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Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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The Frisch-Peierls memorandum: A seminal document of nuclear history
The Manhattan Project is usually considered to have been initiated with Albert Einstein’s letter to President Franklin Roosevelt in October 1939. However, a lesser-known document that was just as impactful on wartime nuclear history was the so-called Frisch-Peierls memorandum. Prepared by two refugee physicists at the University of Birmingham in Britain in early 1940, this manuscript was the first technical description of nuclear weapons and their military, strategic, and ethical implications to reach high-level government officials on either side of the Atlantic. The memorandum triggered the initiation of the British wartime nuclear program, which later merged with the Manhattan Engineer District.
F. H. Helm
Nuclear Technology | Volume 2 | Number 4 | August 1966 | Pages 325-334
Technical Paper and Note | doi.org/10.13182/NT66-A27524
Articles are hosted by Taylor and Francis Online.
Gold spheres and foils were activated in a nonisotropic neutron flux in the center of boxes that were cadmium-lined on five sides and located in the graphite thermal column of the JUGGERNAUT reactor. The boxes were cubes, 5, 10, and 20 cm on a side and were either left void or filled with graphite. In the sphere measurements, an attempt was made to measure the angular flux distribution by scanning the spatial distribution of the activation over 1-cm-diam spheres. The results were compared to calculated values. Resolution curves were calculated for gold spheres of different diameters. The self shielding of 1-cm2 gold foils was measured for two different foil orientations and for foil thicknesses between 0.0013 and 0.05 cm. The self shielding was also calculated, approximating the angular flux distribution by polynomials and by step functions in the cosine of the angle of incidence. Finally, a qualitative method was developed to determine the angular flux distribution from the results of the self-shielding measurements with foils.
