Evidence for the I?=8?, K=8 isomeric state in184Hf

Abstract

Abstract. Using an 11.4MeV/u 136Xe beam of the UNILAC accelerator of GSI and a natw target. A=184 isobars were produced and separated by using an on-line mass separator. A new isomeric state was found in 184Hf. This state decays with a half-life of 48 (10)

Long-lived isomers in neutron-richZ=72–76 nuclides

“…Furthermore, although both Coriolis mixing and mixing between competing neutron and proton configurations play a role in the lighter isotopes [67,68], these are likely to be less relevant here. In the case of the neighbor 184 Hf, Krumbholz et al [41] noted that the strength of its E1 decay to the 8 + state of the ground-state band was in agreement with the extension of the E1 systematics. The variation with neutron number had been attributed to changing K mixing in the 8 + final state [69], the evidence for which was the correlation between the strengths and the dynamic moments of inertia of the ground-state bands.…”

“…A long-lived [48 (10) s] γ -decaying, K π = 8 − isomer at 1.272(1) MeV was known in 184 Hf from earlier work [41] and its observation here serves as a convenient check on our ion identification and decay observation. A total of 32 184 Hf m1,72+ ions were observed, seven of which decayed.…”

“…The isomer at 1.272(1) MeV [41] [7] to a partial γ -ray half-life that is much greater than the measured value of ∼ 12 min. This is consistent with the fact that this isomer is only seen to β decay.…”

“…We note that β decay was not previously identified as a decay mode from this isomer. This is a bare nucleus, therefore internal conversion is not possible, although the neutral-atom internal conversion coefficient for the 555-keV M2 transition that depopulates the isomer [41] is low (∼ 0.1 [47]), so the neutral-atom and bare-ion half-lives should be similar. The measured half-life of t A second higher-lying isomer was observed in the ESR (Fig.…”

Multipleβ−decaying states in194Re: Shape evolution in neutron-rich osmium isotopes

“…Fragmentation has proved to be an efficient tool for producing exotic nuclear species and when combined with high sensitivity γ-ray detection arrays, structural information can be gained for otherwise inaccessible nuclei [14][15][16][17]. The highest sensitivity is achieved with both isomeric and β-delayed γ-ray spectroscopy techniques.…”