Experimental investigation of the form of the energy distribution of neutrons in the spontaneous fission of252Cf

In the last fewyears certain progress has been made in the investigation of the spectrum of instantaneous neutrons from the 25=Cffission, with the =52Cf being an international standard [1-5]. However, the accuracy with which the spectrum is known to date does not satisfy the requirements which must be met by ~ such a standard. Therefore, new precision meaurements must be made in the entire energy range (particularly above 5 MeV) in which the experimental data differ substantially.