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|"Century of the Atom." 1971.
Produced by the U.S. Atomic Energy Commission.
Producing a Chain Reaction (1:43)
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Herbert Anderson: Fermi told me at the time that the quickest way to the chain reaction and all its
consequences was to make a chain reaction and that could probably be done first and
most easily by the techniques most familiar to him using natural uranium.
And so we launched on a career of trying first of all to see what neutrons were emitted,
and in what number. And a great deal of emphasis was placed on the quantitative aspects
of the subject. The paper "The production of neutrons in uranium bombarded by neutrons"
by Anderson, Fermi and Hanstein, was submitted to the Physical Review one month after that, March 16, 1939, and then appeared in the April 15th issue.
And this showed that indeed neutrons were emitted and in fairly copious numbers, experiments
were a little bit on the rough side, but one could conclude from that experiment that
one and a half neutrons were emitted from uranium for each thermal neutron that was
absorbed by uranium, and that was a very important number, and not really very far
from what is now known to be the value of that number, about 1.33.
Experiments are also being done -- in fact they always seem to be about a week or
so ahead of us -- by Joliot, Halban and Kowarski, working in Paris under very difficult
conditions, and at the same time, and going on in the same laboratory at Columbia,
Szilard had gotten together with Zinn, and they also carried out an experiment demonstrating
the emission of fast neutrons when uranium absorbed a thermal neutron.
ClipCreator: Herbert Anderson
Associated: Enrico Fermi, Henry B. Hanstein, Hans von Halban, Frédéric Joliot-Curie, Lew Kowarski,
Leo Szilard, W.H. Zinn
Clip ID: energy1167-chainreaction
Full WorkCreator: Atomic Energy Commission
Associated: Otto Hahn, Otto Frisch, Herbert Anderson, Glenn T. Seaborg, Chet Huntley
Copyright: More Information