Bonn 2010 – wissenschaftliches Programm
HK 36.21: Poster
Mittwoch, 17. März 2010, 14:00–16:00, HG Aula
Investigation of the triple-humped fission barrier of 233Th — •Lorant Csige1, Margit Csatlos3, Attila Krasznahorkay3, Peter Thirolf1, Thomas Faestermann2, Janos Gulyas3, Dieter Habs1, Ralf Hertenberger1, Rudi Lutter1, Tamas Tornyi3, and Hans-Friedrich Wirth2 — 1Ludwig Maximilians Universitat, Munich, Germany — 2Technische Universitat, Munich, Germany — 3Inst. of Nucl. Res. of the Hun. Acad. of Sci.
Previously, sharp fission resonances were observed by Blons and coworkes  and interpreted by them as the consequence of a theoretically predicted (hyperdeformed) third potential minimum. They suggested that the observed resonances appeared at those energies where the nucleus has excited states in the third minimum of the multiple-humped potential barrier.
Sharp resonance bands were observed for the first time in the fission probability of the 234U and 236U isotopes, supporting the existence of a deep third minimum of the potential barrier, in good agreement with theoretical predictions. In this theory also a deep third minimum is predicted for 232Th. However, even in the latest cross section calculations a very shallow one was successfully used in reproducing the prompt fission cross sections.
In order to get more insight into the fission barrier landscape of 232Th a new experiment has been performed at the Munich Tandem accelerator using the 232(d,pf) reaction, which excites higher spin states compared to the (n,f) reaction.  J. Blons et al., Phys. Rev. Lett. 35 (1975) 174