2023 Impact factor 2.6
Hadrons and Nuclei
Eur. Phys. J. A 6, 269-273

Fine Structure in the alpha decays of 226U and 230Pu

P.T. Greenlees1 - P. Kuusiniemi2 - N. Amzal1 - A. Andreyev3 - P.A. Butler1 - K.J. Cann1 - J.F.C. Cocks1,2 - O. Dorvaux2 - T. Enqvist2,7 - P. Fallon4 - B. Gall6 - M. Guttormsen5 - D. Hawcroft1 - K. Helariutta2 - F.P. Hessberger7 - F. Hoellinger6 - G.D. Jones1 - P. Jones2 - R. Julin2 - S. Juutinen2 - H. Kankaanpää2 - H. Kettunen2 - M. Leino2 - S. Messelt5 - M. Muikku2 - S. Ødegå rd5 - R.D. Page1 - A. Savelius2 - A. Schiller5 - S. Siem5 - W.H. Trzaska2 - T. Tveter5 - J. Uusitalo2

1 Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, UK
2 Department of Physics, University of Jyväskylä, 40351 Jyväskylä, Finland
3 Joint Institute for Nuclear Research, 141980 Dubna, Russia
4 Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
5 Department of Physics, University of Oslo, 0316 Oslo, Norway
6 Centre de Recherches Nucléaires, 67037 Strasbourg Cedex, France
7 Gesellschaft für Schwerionenforschung, 64220 Darmstadt, Germany

Received: 13 April 1999 / Revised version: 07 July 1999 Communicated by J. Äystö

The nuclei 226U and 230Pu have been populated via reactions involving 208Pb targets bombarded by 22Ne and 26Mg projectiles. Fusion-evaporation residues were separated in-flight using a gas-filled recoil separator. A position-sensitive Si-strip detector was employed at the focal plane in order to identify correlated $\alpha$-decay chains. Two fine structure $\alpha$-decay lines have been observed. The first, with an energy of 7385(5) keV, is assigned as the $\alpha$ decay from 226U to the first excited 2+ state of 222Th. The second line, observed for the first time in this work, has an energy of 6961(30) keV and is assigned as the $\alpha$ decay from 230Pu to the first excited 2+ state of 226U. The excitation energy of the first excited 2+ state in 226U was determined to be 96(25) keV, giving an estimate of the deformation parameter $\beta_{2}\simeq$ 0.20.

23.60 +e $\alpha$ decay - 27.90 +b $220 \le A$ - 25.70 -z Low and intermediate energy heavy-ion reactions

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