The average number of prompt neutrons [formula omitted], from neutron induced fission of 235U between 0.2 and 1.4 MeV

Abstract

For the clarification of existing discrepancies in the energy dependence of v ̄ p for 235U an experiment was performed which was based on a method independent of current techniques. A considerable reduction of background and correction problems was achieved by renouncing on an absolute measurement. Thus the resulting systematic uncertainty was 0·6%. In the energy range between 0·2 and 1·4 MeV the shape of v ̄ p was measured at 22 points in steps of 50 keV with an average energy resolution of 3·3%. Repetition of several runs with modified experimental conditions ensured the consistent reproduction of the results. It was found that v ̄ p of 235U shows distinct deviations of up to 2% from a linear energy dependence.