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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.
H. H. Nichols
Nuclear Technology | Volume 9 | Number 1 | July 1970 | Pages 112-119
Instrument | Symposium on Theoretical Models for Predicting In-Reactor Performance of Fuel and Cladding Material | doi.org/10.13182/NT70-A28733
Articles are hosted by Taylor and Francis Online.
The integral gamma-ray counting efficiency was measured for six CdTe detectors using gammas from 57Co, 85Kr, 137Cs, and 60Co. Changes in efficiency were measured as a function of temperature (-50 to 66°C), detector bias (50 to 100 V), pulse clipping time (0.25 to 1.6 µSec), and energy threshold setting (25, 50, 75, and 100 keV). The change is mainly due to trapping and detrapping of charge carriers. For a clipping time of 1 µ sec, changes in efficiency tiS high as 300% were observed over the temperature range -50 to 66°C. This change in efficiency was reduced to <10% by using only the fast component of the pulses generated. Total gamma-ray efficiency approaching the theoretical limit was measured at 23°C. Presently, CdTe detectors are not intended for use as spectrometers, but are intended to be used as gamma-ray counters over a wide temperature range.
