Low-spin excitations in the 109Tc nucleus
Kurpeta, J., Urban, W., Płochocki, A., Rissanen, J., Pinston, J. A., Elomaa, V.-V., . . . Äystö, J. (2012). Low-spin excitations in the 109Tc nucleus. Physical Review C, 86 (4), 044306. doi:10.1103/PhysRevC.86.044306
Published inPhysical Review C
© 2012 American Physical Society. Published in this repository with the kind permission of the publisher.
Monoisotopic samples of 109Mo nuclei, produced in the deuteron-induced fission of 238U and separated using the IGISOL mass separator coupled to a Penning trap, were used to perform β- and γ -coincidence spectroscopy of 109Tc. Spin and parity 5/2+ for the ground state of 109Mo, proposed earlier, are supported in the present work. Three new low-energy levels observed in 109Tc are interpreted as bandheads of the π3/2−, π5/2−, and π1/2+ configurations, respectively. A further three levels observed around 0.4 MeV are interpreted as K = 1/2 triaxial excitations. A similar interpretation is proposed for an analogous set of three levels observed in 107Tc in another β− decay work. The systematics of these excitations breaks down in 111Tc, most likely due to a transition from prolate to oblate deformation. An excitation at 745.0 keV in 109Tc and 850.7 keV in 107Tc is interpreted as the π7/2+ configuration. Quasiparticle-rotor model calculations support the proposed interpretations. ...