Neutron activation resonance integrals of 74Se, 78Se, 80Se, 81Br, 127I, 130Te, 138Ba, 140Ce, and 142Ce

A lithium-drift germanium γ-ray spectrometer has been used to make accurate intercomparisons of the ratio of resonance-integral to thermal-activation cross section by measuring cadmium ratios or relative activation rates in two different neutron spectra. The standard, gold, or secondary standard, indium, was mixed uniformly in the samples and the activities resolved with the spectrometer. Expressed as Westcott s0 values, the results relative to s0 = 17.7 for gold were as follows: 74Se = 10.3 ± 0.1, 78Se = 12.3 ± 0.3, 80Se = 2.65 ± 0.02, 81Br = 24.3 ± 0.5, 127I = 27.8 ± 0.5, 130Te = 2.10 ± 0.07, 138Ba = 0.649 ± 0.004, 140Ce = 0.476 ± 0.003, 142Ce = 0.865 ± 0.005.