Photo sources

  • This type of source uses the (g, n) reaction.
  • An advantage of this type of source is that monoenergetic neutrons may be obtained.
    9Be + g 8Be + n Q = -1.6 MeV
    d + g p + n Q = -2.23 MeV

  • The main disadvantage is the unavoidable g ray background.  They are also bulkier and give smaller yields than (a, n) sources.

See also: Radioactive sources