Excitation of high-spin nuclear isomeric states by intermediate energy protons at the Moscow Meson Factory of the Russian Academy of Sciences’ Institute for Nuclear Research

Isomeric ratios of reaction products obtained by irradiating 197Au, 181Ta, and 93Nb targets by protons with energies of 143–325 MeV are measured via activation. The results do not agree with measurements of stopped ions [1], even though the theoretical model in [2] predicted the same mechanism for the formation of high-spin isomers in these reactions. The obtained isomeric ratios in reactions with protons of intermediate energy are 10–100 times lower than the theoretical values; consequently, the excitation mechanisms of high-spin isomers in reactions with protons and stopped ions are different.