Abstract
Two methods are compared for determining the subcriticality in neutron-multiplying media: the standard californium chamber method and the modified α-Rossi method, which differs from the traditional approach in that the α-Rossi time distribution is corrected for the spontaneous fission source. It is shown that one can derive 1-k from the measured α-Rossi distribution if the intensity is known. The ranges where the two methods can be used are substantially different. When there are spontaneous fissions, the statistical fluctuations do not allow one to determine k<0.9 reliably in the first method, whereas the second one can be used also for k<0.5. Also, if {ie100-1} is determined from the californium chamber method, then the α-Rossi method enables one to determine k, which is unrelated to {ie100-2}, the effective fraction of delayed neutrons.
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Joint Atomic Energy Institute.
Translated from Atomnaya Énergiya, Vol. 86, No. 2, pp. 99–103, February, 1999.
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Dulin, V.A., Dulin, V.V. Measuring subcritical states in neutron-multiplying media. At Energy 86, 100–104 (1999). https://doi.org/10.1007/BF02673529
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DOI: https://doi.org/10.1007/BF02673529