February, 1952

1. When in Oak Ridge, I asked Walter Jordan about supplies for spur gear
assemblies. He referred me to Tom Cole, who has designed the control
system for the "swimming pool" reactor. He had used an available NEPA
product, which was much too bulky for the job. He recommends spur rather
than worm gears because of friction, and that we should get standard
gears from the Boston Gear Works and design the assembly to our own
needs

2. Discussed artificial neutron sources with R. Charpie of Y-12. The
Isotope SB124 is a high energy gamma emitter, which gives neutrons by
a ([gamma],n) reaction on Be. Its virtus is that it gives a high intensity,
the anatomony being of short (60 da) half life.

Two References on the properties of sources should be obtained:

• Neutrons from Alpha Emitters, H. L. Anderson, Report #3,
  Nuclear Science Series, National Research Council (2101
  Constitution Ave., Washington, D. C.)
•  
• Photo Neutron Sources, A. Watlenberg, Report #6, same series.

Before stating positively that an Sb source would be activated in our
reactor to such a degree that its life is extended, I should like to study
some of the data on yields in these reports. Continous neutron irradiation
might be needed, actually.