Spin of the Ra219 ground state

The Pb208(18O,3n)223Th reaction at 83 MeV bombarding energy was used to populate the alpha-radioactive nucleus Th223. Out-of-beam alpha-gamma coincidences were recorded at correlation angles of 90° and 180°. The a2 angular correlation coefficient was extracted for an alpha-gamma cascade to the Rn215 ground state via the 0.316 MeV excited state. This limited the assignment of the ground-state spin of Ra219 to ((7/2, 11) / 2 )+. .AE