Eur. Phys. J. A (2005) 25: 183-184
https://doi.org/10.1140/epjad/i2005-06-116-y

ENAM 2004

Alpha-decay study of ²¹⁸U; a search for the sub-shell closure at Z = 92

¹ Department of Physics, University of Jyväskylä, P.O. Box 35, FIN-40351, Jyväskylä, Finland
² Department of Physics, University of Helsinki, FIN-00014, Helsinki, Finland
³ GSI, Planckstr. 1, D-64291, Darmstadt, Germany
⁴ Department of Physics, University of Copenhagen, Copenhagen, Denmark

Received: 4 November 2004
Accepted: 24 March 2005
Published online: 22 June 2005

Abstract

Neutron-deficient uranium isotopes were studied via α spectroscopic methods. A low-lying α-decaying isomeric state was found in ²¹⁸U. The new isomeric state was assigned spin and parity I ^π=8⁺. The isomer decays by α emission with an energy E = 10678(17)keV and with a half-life T _1/2 = (0.56^+0.26 _-0.14)ms. The known alpha-decay properties of the ground state of ²¹⁸U was measured with improved statistics. The ground-state α-decay has an energy E = 8612(9)keV and a half-life T _1/2 = (0.51^+0.17 _-0.10)ms.