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24.
VADER: A novel decay station for actinide spectroscopy Raggio, A.; Pohjalainen, I.; Rey-Herme, E. ...
Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms,
July 2023, 2023-07-00, Volume:
540
Journal Article
Peer reviewed
Open access
A research programme focused on the study of the nuclear structure of actinide isotopes has recently been implemented at the IGISOL facility, University of Jyväskylä. Within this scope, a new decay ...station named VADER (Versatile Actinides DEcay spectRoscopy setup) has been developed and commissioned. The system consists of a compact array of silicon detectors, a liquid-nitrogen-cooled silicon lithium (Si(Li)) detector and three broad energy germanium detectors (BEGe), placed around a thin implantation carbon foil. The combined use of different detectors allows the measurement of α particles, conversion electrons and de-excitation γ rays in coincidence, enabling a full reconstruction of nuclear decay schemes. The measurement of basic nuclear decay observables provides a picture of the nuclear shell evolution in neutron-deficient actinides, and highlights the possible emergence of reflection-asymmetric shapes in the region.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Here, shell evolution can impact the structure of the nuclei and lead to effects such as shape coexistence. The nuclei around 68Ni represent an excellent study case, however, spectroscopic ...information of the neutron-rich, Z < 28 nuclei is limited. The goal is to measure γ-ray transitions in 66Fe, 66Co, and 66Ni populated in the β– decay of 66Mn to determine absolute β feedings and relative γ-decay probabilities and to compare the results with Monte Carlo shell model calculations in order to study the influence of the relevant single neutron and proton orbital occupancies around Z = 28 and N = 40. The low-energy structures of 65,66Fe, 66Co, and 66Ni were studied in the β– decay of 66Mn produced at ISOLDE, CERN. The beam was purified by means of laser resonance ionization and mass separation. The β and γ events detected by three plastic scintillators and two MiniBall cluster germanium detectors, respectively, were correlated in time to build the low-energy excitation schemes and to determine the β-decay half-lives of the nuclei. As a result, the relative small β-decay ground state feeding of 66Fe obtained in this work is at variant to the earlier studies. Spin and parity 1+ was assigned to the 66Co ground state based on the strong ground-state feeding in the decay of 66Fe as well as in the decay of 66Co. Experimental log(ft) values, γ-ray de-excitation patterns, and energies of excited states were compared to Monte Carlo shell model calculations. Based on this comparison, spin and parity assignments for the selected number of low-lying states in the 66Mn to 66Ni chain were proposed. In conclusion, the β-decay chain starting 66Mn toward 66Ni, crossing N = 40, evolves from deformed nuclei to sphericity. The β-decay population of a selected number of 0+ and 2+ states in 66Ni, which is understood within shape coexistence framework of Monte Carlo shell model calculations, reveals the crucial role of the neutron 0g9/2 shell and proton excitations across the Z = 28 gap.
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A detailed β -decay study of the low- and high-spin states in Bi 216 has been performed at the ISOLDE Decay Station at the CERN-ISOLDE facility. In total, 48 new levels and 83 new transitions in the ...β -decay daughter Po 216 were identified. Shell-model calculations for excited states in Bi 216 and Po 216 were performed using the H208 and the modified Kuo-Herling particle effective interactions. Based on the experimental observations and the shell-model calculations, the most likely spin and parity assignments for the β -decaying states in Bi 216 are ( 3 − ) and ( 8 − ) , respectively. Published by the American Physical Society 2024
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We report on the precise mass measurement of the
173
Hf isotope performed at the Ion Guide Isotope Separator On-Line facility using the JYFLTRAP double Penning trap mass spectrometer. The new ...mass-excess value,
ME
=
-
55390.8
(
30
)
keV, is in agreement with the literature while being nine times more precise. The newly determined
173
Hf electron-capture
Q
value,
Q
EC
=
1490.2
(
34
)
keV, allows us to firmly reject the population of an excited state at 1578 keV in
173
Lu and 11 transitions tentatively assigned to the decay of
173
Hf. Our refined mass value of
173
Hf reduces mass-related uncertainties in the reaction rate of
174
Hf
(
γ
,
n
)
173
Hf. Thus, the rate for the main photodisintegration destruction channel of the
p
nuclide
174
Hf in the relevant temperature region for the
γ
process is better constrained.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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