Study of the high-spin structure of 144Gd

doi:10.1016/0375-9474(94)90809-5

Nuclear Physics A

Volume 579, Issues 1–2, 17 October 1994, Pages 319-331

https://doi.org/10.1016/0375-9474(94)90809-5 Get rights and content

Abstract

High-spin states in ¹⁴⁴Gd have been investigated through the ¹⁰⁸Pd(⁴⁰Ar, 4n) reaction. An extended level scheme is proposed. A ridge structure has been observed in a γγ coincidence matrix, consistent with energy spacings in the superdeformed bands of neighbouring nuclei. Several discrete high-spin sequences have been observed. They are interpreted in the context of cranked-Strutinsky-type calculations in terms of different coexisting shapes.

References (27)

ChasmanR.R.
Phys. Lett.
(1987)
NazarewiczW. et al.
Nucl. Phys.
(1989)
MariscottiM.A.J. et al.
Nucl. Phys.
(1978)
HäusserO. et al.
Nucl. Phys.
(1982)
ClarkR.M. et al.
Phys. Lett.
(1992)
ClarkR.M. et al.
Nucl. Phys.
(1993)
BaldsiefenG. et al.
Phys. Lett.
(1992)
BaldsiefenG. et al.
Nucl. Phys.
(1994)
WyssR. et al.
Phys. Lett.
(1988)
DudekJ. et al.
Phys. Rev. Lett.
(1987)

LachM. et al.

Z. Phys.

(1984)

DafniE. et al.

Phys. Rev. Lett.

(1984)

SchutzY. et al.

Phys. Rev.

(1987)

Cited by (19)

