Correlations of neutron multiplicity and γ-ray multiplicity with fragment mass and total kinetic energy in spontaneous fission of 252Cf.

The dependence of correlations of neutron multiplicity ν and γ -ray multiplicity Mγ in spontaneous fission of 252Cf on fragment mass A* and total kinetic energy (TKE) have been investigated by employing the ratio of Mγ /ν and the form of Mγ (ν). We show for the first time that Mγ and ν have a complex correlation for heavy fragment masses, while there is a positive dependence ofMγ for light fragment masses and for near-symmetric mass splits. The ratio Mγ /ν exhibits strong shell effects for neutron magic number N = 50 and near doubly magic number shell closure at Z = 50 and N = 82. The γ -ray multiplicity Mγ has a maximum for TKE = 165–170 MeV. Above 170 MeV Mγ (TKE) is approximately linear, while it deviates significantly from a linear dependence at lower TKE. The correlation between the average neutron and γ -ray multiplicities can be partly reproduced by model calculations. [ABSTRACT FROM AUTHOR]