A new method of absolute neutron flux determination using an associated gamma-ray technique

https://doi.org/10.1016/0029-554X(76)90042-2Get rights and content

Abstract

The 7Li(p,n1γ)7Be reaction is developed as a primary neutron standard for the determination of absolute neutron flux and neutron detector efficienty over a neutron energy range 0.350 ≤En≤2.8 MeV. A new associated γ-ray method is used, in conjunction with a neutron time-of-flight spectrometer, whose essential feature is that the associated γ-ray to neutron ratio is known. For the 7Li(p,n1γ)7Be reaction the ratio of the 431 keV γ-rays to n1 neutrons is unity. It simplifies the method that the 431 keV γ-rays associated with the n1 neutrons have an isotropic angular distribution. In this case, an accurate measurement of the 431 keV γ-rays emitted at any angle determines the total number of n1 neutrons emitted independent of the 7Li(p,n1)7Be cross section, Li target thickness, and beam current. After the n1 angular distributions are determined as a function of proton energy, the 7Li(p,n1γ)7Be reaction can be used to determine the absolute n1 neutron flux at any angle by measuring the 431 keV γ-ray production, for this purpose, twelve n1 neutron angular distributions have been measured between 3.1≲Ep≲4.9 MeV.

References (14)

  • J.C. Hopkins et al.

    Nucl. Data

    (1971)
  • A.B. Smith et al.

    Phys. Rev. C

    (1970)
  • A. Langsdorf et al.

    Phys. Rev.

    (1957)
    R.O. Lane et al.

    Phys. Rev.

    (1969)
  • J.D. Brandenberger et al.

    Bull. Am. Phys. Soc.

    (1974)
  • F.D. McDaniel et al.

    Phys. Rev. C

    (1974)
    D.E. Velkley et al.

    Phys. Rev. C

    (1974)
  • J. E. Brolley, Jr., and J. L. Fowler, in Fast neutron physics (eds. J. P. Marion and J. L. Fowler; par I, p....
  • J. H. Gibbons and H.W. Newson, (eds.J.P. Marion and J.L. Fowler; par I, p....S.A. Elbakr et al.

    Nucl. Instr. and Meth.

    (1972)
    S.T. Thornton

    Nucl. Phys.

    (1969)
There are more references available in the full text version of this article.

Cited by (1)

Present address: Department of Physics, University of Pittsburgh, Pittsburgh, Pennsylvania, U.S.A.

Nuclear Information Research Associate, supported by the National Science Foundation through the National Research Council - National Academy of Science Committee on Nuclear Science. Present Address: Brookhaven National Laboratory, Upton, New York, U.S.A.

+

Present address: Department of Physics, North Texas State University, Denton, Texas, U.S.A.

View full text