Systematic decay studies of even-even 132-138Nd, 144-158Gd, 176-196Hg and 192-198Pb isotopes
2010, Nuclear Physics A
The alpha and cluster decay properties of the ^132–138Nd, ^144–158Gd, ^176–196Hg and ^192–198Pb even–even isotopes in the two mass regions $A = 130 – 158$ and $A = 180 – 198$ are analyzed using the Coulomb and Proximity Potential Model. On examining the clusters at corresponding points in the cold valleys (points with same $A_{2}$ ) of the various isotopes of a particular nucleus we find that at certain mass numbers of the parent nuclei, the clusters emitted are getting shifted to the next lower atomic number. It is interesting to see that the change in clusters appears at those isotopes where a change in shape is occurring correspondingly. Such a change of clusters with shape change is studied for the first time in cluster decay. The alpha decay half lives of these nuclei are computed and these are compared with the available experimental alpha decay data. It is seen that the two are in good agreement. On making a comparison of the alpha half lives of the normal deformed and superdeformed nuclei, it can be seen that the normal deformed ¹³²Nd, ^176–188Hg and ¹⁹²Pb nuclei are found to be better alpha emitters than the superdeformed (in excited state) ^134,136Nd, ^190–196Hg and ¹⁹⁴Pb nuclei. The cluster decay studies reveal that as the atomic number of the parent nuclei increases the $N \neq Z$ cluster emissions become equally or more probable than the $N = Z$ emissions. On the whole the alpha and cluster emissions are more probable from the parents in the heavier mass region ( $A = 180 – 198$ ) than from the parents in the lighter mass region ( $A = 130 – 158$ ). The effect of quadrupole ( $β_{2}$ ) and hexadecapole ( $β_{4}$ ) deformations of parent and fragments on half life times are also studied.
Study of yrast band in 155Tm
2007, Nuclear Physics A
Nuclear data sheets for A = 144
2001, Nuclear Data Sheets
Experimental data on ground- and excited-state properties for all nuclei with mass number A = 144 have been compiled and evaluated. States populated in radioactive decay as well as in nuclear reactions have been considered. For these nuclei, level and decay schemes have been built, as well as tables of nuclear properties. This work supersedes the 1989 evaluation by J.K. Tuli (1989Tu02). Manuscripts published before December 2000 have been included in this work.
From highly to superdeformed shapes: Study of 143Gd
2000, Nuclear Physics A
A superdeformed band has been discovered in ¹⁴³Gd consisting of 15 transitions. It does not show the band crossing observed in the neighbouring heavier Gd isotopes and it is degenerate with the superdeformed band in ¹⁴³Eu. In contrast to other degenerate bands at superdeformed shape, the configurations of the bands are quite different here. They result from the exchange of a ν6₄ with a π[404]9/2 configuration. In addition, a collective band has been observed which adopts a well-deformed triaxial shape at high spins according to calculations. The transition from highly to superdeformed shapes proceeds via triaxial shapes.
Influence of the entrance channel in the fusion reaction 318 MeV 74Ge+74Ge
1998, Nuclear Physics A
Entrance channel effects in the fusion of heavy ions have been studied by using the ⁷⁴Ge+⁷⁴Ge reaction at 318 MeV. The population of the yrast superdeformed band in ¹⁴⁴Gd shows an increase when compared with the results obtained in the more asymmetric ⁴⁸Ti+¹⁰⁰Mo reaction at 215 MeV. The relative yields of the different evaporation residues produced in the ⁷⁴Ge+⁷⁴Ge and in the ⁴⁸Ti+¹⁰⁰Mo reactions are very similar, with the exception of the ^145,144Gd residual nuclei (3n and 4n decay channels) which are populated with a larger yield in the symmetric reaction. Statistical model calculations reproduce qualitatively such effect if a fission delay is explicitly taken into account. Effects related to fusion barrier fluctuations seem to be important in determining the spin distributions of the compound nucleus. The spectra of the high energy γ-rays emitted in the ⁷⁴Ge+⁷⁴Ge reaction have been measured as a function of the γ-ray multiplicity as well as in coincidence with selected evaporation residues. They are reproduced by standard statistical model calculations with GDR parameters taken from systematics, demonstrating that, in agreement with dynamical model prediction, the emission of γ-rays from the dinucleus formed in the earlier stage of the collision is unimportant.
Proton excitations across the Z = 64 gap in the doubly magic superdeformed nucleus 144Gd
1997, Nuclear Physics A
Five superdeformed (SD) bands have been identified in ¹⁴⁴Gd with the GASP array using the reaction $^{100} Mo +^{48} Ti$ . The J⁽²⁾ moments of inertia of the four excited SD bands are flat as a function of rotational frequency, indicating the blocking of the N = 6 proton crossing observed in the yrast SD band. According to cranked shell model calculations, the excited bands have two-quasiproton configurations with one proton in the N = 6 orbital and the other in each signature partner of the $[404]9 2^{+}$ or $[411]3 2^{+}$ orbitals, lying above the Z = 64 gap. The interpretation of the excited SD bands in terms of proton excitations points to the high stability of the N = 80 shell closure at SD shapes. The population of the yrast SD band as a function of the beam energy has been also investigated. Our data shows that the intensity of the yrast SD band is not configuration dependent, being comparable to that of yrast SD bands in the neighboring nuclei. By comparing experimental and theoretical alignments, spins and configurations are assigned to all observed SD bands in the A = 140–150 region.

View all citing articles on Scopus

: The work was in part funded by the German Federal Ministry for Research and Technology (BMFT) under the contract number 060K602I.

¹: We would like to thank the VICKSI accelerator staff for providing the beams. The technical assistance of Mr. H.M. Jäger is greatly appreciated.

View full text

Article preview

Nuclear Physics A

Abstract

References (27)

Phys. Lett.

Nucl. Phys.

Nucl. Phys.

Nucl. Phys.

Phys. Lett.

Nucl. Phys.

Phys. Lett.

Nucl. Phys.

Phys. Lett.

Phys. Rev. Lett.

Z. Phys.

Phys. Rev. Lett.

Phys. Rev.

Cited by (19)

Systematic decay studies of even-even <sup>132-138</sup>Nd, <sup>144-158</sup>Gd, <sup>176-196</sup>Hg and <sup>192-198</sup>Pb isotopes

Study of yrast band in <sup>155</sup>Tm

Nuclear data sheets for A = 144

From highly to superdeformed shapes: Study of <sup>143</sup>Gd

Influence of the entrance channel in the fusion reaction 318 MeV <sup>74</sup>Ge+<sup>74</sup>Ge

Proton excitations across the Z = 64 gap in the doubly magic superdeformed nucleus <sup>144</sup>Gd