-decay spectroscopy of the new isotope At
新同位体Atの崩壊核分光
Andreyev, A. N.*; Antalic, S.*; Ackermann, D.*; Franchoo, S.*; Heberger, F. P.*; Hofmann, S.*; Huyse, M.*; Kojouharov, I.*; Kindler, B.*; Kuusiniemi, P.*; Lesher, S. R.*; Lommel, B.*; Mann, R.*; Mnzenberg, G.*; 西尾 勝久 ; Page, R. D.*; Ressler, J. J.*; Streicher, B.*; Saro, S.*; Sulignano, B.*; Van Duppen, P.*; Wiseman, D. R.*
Andreyev, A. N.*; Antalic, S.*; Ackermann, D.*; Franchoo, S.*; Heberger, F. P.*; Hofmann, S.*; Huyse, M.*; Kojouharov, I.*; Kindler, B.*; Kuusiniemi, P.*; Lesher, S. R.*; Lommel, B.*; Mann, R.*; Mnzenberg, G.*; Nishio, Katsuhisa; Page, R. D.*; Ressler, J. J.*; Streicher, B.*; Saro, S.*; Sulignano, B.*; Van Duppen, P.*; Wiseman, D. R.*
Decay properties of the new neutron-deficient nuclide At have been studied in the complete fusion reaction Sm(V,3n)At at the velocity filter SHIP of GSI. Two isomeric states with half-lives of 88(6) ms and 11.5(6) ms, respectively, and with complex -decay schemes were identified in At. The decay pattern of one of the isomers suggests that it is based on the oblate-deformed 2f7/2 1i13/2 configuration, which confirms the expected onset of deformation in the At isotopes by approaching the neutron midshell at N=104.