Eur. Phys. J. A (2012) 48: 75
https://doi.org/10.1140/epja/i2012-12075-8

Regular Article - Experimental Physics

Alpha-gamma decay studies of ²⁵³No and its daughter products ²⁵³Md , ²⁴⁹Fm

¹ GSI, Helmholtzzentrum für Schwerionenforschung GmbH, 64291, Darmstadt, Germany
² Helmholtz Institut Mainz, 55099, Mainz, Germany
³ Department of Nuclear Physics and Biophysics, Comenius University, 84248, Bratislava, Slovakia
⁴ Institut für Kernphysik, Goethe-Universität, 60054, Frankfurt am Main, Germany
⁵ University of Jyväskylä, 40361, Jyväskylä, Finland
⁶ Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, 319-1195, Ibaraki, Japan

Received: 23 January 2012
Accepted: 17 April 2012
Published online: 29 May 2012

Abstract

Nuclear structure and decay of the isotope ²⁵³No and its decay products ²⁴⁹Fm and ²⁵³Md were investigated by means of - spectroscopy. Besides the established strong transitions from the Nilsson level in ²⁴⁹Fm , populated predominantly by the decay of ²⁵³No , into the ground-state (gs) rotational band, a couple of weaker lines (58.3, 129.2, 209.3 and 669.5keV) were observed and placed into the ²⁴⁹Fm level scheme. The transition from the level in ²⁴⁹Es , populated by the decay of ²⁵³Md , into the member of the gs rotational band, so far established for other odd-mass Es isotopes, was observed clearly. GEANT4 simulations were performed to investigate the influence of energy summing between particles and conversion electrons (CE) on the shape of the spectra at different implantation energies, leading to evidence for a weak decay branch of ²⁵³No into the gs of ²⁴⁹Fm or the ground-state rotational band, respectively.