Correlations of neutron multiplicity and γ -ray multiplicity with fragment mass and total kinetic energy in spontaneous fission of Cf 252
The dependence of correlations of neutron multiplicity ν and γ-ray multiplicity M γ in spontaneous fission of 252 Cf on fragment mass A* and total kinetic energy (TKE) have been investigated by employing the ratio of M γ /ν and the form of M γ (ν). We show for the first time that M γ and ν have a complex correlation for heavy fragment masses, while there is a positive dependence of Mγ for light fragment masses and for near-symmetric mass splits. The ratio M γ /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 M γ (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.