Neutron Yields from Uranium Isotopes in Uranium Hexafluoride

Neutron yields in UF6 arising from the 19F(α, n)22Na reaction and spontaneous fission of 238U are reported. Passive neutron counting in nearly 4π geometry was used to measure the absolute yields from eight small UF6 samples of varying isotopic composition. The specific yields for 234U and 238U are in excellent agreement with values calculated from thick target excitation functions for fluorine. The values of the specific yield from the four uranium isotopes are also in reasonable agreement with recent measurements utilizing a similar technique.