CP-1 and CP-2

Following the successful chain reaction experiment on December 2, 1942, Met Lab scientists continued further experiments on the CP-1 reactor. At the end of February 1943, CP-1 was dismantled so that the materials forming the reactor could be moved to Site A, a secure location in Cook County’s Argonne Forest Preserve twenty miles southwest of Chicago. There the reactor was reconstructed in a more cubical form, with a larger quantity of uranium and increased concrete shielding against radiation.

Renamed CP-2, the new reactor began operation in March 1943 and became the focus of important experimental work by Enrico Fermi, Herbert Anderson, Leona Woods Marshall, and other Met Lab scientists who commuted from Hyde Park to Site A on a regular basis. On the University of Chicago campus, the space beneath West Stand of Stagg Field was reconfigured and transformed into a modern laboratory for Met Lab work.

Herbert L. Anderson, CP-1 notebook, 1942-1943
Herbert L. Anderson, CP-1 notebook, 1942-1943

Herbert L. Anderson Papers, The Hanna Holborn Gray Special Collections Research Center, University of Chicago
Anderson's handwritten notes about the chain reactions in CP-1 and CP-2 on the left page, and a hand-drawn diagram of a cross-section of CP-2 on the right page.
Herbert L. Anderson, CP-1 and CP-2 operations notebook, 1943

Herbert L. Anderson Papers, The Hanna Holborn Gray Special Collections Research Center, University of Chicago
Anderson's handwritten notes dated February 7, 1943 and titled "Standardization of CP1"
Herbert L. Anderson, CP-1 and CP-2 operations notebook, 1943
Anderson's handwritten notes titled "Standardization of CP2," including sections called "Characteristics of CP2" and "Intensity Calibrations"
Herbert L. Anderson, CP-1 and CP-2 operations notebook, 1943

Herbert L. Anderson Papers, The Hanna Holborn Gray Special Collections Research Center, University of Chicago
The blue paper motor vehicle operator's permit issued to Fermi, with his signature verifying him as the operator
Enrico Fermi, Metallurgical Laboratory driver's permit, 1946

Enrico Fermi Collection, The Hanna Holborn Gray Special Collections Research Center, University of Chicago
The official date of issue for Fermi's permit
Enrico Fermi, Metallurgical Laboratory driver's permit, 1946

Enrico Fermi Collection, The Hanna Holborn Gray Special Collections Research Center, University of Chicago
Enrico Fermi, "The Development of the First Chain Reacting Pile," Proceedings of the American Philosophical Society, vol. 90, no. 1, January 1946

Enrico Fermi Collection, The Hanna Holborn Gray Special Collections Research Center, University of Chicago
Enrico Fermi, "The Development of the First Chain Reacting Pile," Proceedings of the American Philosophical Society, vol. 90, no. 1, January 1946

Enrico Fermi Collection, The Hanna Holborn Gray Special Collections Research Center, University of Chicago
Enrico Fermi, "The Development of the First Chain Reacting Pile," Proceedings of the American Philosophical Society, vol. 90, no. 1, January 1946
Enrico Fermi, "The Development of the First Chain Reacting Pile," Proceedings of the American Philosophical Society, vol. 90, no. 1, January 1946

Enrico Fermi Collection, The Hanna Holborn Gray Special Collections Research Center, University of Chicago
Herbert L. Anderson, Enrico Fermi, and Leona Marshall, "Production of Low Energy Neutrons by Filtering through Graphite," The Physical Review, vol. 70, December 1946

Enrico Fermi Collection, The Hanna Holborn Gray Special Collections Research Center, University of Chicago
Herbert L. Anderson, Enrico Fermi, and Leona Marshall, "Production of Low Energy Neutrons by Filtering through Graphite," The Physical Review, vol. 70, December 1946

Enrico Fermi Collection, The Hanna Holborn Gray Special Collections Research Center, University of Chicago
Instructions for data collection on the left page and original "Secret" stamps, and later "Classification cancelled" on the right page
Samuel K. Allison, Director, Metallurgical Laboratory, data collection instructions, undated

Ralph Livingston Papers 2018-056, The Hanna Holborn Gray Special Collections Research Center, University of Chicago
The simple brown leather cover of Ralph Livingston's Metallurgical Laboratory notebook
Ralph Livingston, Metallurgical Laboratory notebook, 1944-1945

Ralph Livingston Papers 2018-056, The Hanna Holborn Gray Special Collections Research Center, University of Chicago
The title page of "Elementary Theory of the Pile," inclduing the date of declassification
Elementary Theory of the Pile, 1946

John A. Simpson Papers, The Hanna Holborn Gray Special Collections Research Center, University of Chicago
The first page of "Elementary Theory of the Pile"
Elementary Theory of the Pile, 1946