| Popis: |
To study fission characteristics of protactinium-232, the isotope under investigation was built up in the 232 Th(p, n) reaction at a proton energy of E p ≈ 11.5MeV. At irradiating the layer by thermal and resonance neutrons the short-lived components with a half-decay period of ∼ 6hours were found in the yields of fission fragments. The totality of experimental data can be explained by the fact that at the thorium-232 bombardment by accelerated protons the protactinium-232 nuclei are formed in the isomer state with a half-life of T1/2 ≈ 2.3hour. The isomer of 232m Pa decays approximately with the similar probability by isomer transition to the ground state 232 Pa and, as a result of α-decay, to the isotope 228 Ac (T1/2 = 6.15hour). |
