Systematics of isomeric cross section ratio for neutron-induced reactions

Based on the statistical theory and available measured isomeric cross secti on ratio, a systematic formula of the isomeric cross section ratio with one parameter for neutron induced reactions was developed. This formula is app licable for the mass region 44 less than or equal toA less than or equal to 197, spin region of isomeric and ground states 0 less than or equal toJ(m) less than or equal to 12: and 0.5 less than or equal toJ(g)less than or equ al to8 of the residual nucleus, respectively. Fair agreement was obtained b etween the systematics predictions and measurements. Within the range of nu clides and spins the systematics predictions can provide useful isomeric cr oss section ratio information where experimental data are of large discrepa ncy or where experimental data are not available.