in the mass number region of . The level density parameter as a function of m a s number follows the general trend suggested by Newton. Newton's coefficient is found to be 0.092, in agreement with values obtained in other experiments. The total inelastic scattering cross sections are derived. 301

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Section: Figmentioning

confidence: 99%

Inelastic Scattering of 14MeV Neutrons by Medium Weight Nuclei

Fujita

Sonoda

Katase

et al. 1972

Journal of Nuclear Science and Technology

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“…Figure 3 theoretically and are experimentally verified, but there is no direct cosmic-ray information about the higher-energy neutron source spectrum. Neutron spectra have been measured by Graves and Rosen [1953], using 14-Mev neutrons bombarding various elements, and by Gross [1956], using 190-Mev protons bombarding various elements. These authors find that below 3 or 4 Mev the neutrons are clearly identified as evaporation neutrons but that above 4 Mev the yield of neutrons is higher than expected from evaporation, and that the neutrons come off preferentially forward.…”

Section: Zoom a Neutron-diffusion Code [Stuart Canmentioning

confidence: 99%

Cosmic-ray neutron demography

Hess¹,

Canfield²,

Lingenfelter³

1961

J. Geophys. Res.

192

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The equilibrium spatial and energy distribution is calculated for neutrons made in the earth's atmosphere by cosmic rays. The neutron current leaking into space is found, and the density of neutron decays in the vicinity of the earth is computed for a future determination of importance as a source for the Van Allen belts. The spectrum and the leakage current below 10 Mev are determined from multigroup diffusion theory; the leakage above 10 Mev (<1 per cent of total) is approximated from geometrical arguments. An integrated source over each square centimeter of earth surface (at geomagnetic latitude 44°N) of 6.2 neutrons/sec (1.2 from ‘knock‐on’ processes above 10 Mev and 5.0 from evaporation processes below 10 Mev) gives an equilibrium spectrum in agreement with the ±25 per cent accuracy of measured values. This source corresponds to a global average of 4.6 neutrons/cm2/sec, of which 0.8 leaks into space, 2.9 form C14, and 0.9 is absorbed in other processes. Gravitationally trapped neutrons (<0.66 ev) amount to less than 1 per cent of the total leakage, but they contribute substantially to the decay density near the earth (e.g., 40 per cent of total decays at 1/2 earth radius).

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“…The energetic 14-MeV neutrons from the DTreaction would induce fast fission in the blanket. Subsequently, the neutrons could be captured in 238 U to form 239p u or in 6 Li to breed tritium. It was assumed that a proper arrangement of uranium and supporting structure would lead to a net multiplication of the incident neutrons.…”

Section: A Early Studiesmentioning

confidence: 99%

Fission-fusion systems: hybrid, symbiotic and augean

Lidsky

1975

Nucl. Fusion

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The achievement of controlled fusion will make available excess neutrons which can be used in various ways in combined fission-fusion power cycles. The various schemes are here classified as hybrid–in which heavy-element fission occurs in the fusion blanket; symbiotic–in which fissile material is bred in the absence of fission events; and augean–in which the neutron surplus is used to transmute fission reactor waste products. The earliest work in this field, unpublished and originally classified secret, is reviewed. Recent studies of hybrid systems based on subcritical thermal and sub-critical fast-fission blankets are described in detail. An analysis of symbiosis based on the Th-U fuel cycle is summarized. The conditions required for high-level waste transmutation are presented; Augean systems seem best suited to actinide waste burning. It is concluded that basic physics of various fission-fusion systems has been surveyed but the engineering and economic aspects of combined systems have been largely ignored. It remains to be shown whether fission-fusion systems will prove superior to alternative methods of accomplishing the same ends.

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Distribution in Energy of the Neutrons from the Interaction of 14-Mev Neutrons with Some Elements

Cited by 115 publications

References 14 publications

Inelastic Scattering of 14MeV Neutrons by Medium Weight Nuclei

Inelastic Scattering of 14MeV Neutrons by Medium Weight Nuclei

Cosmic-ray neutron demography

Fission-fusion systems: hybrid, symbiotic and augean

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