Deducing the 237U(n,f) cross section using the surrogate ratio method

We have deduced the cross section for 237U(n,f) over an equivalent neutron energy range from 0 to 20 MeV using the surrogate ratio method. A 55 MeV 4He beam from the 88 inch cyclotron at Lawrence Berkeley National Laboratory was used to induce fission in the following reactions: 238U(α,α'f) and 236U(α,α'f). The 238U reaction was a surrogate for 237U(n,f), and the 236U reaction was used as a surrogate for 235U(n,f). Scattered α particles were detected in a fully depleted segmented silicon telescope array over an angle range of 35 deg. to 60 deg. with respect to the beam axis. The fission fragments were detected in a third independent silicon detector located at backward angles between 106 deg. and 131 deg