https://doi.org/10.1140/epja/i2009-10899-9
Regular Article - Experimental Physics
Decay studies of K isomers in 254No
1
GSI, Helmholtzzentrum für Schwerionenforschung GmbH, 64291, Darmstadt, Germany
2
Department of Nuclear Physics and Biophysics, Comenius University Bratislava, 84248, Bratislava, Slovakia
3
Institut für Physik, Goethe-Universität Frankfurt, 60054, Frankfurt, Germany
4
St. Petersburg State University, 198504, Stari Peterhof, St. Petersburg, Russia
5
CUPP, University of Oulu, 90014, Oulu, Finland
6
Department of Physics, University of Jyväskylä, 40014, Jyväskylä, Finland
7
Japan Atomic Energy Agency, Tokai, 319-1184, Ibaraki, Japan
8
Flerov Laboratory of Nuclear Reactions, JINR, 141890, Dubna, Russia
* e-mail: F.P.Hessberger@gsi.de
Received:
12
May
2009
Revised:
16
October
2009
Accepted:
15
November
2009
Published online:
15
December
2009
A detailed 
spectroscopic decay study of two K isomers in 254No was performed. In addition to the previously reported lines two new transitions of E = 778 , 856keV could be attributed to the decay pattern of 254m1No ( T
1/2 = 275±7 ms). The population of an excited band built up on this isomer ( 
by the decay of 254m2No ( T
1/2 = 198±13 μs) could be proven by measuring delayed - coincidences between transitions stemming from the decay of both isomeric states. The energies of the band members could be established up to 
. A spontaneous fission branch of (2.0±1.2)×10-4 was measured for 254m1No , an upper limit of 
1.2×10-4 was estimated for 254m2No . These values demonstrate the high stability of multi-quasiparticle configurations against spontaneous fission. Evidence for an 
decay branch of 254m1No in the order of 1×10-4 was found.
© SIF, Springer-Verlag Berlin Heidelberg, 2010
