β -delayed fission and α decay of at 196

A nuclear-decay spectroscopy study of the neutron-deficient isotope At-196 is reported where an isotopically pure beam was produced using the selective Resonance Ionization Laser Ion Source and On-Line Isotope Mass Separator (CERN). The fine-structure alpha decay of At-196 allowed the low-energy excited states in the daughter nucleus Bi-192 to be investigated. A beta-delayed fission study of At-196 was also performed. A mixture of symmetric and asymmetric fission-fragment mass distributions of the daughter isotope Po-196 (populated by beta decay of At-196) was deduced based on the measured fission-fragment energies. A beta DF probability P-beta DF(At-196) = 9(1) x 10(-5) was determined.