α-decay spectroscopy of the N = 130 isotones 218Ra and 220Th: Mitigation of α-particle energy summing with implanted nuclei
Parr, E.; Smith, J. F.; Greenlees, P. T.; Auranen, K.; Butler, P. A.; Chapman, R.; Cox, D. M.; Cullen, D. M.; Gaffney, L. P.; Grahn, T.; Gregor, E. T.; Grocutt, L.; Herzán, A.; Herzberg, R.-D. et al. (2019). α-decay spectroscopy of the N = 130 isotones 218Ra and 220Th: Mitigation of α-particle energy summing with implanted nuclei. Physical Review C, 100 (4), 044323. DOI: 10.1103/PhysRevC.100.044323
Published inPhysical Review C
Parr, E. |
© 2019 American Physical Society
An analysis technique has been developed in order to mitigate energy summing due to sequential short-lived α decays from nuclei implanted into a silicon detector. Using this technique, α-decay spectroscopy of the N=130 isotones 218Ra (Z=88) and 220Th (Z=90) has been performed. The energies of the α particles emitted in the 218Ra→214Rn and 220Th→216Ra ground-state-to-ground-state decays have been measured to be 8381(4) keV and 8818(13) keV, respectively. The half-lives of the ground states of 218Ra and 220Th have been measured to be 25.99(10) μs and 10.4(4) μs, respectively. The half-lives of the ground states of the α-decay daughters, 214Rn and 216Ra, have been measured to be 259(3) ns and 161(11) ns, respectively. Fine structure in the α decay of 218Ra has been observed for the first time, populating the 695-keV 2+1 state in 214Rn. The fine-structure α decay has an α-particle energy of 7715(40) keV and branching ratio bα=0.123(11)%.