Lawrence Berkeley National Laboratory

The internal surrogate ratio method allows for the determination of an unknown cross section, such as (n,y), relative to a better-known cross section, such as (n,f), by measuring the relative exitchannel probabilities of a surrogate reaction that proceeds through the same compound nucleus. The validity of the internal surrogate ratio method is tested by comparing the relative gamma and fission exit-channel probabilities of a 236U* compound nucleus, formed in the 235U(d,p) reaction, to the known 235U(n,y) and (n,f) cross sections. A model-independent method for measuring the gamma-channel yield is presented and used. PACS numbers: 24.87.+y, 24.75.+i, 24.50.+g, 25.85.Ge