-delayed fission and decay of At

Truesdale, V. L.*; Andreyev, A. N.; Ghys, L.*; Huyse, M.*; Van Duppen, P.*; Sels, S.*; Andel, B.*; Antalic, S.*; Barzakh, A.*; Capponi, L.*; Cocolios, T. E.*; Derkx, X.*; De Witte, H.*; Elseviers, J.*; Fedorov, D. V.*; Fedosseev, V. N.*; Heberger, F. P.*; Kalaninov, Z.*; Kster, U.*; Lane, J. F. W.*; Liberati, V.*; Lynch, K. M.*; Marsh, B. A.*; Mitsuoka, Shinichi; Nagame, Yuichiro ; Nishio, Katsuhisa   ; Ota, Shuya*; Pauwels, D.*; Popescu, L.*; Radulov, D.*; Rapisarda, E.*; Rothe, S.*; Sandhu, K.*; Seliverstov, M. D.*; Sjdin, A. M.*; Van Beveren, C.*; Van den Bergh, P.*; Wakabayashi, Yasuo*

A nuclear-decay spectroscopy study of the neutron-deficient isotope At 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 decay of At allowed the low-energy excited states in the daughter nucleus Bi to be investigated. A -delayed fission study of At was also performed. A mixture of symmetric and asymmetric fission-fragment mass distributions of the daughter isotope Po (populated by decay of At) was deduced based on the measured fission-fragment energies. A DF probability (At) = 9(1)10 was determined.