Eur. Phys. J. A 10, 135-138

Depopulation of the isomer in to the ground state by Coulomb excitation

Ch. Schlegel^{1, 2}, P. von Neumann-Cosel¹, J. de Boer³, J. Gerl², M. Kaspar², I. Kozhoukharov², M. Loewe³, H.J. Maier³, P.J. Napiorkowsky⁴, I. Peter², M. Rejmund², A. Richter¹, H. Schaffner², J. Srebrny⁵, M. Würkner³, H.J. Wollersheim² and the EBGSI96-Collaboration<sup>5

1</sup>  Institut für Kernphysik, Technische Universität Darmstadt, D-64289 Darmstadt, Germany
²  Gesellschaft für Schwerionenforschung, Planckstrasse 1, D-64291 Darmstadt, Germany
³  Sektion Physik, Universität München, D-85748 Garching, Germany
⁴  Heavy Ion Laboratory, Warsaw University, PL-02-093 Warsaw, Poland
⁵  Institute of Experimental Physics, Warsaw University, ul. Hoza 69, PL-00-681 Warsaw, Poland

vnc@ikp.tu-darmstadt.de

(Received: 23 January 2001 Communicated by D. Schwalm)

Abstract
In-beam Coulomb excitation of the exotic odd-odd nucleus ¹⁸⁰Ta has been studied by using a ¹³⁶Xe beam and a setup consisting of five EUROBALL CLUSTER detectors and the Darmstadt-Heidelberg Crystal Ball array. Spectroscopic information on the extremely rare ¹⁸⁰Ta is obtained from the comparison between an enriched (% ¹⁸⁰Ta) and a natural tantalum target. Possible evidence for a depopulation from the long-lived high-spin isomer to the short-lived ground state is searched for by different methods. The decay of low-K bandheads, which are nanosecond isomers, towards the ground-state band can be demonstrated in delayed spectroscopy. A coincidence analysis provides indications of K = 5 in-band transitions. Finally, when the Crystal Ball is used as an energy and multiplicity filter, signals of decay into the K = 0 band are observed.

PACS
25.70.De - Coulomb excitation.
27.70.+q - .
23.90.+w - Other topics in radioactive decay and in-beam spectrospcopy.

© Società Italiana di Fisica, Springer-Verlag 2001