The isotopes and were produced by the irradiation of with 35–45 MeV particles by and reactions and were removed from the target by a helium jet system. and - coincidence spectra were measured with Si and Ge(Li) detectors. From the EC decays of and levels in and were deduced. Favored decay of was found to populate the single-particle state in thus establishing the as the ground state. Several rays were observed in the - coincidence spectrum. is the heaviest nucleus in which excited intrinsic states have been identified.
- Received 9 November 1999
- Published 24 February 2000
© 2000 The American Physical Society