On prompt fission neutron spectrum in spontaneous fission of 252Cf

• We use simple analytical approach for PFNS in the laboratory system.
• We compare our calculations with the observed PFNS in spontaneous fission of 252Cf.
• LCL spectrum gives better representation of observed spectrum comparing with Watt spectrum.
• A significant portion of scission neutrons can be described with our calculations.
• Beside the Watt spectrum, LCL spectrum may also be used for representation of PFNS of 252Cf252Cf (sf).

In this work we use simple representations of prompt fission neutron spectrum in both the center of mass system of fission fragments and the laboratory system which takes into account the multiple neutron emission from fission fragments. The laboratory spectra are compared with the observed spectrum of prompt fission neutrons in spontaneous fission of 252Cf252Cf. These forms of spectra, in addition to Watt spectrum, may be used for representation of observed prompt neutron spectrum of 252Cf252Cf spontaneous fission. The question on existence and quantity of scission neutrons is also discussed.