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1942 to 1943: Early Manhattan Project

1942 to 1943: Early Manhattan Project

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Chicago Pile Argonne

1943 April 1

Fencing of the reservation completed -- Oak Ridge, TN is closed off to public access. Also, construction begins on plant for manufacturing gaseous diffusion barriers in Decatur, IL although no barrier materials of usable quality have yet been produced.

1943 April

By the end of the March planning sessions, the necessity of including ordnance development activity at Los Alamos was apparent. This greatly expanded the scope of work undertaken at the laboratory to engineering development, and eventually acting as prime contractor for weapon production, and manufacturer of key weapon components (including all nuclear components, and the implosion system).

1943 April

Hans Bethe is selected over Edward Teller to head the theoretical division. Teller is soon placed in charge of lower priority research on fusion weapons.

1943 April

A series of staff conferences among the roughly 100 scientific staff members are held at Los Alamos, NM. These include indoctrination lectures by Robert Serber (later published as The Los Alamos Primer) on April 5, 7, 9, 12, and 14; and meetings to plan the laboratory's work from April 15 through May 6. The laboratory's initial organization and leadership is worked out.

1943 April

At the beginning of the month the original building plan for Los Alamos, NM is 96% complete. It is already apparent that the original construction program is inadequate to meet needs.

1943 Mar 27

Richard Tolman writes J. Robert Oppenheimer about using explosives to collapse a shell into a critical mass. This is the earliest surviving reference to the idea of implosion (although this term was not used).

1943 Mar

The original construction program nears completion, and staff begins arriving at Los Alamos, NM to begin operations. From this point on the site grows non-stop through the end of the war.