Gremyachkin D.E., Piksaikin V.M., Egorov A.S., Mitrofanov V.F., Samylin B.F., Mitrofanov K.V.
A.I. Leypunsky Institute for Physics and Power Engineering, Obninsk, Russia
In the present work, measurements of the relative abundances of delayed neutrons and half-lives of their precursors in the neutron induced fission of 238U in the energy range from 14 to 18 MeV, have been done. Measurements have been done using 4π-neutron detector consisted of 30 boron counters SNM-11 type embedded in polyethylene moderator. The data obtained experimentally have been processed taking into account the effect of detector blocking (of the detector) and effect of additional neutron source. Values of energy residual after neutrons emission have been calculated by the means of equation of the energy balance. Energy dependence of the average half-life of delayed neutron precursors emitted by the fission products on the final stage of the fission process of heavy nuclei and systematics of the average half-life of delayed neutron precursors allowed us to calculate average half-lives of delayed neutron precursors for the fission of compound nucleus arising in the process of emissive fission. Using the data obtained in the present work and data from different works the analysis of the chance structure of the emissive fission cross section of the 238U have been done in the terms of average half-life of delayed neutron precursors.
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