Application of Isochronous Mass Spectrometry for the study of angular momentum population in projectile fragmentation reactions

Isochronous mass spectrometry was applied to measure isomeric yield ratios of fragmentation reaction products. This approach is complementary to conventional gamma-ray spectroscopy in particular for measuring yield ratios for long-lived isomeric states. Isomeric yield ratios for the high-spin I = 19/2 (h) over bar states in the mirror nuclei Fe-53 and Co-53 are measured to study angular momentum population following the projectile fragmentation of Kr-78 at energies of similar to 480A MeV on a beryllium target. The 19/2 state isomeric ratios of Fe-53 produced from different projectiles in the literature have also been extracted as a function of mass number difference between projectile and fragment ( mass loss). The results are compared to (ABRABLA)07 model calculations. The isomeric ratios of Fe-53 produced using different projectiles suggest that the theory underestimates not only the previously reported dependence on the spin but also the dependence on the mass loss.