Boron contamination of graphite also slowed the Manhattan Project:
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Fermi writes that "The results of this experiment was [sic] somewhat discouraging" presumably because of the absorption of neutrons by some unknown impurity. So, in December 1940 Fermi and Szilard met with Herbert G. MacPherson and V. C. Hamister at National Carbon to discuss the possible existence of impurities in graphite. During this conversation it became clear that minute quantities of boron impurities were the source of the problem.
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Awesome article and interesting to see Heisenberg get it wrong. It really was a perfect situation for the US because we could get all the radioactive material with little issue.
A clean reminder that logistics is everything.
Also cool that the author is married to Sean Carroll.
" Fermi writes that "The results of this experiment was [sic] somewhat discouraging" presumably because of the absorption of neutrons by some unknown impurity. So, in December 1940 Fermi and Szilard met with Herbert G. MacPherson and V. C. Hamister at National Carbon to discuss the possible existence of impurities in graphite. During this conversation it became clear that minute quantities of boron impurities were the source of the problem. "
https://en.wikipedia.org/wiki/Nuclear_graphite
A clean reminder that logistics is everything.
Also cool that the author is married to Sean Carroll.