Analysis on delayed gamma spectra of products from uranium fission

Gamma spectra is the fingerprint of uranium materials in the arms control verification technology. To calculate and analyse delayed gamma spectra of fission products, we simplified the decay chain into basic state linear chain and excitation state linear chain. We deduced formulas of the changing rule for nuclide number before and after zero-time. We made the C program to calculate the delayed gamma ray spectra data, and carried on related experiments to check our theory. By analysing some nuclides' delayed gamma counts, the calculated results are well consistent with the experiment values.