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

Authors :: Leppänen, A.-P.
Uusitalo, J.
Eeckhaudt, S.
Enqvist, T.
Eskola, K.
Grahn, T.
Heßberger, F. P.
Greenlees, P. T.
Jones, P.
Julin, R.
Juutinen, S.
Kettunen, H.
Kuusiniemi, P.
Leino, M.
Nieminen, P.
Pakarinen, J.
Perkowski, J.
Rahkila, P.
Scholey, C.
Sletten, G.
Source :: AIP Conference Proceedings. 2006, Vol. 831 Issue 1, p487-489. 3p. 2 Charts, 2 Graphs.
Publication Year :: 2006
Abstract: Neutron-deficient uranium isotopes 218U and 219U were studied via α spectroscopic methods. The isotopes were produced in fusion evaporation reaction 182W(40Ar,xn)222-xnU. The ground state decay properties of 218U were measured with improved statistics and in addition a low-lying α decaying isomeric state was discovered. The isomer in 218U decays by α emission with an energy of Eα=10 678(17) keV and with a half-life of T1/2=(0.56-0.14+0.26) ms. The new isomeric state was assigned spin and parity IΠ = 8+. The ground state α decay has an energy of Eα=8612(9) keV and a half-life of T1/2=(0.51-0.10+0.17) ms. The ground state decay properties of 219U were determined with improved statistics as Eα=9774(18) keV and a half-life of T1/2= (0.08-0.03+0.10) ms. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]