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Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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New coolants, new fuels: A new generation of university reactors
Here’s an easy way to make aging U.S. power reactors look relatively youthful: Compare them (average age: 43) with the nation’s university research reactors. The 25 operating today have been licensed for an average of about 58 years.
P. I. Johansson, B. Holmqvist
Nuclear Science and Engineering | Volume 62 | Number 4 | April 1977 | Pages 695-708
Technical Paper | doi.org/10.13182/NSE77-A15210
Articles are hosted by Taylor and Francis Online.
The prompt fission neutron spectrum emitted by a sample of 235U irradiated with 0.53-MeV neutrons has been measured in the 0.6- to 15-MeV energy range by using time-of-flight (TOF) techniques. In the present work, a major effort was made to obtain an accurate experimental determination of the energy response and efficiency function of the neutron detector over the entire neutron energy range of interest. For this purpose, the TOF spectrometer was calibrated with respect to energy in the 0.5- to 21-MeV range by observing neutron groups from various nuclear reactions. The energy dependence of the neutron detector efficiency was determined by observing the angular distributions of the H(n,n)H process in the 1- to 15-MeV energy range. The overlapping 0.6- to 3-MeV energy range was covered by the T(p,n)3He reaction. The result of the fission neutron spectrum measurements has been used to find a suitable distribution function describing the data in the entire energy interval. The best description was obtained with the distribution N1(E) exp(–1.02E)sinh(2.32E)1/2.
