| Popis: |
The sequential decay 16 N(β − ) 16 O(α) 12 C from a gaseous source of 16 N has been investigated by analysing the energy spectrum of 34 × 10 6 alpha particles. A group of (1.84±0.33) × 10 4 alphas with an energy of 2017 ± 10 keV could be identified. These alphas are attributed to the decay from the 2 + , 9.85 MeV state in 16 O. For the 16 N beta-decay branch leading to this state, the value log ft = 8.8±0.1 has been deduced, which corresponds to a branching ratio of (6.5±2.0) × 10 −9 . Parity-forbidden alpha decay from the 16 O(2 − , 8.87 MeV) state has not been observed. The events which could be attributed to such a decay form a smaller fraction than 4 × 10 −3 % of the total number of 6 × 10 7 alphas obtained from several measurements. This corresponds to a width Γ α ≦ 0.94 × 10 −10 eV for this decay. |
