AbstractThe relative neutron capture and fission cross section in the neutron energy range 0.02 to 1.0 eV have been simultaneously measured. The data are normalized by means of the previously reported total cross section. The technique used consisted of passing a pulsed neutron beam through a233U fission chamber placed at the center of a large liquid scintillator. The prompt-neutron capture gamma rays were detected only in the liquid scintillator whereas a fission event was characterized by coincident signals from the liquid scintillator and fission chamber. This technique provides a new method of obtaining eta in this neutron energy range which is not subject to the same type of errors as are associated with a direct measurement. Comparisons with previously published data are given.