September 10, 1952

At the time our instrumentation plans were started a
search of manufacturer's catalogues did not reveal any
suitable ioniztion chamber as being commercially available.
Drawings for the B10 chamber designed at the Oak Ridge
National Laboratories were obtained. The drawings were
studied carefully by Dr. Waltner and myself and performance
characteristics were discussed with P. R. Bell and W H Jordon.
It appeared as if this chamber was the most suitable one for
us to use. Three aspects of the chamber present special
problems. 1. The metal parts are of magnesium and special
machining techniques are necessary to avoid the fire hazard.
2. The technique of applying the Boron 10 coating requires
the induction heating of the graphite parts in an inert
atmosphere. 3. The quartz insulation must be fabricated by
the General Electric Co. Also it is difficult to machine thhe
graphite parts in such a fashion that pits are avoided.
The construction of two chambers was started in the machine
shop of Engineering Research. It was recently learned that
Radiation Counters Laboratory is making some of these
chambers for the A. E. C. and that they will make two for
us at 1295 dollars each. In view of the above mentioned
problems, it is believed that we would do well to purchase
two of these ion chambers from R C L. This will ensure us
having two operating chambers on hand (delivery date quoted
was in October for an order placed in August) and thus avoid
a likely time delay in operating the reactor due to difficulties
arising in our construction of the chambers. It is therefore
recommended that two of the chambers be obtained as soon as
possible from R C L.