ALPHA DECAY OF 227U

The α spectrum of the U227 decay chain, previously reported in 1952 by Meinke et al., was investigated by bombarding Pa231 with protons from 35 to 54 MeV. The half-life of the parent nuclide U227 was found to be 1.1±0.1 min, in agreement with the earlier value of 1.3±0.3 min. The α-particle energies in the decay chain were determined more precisely than in the earlier study. In addition, some disagreement was found with the 1952 work. The nuclides and α-particle energies observed in the present investigation are as follows: U227, 6.87±0.02 MeV; Th223, 7.33±0.02 MeV; Ra219, 7.70±0.02 MeV (relative intensity 0.7±0.1) and 7.99±0.02 MeV (0.3±0.1); Rn215, 8.67±0.02 MeV; and Po211, 7.46±0.02 MeV. © 1969 The American Physical Society.