High-spin states and collective band structures in the odd–odd 140Pm nucleus
TL;DR: In this article, the high-spin states of 140Pm have been investigated through the reaction 126Te(19F, 5n) at a beam energy of 90 MeV.
Abstract: The high-spin states of 140Pm have been investigated through the reaction 126Te(19F, 5n) at a beam energy of 90 MeV. A previous level scheme based on the 8− isomer has been updated with spin up to 23 . A total of 22 new levels and 41 new transitions were identified. Six collective bands were observed. Five of them were expanded or re-constructed, and one of them was newly identified. The systematic signature splitting and inversion of the yrast πh11/2⊗νh11/2 band in Pr and Pm odd–odd isotopes has been discussed. Based on the systematic comparison, two ΔI = 2 bands were proposed as double-decoupled bands; other two bands with strong ΔI = 1 M1 transitions inside the bands were suggested as oblate bands with γ ~ −60°; another band with large signature splitting has been proposed with oblate-triaxial deformation with γ ~ −90°. The characteristics for these bands have been discussed.
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TL;DR: In this paper, the high-spin states of the oblate-triaxial deformation with high spins at a beam energy of 90 MeV have been investigated through the reaction.
Abstract: The high-spin states of $^{141}\mathrm{Pm}$ have been investigated through the reaction $^{126}\mathrm{Te}$($^{19}\mathrm{F}$,4$n$) at a beam energy of 90 MeV. A previous level scheme has been updated with spins up to 49/2$\ensuremath{\hbar}$. Six collective bands at high spins are newly observed. Based on the systematic comparison, one band is proposed as a decoupled band; two bands with strong $\ensuremath{\Delta}I=1$ $M1$ transitions inside the bands are suggested as the oblate bands with $\ensuremath{\gamma}$ $~$$\ensuremath{-}{60}^{\ifmmode^\circ\else\textdegree\fi{}}$; three other bands with large signature splitting have been proposed with the oblate-triaxial deformation with $\ensuremath{\gamma}$$~$ $\ensuremath{-}{90}^{\ifmmode^\circ\else\textdegree\fi{}}$. The triaxial $n$-particle-$n$-hole particle rotor model calculations for one of the oblate bands in $^{141}\mathrm{Pm}$ are in good agreement with the experimental data. The other characteristics for these bands have been discussed.
4 citations
TL;DR: In this article, a newly developed digital data acquisition system, which is based on the digital pulse processor Pixie-16 modules by XIA LLC, was tested with the $$\gamma$$ -ray detector array of the China Institute of Atomic Energy using the in-beam $$ \gamma-gamma Ｗ -ray source.
3 citations
TL;DR: In this paper, the high spin states in the odd-odd 138Pm nucleus have been reinvestigated via the 124Te(19F, 5n) reaction at the beam energy of 103 MeV.
Abstract: The high-spin states in the odd-odd 138Pm nucleus have been reinvestigated via the 124Te(19F, 5n) reaction at the beam energy of 103 MeV. Most of the known transitions and levels are confirmed. A number of bands are revised and one new band has been established. For the yrast πh
11/2⊗νh
11/2 band based on 8+ state, no evidence supporting the occurence of signature inversion is found. The experimental and theoretical B(M1)/B(E2) ratios have been calculated for band (2), which support the πg
7/2[413]5/2+ ⊗ νh
11/2[514]9/2− Nilsson configuration assignment. Four bands with ΔI = 2 transitions are tentatively assigned as doubly decoupled bands. The other three bands are proposed as oblate-triaxial bands. The possible configuration assignments for these bands are also discussed under the calculations of total Routhian surface and particle-rotor model.
3 citations
TL;DR: In this article, a systematic investigation on the low-lying spectra in N = 78 ~ 80 isotones is performed, and good systematics have been found for the coupling patterns which couple the odd nucleon(s), such as πh11/2,, to the 2+, 4+, 6+ and 3-core excitations.
Abstract: Combining the new spectroscopy results of 144Tb and previous spectroscopy studies of neighboring nuclei, a systematic investigation on the low-lying spectra in N = 78 ~ 80 isotones is performed. Good systematics have been found for the coupling patterns which couple the odd nucleon(s), such as πh11/2, , to the 2+, 4+, 6+ and 3- core excitations. It is found that the relative excitation energies of the states formed by coupling h11/2 proton(s) to the 2+, 4+ core excitations are pushed up, in contrast with those formed by coupling h11/2 neutron hole(s) to the 2+, 4+ core excitations, which are pulled down. According to the systematics, the interpretation that the 17/2+ states observed in 141Sm and 143Gd are the fully aligned member of coupling the odd h11/2 neutron hole to the octupole 3- core excitation, is explored to the isotones 145Dy, 142Eu, and 144Tb.
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01 Jul 1995-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this article, a level scheme is proposed to calculate an expected spectrum for comparison with the observed spectrum, and a graphics-based editor is included to allow fast and easy modification of the proposed level scheme, and least-squares fits to the matrix or cube can be performed to extract optimum values for the energies and intensities of the level scheme transitions.
Abstract: Programs for analysis of γ-γ matrices and γ-γ-γ cubes from HPGe coincidence experiments are described. The programs are intended primarily for high-spin spectroscopy studies. Users are able to inspect background-subtracted gated spectra, or combinations of such spectra, quickly and easily. The programs also make use of a proposed level scheme, provided by the user, to calculate an expected spectrum for comparison with the observed spectrum. Electron conversion coefficients, detection efficiency and γ-ray energy calibrations are included in the calculation. A graphics-based editor is included to allow fast and easy modification of the proposed level scheme, and least-squares fits to the matrix or cube can be performed to extract optimum values for the energies and intensities of the level scheme transitions.
620 citations
TL;DR: The collective and non-collective high-spin configurations in selected A ⋍ 80 nuclei are analyzed in detail using a shell-correction approach taking care of individual configurations and the pairing self-consistent cranking method with a non-axially deformed Woods-Saxon potential as discussed by the authors.
469 citations
TL;DR: In this article, a cranked modified-oscillator model was used to study the nuclear potential energy surface (based on a Strutinsky type of shell correction method) for very high angular momenta (30 ≦ I ≦ 100).
361 citations
TL;DR: In this paper, the energy levels required for the calculations are obtained from the folded-Yukawa single-particle model for ground-state shapes obtained in the macroscopic-microscopic approach by minimizing the total potential energy with respect to ϵ 2 and ϵ 4 shape degrees of freedom.
302 citations
TL;DR: Aplanar solutions of 3D tilted axis cranking calculations for triaxial shapes define left- and right-handed chiral systems out of the three angular momenta provided by the valence particles and the core rotation, which leads to spontaneous chiral symmetry breaking and the doublet bands.
Abstract: New sideband partners of the yrast bands built on the $\ensuremath{\pi}{h}_{11/2}\ensuremath{
u}{h}_{11/2}$ configuration were identified in ${}_{55}\mathrm{Cs}$, ${}_{57}\mathrm{La}$, and ${}_{61}\mathrm{Pm}$ $N\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}75$ isotones of ${}^{134}\mathrm{Pr}$. These bands form with ${}^{134}\mathrm{Pr}$ unique doublet-band systematics suggesting a common basis. Aplanar solutions of 3D tilted axis cranking calculations for triaxial shapes define left- and right-handed chiral systems out of the three angular momenta provided by the valence particles and the core rotation, which leads to spontaneous chiral symmetry breaking and the doublet bands. Small energy differences between the doublet bands suggest collective chiral vibrations.
212 citations