https://doi.org/10.1140/epja/i2012-12032-7
Regular Article - Experimental Physics
The source of “background” fission events in experiments on superheavy elements
1
GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291, Darmstadt, Germany
2
Institut für Physik, Goethe-Universität Frankfurt, 60054, Frankfurt, Germany
3
Helmholtz Institut Mainz, 55099, Mainz, Germany
* e-mail: s.heinz@gsi.de
Received:
18
January
2012
Revised:
15
February
2012
Accepted:
23
February
2012
Published online:
19
March
2012
In experiments for the synthesis of superheavy elements at the velocity filter SHIP, GSI, we observed fission events, which could not be attributed to decay chains of superheavy isotopes from fusion reactions. Usually, the observation of spontaneous fission is a crucial first step for the detection of decay chains. In order to avoid random correlations and misidentifications of superheavy isotopes, it is therefore essential to know the features and cross-sections of fission events not originating from decay chains of superheavy nuclei. The special properties of the velocity filter allowed us to identify and study the “background” fission events as decay products of heavy target-like nuclides populated in nucleon transfer reactions. Here, we will discuss the results obtained in collisions of 20 48 Ca + 96 248 Cm, 24 54 Cr + 96 248 Cm and 28 64 Ni + 92 238 U, which were applied for the synthesis of elements Z = 116 and 120, respectively.
© SIF, Springer-Verlag Berlin Heidelberg, 2012
