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

. Nuclear structure and decay of the isotope 253 No and its decay products 249 Fm and 253 Md were investigated by means of - spectroscopy. Besides the established strong transitions from the Nilsson level in 249 Fm , populated predominantly by the decay of 253 No , 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 249 Fm level scheme. The transition from the level in 249 Es , populated by the decay of 253 Md , 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 253 No into the gs of 249 Fm or the ground-state rotational band, respectively.