Measurement of a two-neutron correlation function for the 252 Cf fission

For the 252 Cf fission, the two-neutron correlation function is measured. The energy of each detected neutron is determined by the time-of-flight method. The geometry of the detectors made it possible to separate neutrons emitted by light and heavy fragments. Variances of prompt light-fragment neutron multiplicity distribution σl2 = 1.09 ± 0.05 and heavy-fragment neutron multiplicity distribution σh2 = 1.03 ± 0.04 are determined. The coefficient ρlh of correlation between the numbers of the prompt neutrons from the light fragment and from the heavy fragment is obtained to be ρlh = -0.26 ± 0.02. In case of detection of two neutrons from one fragment, the dependence of the correlation functions on the neutron energy differs from the similar dependence in case of detection of two neutrons from complementary fragments. 10 refs