Re[2]: I-125, 131 sources

[FRAMEP@ORAU.GOV]

          It is acutely embarassing that I can't provide more info
          about mock iodine than what follows. The stuff was first
          developed by the late great Marshall Brucer when he worked
          at ORAU in the 1950s. The historical collection here
          contains one of his primary mock iodine standard sets
          assayed in 1959.  As Albert surmized, the additional
          component is Cs-137.  The set says that the ratio of Ba-133
          to Cs-137 was 12 to 1.  An Amersham catalog I have lists
          "simulated iodine" and says it contains Cs and Ba but
          doesn't give the ratios.  I'm sure they can provide the
          data.  Interestingly, the catalog warns that the mock source
          emits a bunch of low energy photons that could lead to
          summation losses  - something that could be especially
          significant with a well counter.  They suggest a cadmium
          filter be used when counting the mock source to cut out its
          low energy component.
             ANSI 42.13 might say something about this but I don't
          have a copy and can't be sure.

          Salutations and regards

          Paul

          HP trivia: Otto Hahn died on this date in 1968
          and last Tuesday, the 26th, was the 99th wedding aniversary
          of Marie and Pierre Curie