In this paper

we report the experiment based on time correlation coincidence to measure uranium enrichment.With the time tagged by a 252Cf spontaneous fission neutron source

measurements were done on uranium metal castings of similar quantity(about 8 kg) and shape(hemispherical shell) but in different enrichments.The characteristic of time correlation coincidence counts between the source and detector were obtained.By analyzing these counts

many groups of special parameters can be obtained to characterize the fission signal.These parameters are sensitive to changes in uranium enrichment

with a sensitivity coefficient of 19.4%.Therefore

uranium metal castings of different enrichments can be identified for the purpose of nuclear warhead verification.