Experimental determination of the yield of “scission” neutrons from the spontaneous fission of 252Cf

Angular and energy distributions of prompt neutrons from the spontaneous fission of 252 Cf have been measured. The yield of “scission” neutrons has been estimated by comparing the measured distributions with calculations within the model of emission of neutrons from completely accelerated fragments. It has been shown that the best description of measured angular and energy distributions of fission neutrons is achieved under the assumption that neutrons with a higher (about 6–8%) probability are emitted along the fission axis in the center-of-mass system of fission fragments.