Spectroscopy and lifetime measurements of states inKr76populated inRb76

Abstract

The properties of the excited states of 76 Kr, populated in the decay of 76 Rb produced at ISOLDE isotopic separator, have been investigated by using K-conversion electron, γ -ray, and γ -γ coincidence measurements. The lifetimes of several levels have been measured by means of the advanced time-delayed βγ γ (t) method. The identification of 19 new levels and 55 transitions and the information deduced on spin and/or parity of the observed states from K-conversion coefficients, log ft values and decay properties have led to an improved knowledge of the level scheme. In particular, six 1 − states have been definitely identified and J π = 2 − has been assigned to the 2227 keV level, on which a band proposed to have negative-parity and even-spin had been previously observed. The strengths of the E0 and E2 transitions deexciting the 0

Fast-timing spectroscopy at ISOLDE

“…Spin-parity assignments for the low-lying negative parity 1 2 , 3 2 --, and 5 2 -states can be made based on the measured transition rates, and the positive parity levels are also identified. The structure is very similar to that observed in 63 Fe, where the half-lives of 805 (30) and 125(20) 66 Ni N=38 can be investigated in this way. Its structure is known from β-decay [52] and from deep-inelastic scattering [53], which shows a large population to the 0 3 + state at 2671 keV, above the second 0 2 + state at 2443 keV and the 2 1 + level at 1425 keV.…”

“…These results are compared with large-scale shell-model calculations based on the Lenzi-Nowacki-Poves-Sieja interaction [48]. Odd-A nuclei are specially suited for ATD t bgg ( ) studies, which has prompted the study of Fe isotopes to be extended to 61,63,65,67 Fe. The low energy structure of 63 Fe [49,50] and 65 Fe [51] has been studied in detail by means of γ-and fast-timing spectroscopy.…”

“…Odd-A nuclei are specially suited for ATD t bgg ( ) studies, which has prompted the study of Fe isotopes to be extended to 61,63,65,67 Fe. The low energy structure of 63 Fe [49,50] and 65 Fe [51] has been studied in detail by means of γ-and fast-timing spectroscopy. In [50] the level scheme of 65 Fe populated following the b -decay of 65 Mn was established for the first time, including the determination of the excitation energy of the β-decaying isomer at 393.7(2) keV.…”

Multipole Mixing Ratios of gamma -Transitions from Excited Levels of the 73As Nucleus Populated in the 73G(p, n gamma ) Nuclear Reactions

“…On the theoretical side, it can be calculated using the following expression (Giannatiempo, 2005;Raman, 2006) of the total conversion coefficient, α tot , for a mixed transition…”

“…Giannatiempo et al (2005) calculated the theoretical values for internal conversion coefficients with the aid of relation (3) and then compared with the experimental values when δ 2 has been evaluated.…”