Calculated Production of High-Energy Neutrons by 800-MeV Protons

    Published: Jan 1992

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    High Energy Transport Code (HETC) calculations were performed for 800-MeV protons incident on thin targets of various materials. The objective was to enhance the fraction of high-energy neutrons (E > 100 MeV) while maintaining a reasonable yield. A high yield of neutrons with energies greater than 100 MeV in companson to neutrons in the 5-MeV range can provide an experimental tool to study high-energy neutron radiation damage effects, activation, and other transmutation.

    It is shown that the preferential production of high-energy neutrons (E > 100 MeV) requires the use of light nuclei such as boron or beryllium. This is due to the fact that the intranuclear cascades in light nuclei are small enough so that very few nucleons share the energy of incoming particles. Furthermore, production of low-energy neutrons is suppressed since neutrons are mainly produced by direct particle-neutron interactions in the target material The paper also shows that fairly large variations in the target thickness do not affect the neutron spectrum for all targets studied This is because mean free paths of both incoming protons and outgoing neutrons are much larger than the target dimensions.

    In this work an effort is made only to maximize the high-energy neutron production in targets. However, to build a useful experimental facility for high-energy neutrons, one would need to calculate m detail the angular dependence of primary and secondary proton fluxes as well as scattered neutron fluxes from surrounding materials.


    neutrons, high energy, protons, spallation, tungsten, copper, nickel, boron, beryllium, High Energy Transport Code (HETC), irradiation, Monte Carlo

    Author Information:

    Hawari, AI
    Graduate student and associate professor, University of Missouri-Rolla, Materials Research Center, Rolla, MO

    Kumar, AS
    Graduate student and associate professor, University of Missouri-Rolla, Materials Research Center, Rolla, MO

    Greenwood, LR
    Technical group leader, Pacific Northwest Laboratory, Richland, WA

    Committee/Subcommittee: E10.08

    DOI: 10.1520/STP17857S

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