The mass-yield curve for fission of natural uranium by 14-MeV neutrons

Abstract

Relative yields for the fission of natural uranium (effectively 238U fission) by 14-MeV neutrons have been measured for mass numbers 89, 91, 99, 111, 115, 140, 143, 144, 147, 153, and 156, and the general shape of the mass-yield curve is given. The peak-to-trough ratio is 9·1 ; the average number of prompt neutrons emitted per fission is found to be (4 ± 0·5); and a value for the absolute fission yield of 99Mo is found to be (5·58 ± 0·56) per cent. The light peak has moved 3–4 units towards the heavy peak when compared with the 14-MeV fission of 235U.