2018 Impact factor 2.481
Hadrons and Nuclei
Eur. Phys. J. A 5, 399-408

The structure of 99Ru from ($\alpha$,3n) reaction

J. Mrázek1 - M.Honusek1 - A. Spalek1 - J. Bielcík1 - J. Slívová1 - J. Adam1 - A.A. Pasternak2

1 Nuclear Physics Institute, Academy of Sciences of the Czech Republic, Rez near Prague, Czech Republic
(e-mail: honusek@ujf.cas.cz)
2 Physical-Technical Institute "A.F. Joffe'', Cyclotron Laboratory, ul. Politechnitscheskaja 26, 194021 St. Petersburg, Russia

Received: 13 January 1999 / Revised version: 26 March 1999 Communicated by D. Schwalm

Abstract
The results of in-beam investigations of excited states of 99Ru using the 98Mo($\alpha$, 3n) reaction are presented. Angular distributions of $\gamma$-rays and $\gamma$-$\gamma$ coincidences have been measured. Excited states have been identified up to an energy of E = 5603 keV and spin of I$^{\pi}$ = 31/2-. Mean lifetimes $\tau$ have been determined using the DSA method for eleven levels. Aligned angular momenta are discussed and the probable $(\nu h_{11/2})$ origin of a backbending at frequency about 0.5 MeV was confirmed. The possible role of $(\nu d_{5/2})$ alignment at frequencies above 0.5 MeV was pointed out.

PACS
27.60.+j Properties of specific nuclei listed by mass ranges 90$\leq$A$\leq$149 - 23.20.Lv Gamma transitions and level energies - 23.20.Ck Lifetimes and transition probabilities - 23.20.En Angular distribution and correlation measurements


Copyright Springer-Verlag