The Effect of the J-pi Population Mismatch on the Surrogate Method

The surrogate method is an indirect means for determining neutron-induced reaction cross sections on unstable nuclei. This is accomplished by measuring the relevant decay probabilities of the composite nucleus of interest produced via a light-ion induced surrogate reaction using a stable target and beam. To properly characterize the surrogate method, the effect of differences in angular momentum populations between the surrogate light-ion and desired neutron-induced reactions must be determined. To this end, the following experiment was performed at the 88'' Cyclotron at Lawrence Berkeley National Laboratory: 235U(3He,af) and 238U(3He,af) as surrogates for 233U(n,f) and 236U(n,f), respectively. The extracted cross sections were compared to known values and the implication on the J-pi population mismatch will be discussed.