Low-lying structure of 215Rn and 219Ra

Excited states in 215Rn and 219Ra were populated by the alpha decay of 223Th (T12/=0.6 s), formed in the reaction 83 MeV 208Pb(18O,3n). Out-of-beam gamma rays and conversion electrons were observed in coincidence with the detection of alpha particles. These measurements enabled the low-lying structure of 215Rn and 219Ra to be deduced. The strongly populated states are found to be connected by M1 transitions which suggest that their configuration is ( nu g92/)/sup /n.