Band crossing in 186Hg

doi:10.1016/0375-9474(77)90119-1

Nuclear Physics A

Volume 284, Issue 2, 4 July 1977, Pages 221-238

https://doi.org/10.1016/0375-9474(77)90119-1 Get rights and content

Abstract

The decay of ¹⁸⁶Tl has been studied using the ISOCELE isotope separator operated on-line with the Orsay synchrocyclotron. A level scheme of ¹⁸⁶Hg is proposed; the 0⁺₂ and 2⁺₂ states at 523 keV and 620.8 keV, respectively, are the first members of a deformed rotational band which crosses the quasispherical ground-state one. Theoretical interpretations are given in the framework of available models.

References (33)

D. Proetel et al.
Nucl. Phys.
(1974)
D. Proetel et al.
Nucl. Phys.
(1974)
R.M. Lieder et al.
Nucl. Phys.
(1975)
J. Bonn et al.
Phys. Lett.
(1971)
P. Hornshøj et al.
Phys. Lett.
(1973)
M. Finger et al.
Nucl. Phys.
(1972)
N. Rud et al.
Phys. Rev. Lett.
(1973)
D. Proetel et al.
Phys. Rev. Lett.
(1973)
D. Proetel et al.
Phys. Lett.
(11974)
The Orsay on-line separator ISOCELE
(1976)
P. Paris et al.
Rev. Phys. Appl.
(1966)
J.T. Routti
UCRL 19452
(1969)
W. Watzig et al.
IPNO 75-03
(1975)
S. Hager and E. C. Seltzer, Nucl. Data Tables...

J.H. Hamilton et al.

Phys. Rev. Lett.

(1975)

A.V. Aldushchenkov et al.

Nucl. Data Tables

(1972)

M. Cailliau

Ph.D. thesis

(1974)

M.A. Deleplanque et al.

Compt. Rend.

(1975)

M.A. Deleplanque et al.

J. de Phys.

(1975)

C. Bourgeois et al.

M.A. Deleplanque et al.

J. de Phys. Lett.

(1975)

M.A. Deleplanque et al.

Nucl. Phys.

(1975)

A. Faessler et al.

Phys. Lett.

(1972)

Cited by (54)

Nuclear Data Sheets for A=186
2022, Nuclear Data Sheets
Evaluated spectroscopic data and level schemes from radioactive decay and nuclear reaction studies are presented for ¹⁸⁶Lu, ¹⁸⁶Hf, ¹⁸⁶Ta, ¹⁸⁶W, ¹⁸⁶Re, ¹⁸⁶Os, ¹⁸⁶Ir, ¹⁸⁶Pt, ¹⁸⁶Au, ¹⁸⁶Hg, ¹⁸⁶Tl, ¹⁸⁶Pb, ¹⁸⁶Bi, and ¹⁸⁶Po. This evaluation for A=186 supersedes the earlier evaluation 2003Ba44 by C. M. Baglin. Highlights of this evaluation are the following: ¹⁸⁶Re: Revised %ε and %β⁻ branches. New values are almost same as of the earlier ones. Adopted improved level energy for the long-lived (8⁺) isomer at 148.2 keV 5 based on the study reported in 2015Ma60 (¹⁸⁷Re(n, 2nγ)) compared to 149 keV 7 in previous evaluation (2003Ba44). ¹⁸⁶Hg: Discrepancies in the level schemes between 1992Po01 and 1993Ma02 remain to resolve experimentally, arise primarily due to the assigned multipolarity of the ≈607 keV γ transition between the 1228 keV bandhead and the 2⁺ 621 keV level. See general comments in Adopted Levels, Gammas dataset. ¹⁸⁶Tl: From α decay studies, 2020St11 propose spin-parity (2⁻) for the g.s. and (7⁺) for the excited level at 0.0+x of level energy of 77 keV 56. From mass measurements, 2014Bo26 propose the (7⁻) level energy of 20 keV 40 earlier.
Electric monopole transitions in nuclei
2022, Progress in Particle and Nuclear Physics
Electric monopole, $E 0$ transitions in nuclei are reviewed. Values for $ρ^{2} (E 0) \times 1 0^{3}$ , $X (E 0 / E 2)$ and $q_{K}^{2} (E 0 / E 2)$ are tabulated. Particular attention is paid to a complete re-evaluation of all reported values starting from raw input data, i.e. none of the adopted values are taken from the literature without evaluation. Values for $J \to J$ transitions for $J = 0$ , $J = 2$ , and some selected $J = 4$ transitions are given. The $2 \to 2$ transitions involve evaluation of $δ (E 2 / M 1)$ mixing ratios. These were usually assessed from values given in ENSDF. Asymmetric uncertainties and multiple sources of error are handled using up-to-date, Monte Carlo-based procedures. All conversion coefficients and electronic factors are taken from the latest tabulations. As a second major component of the review, a detailed illustration of the association of $E 0$ transition strengths with the manifestation of shape coexistence in nuclei is made. This demonstrates that large $E 0$ transition strengths are a strong indication of the presence of shape coexistence in nuclei. In many cases this is shown to be directly corroborated by $B (E 2)$ data. Some details of experimental techniques behind the input data are given. The connection between $E 0$ transition strengths and mean-square charge radii, isotope and isomer shifts is sketched.
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.
Electric monopole transitions between 0+ states for nuclei throughout the periodic table
2005, Atomic Data and Nuclear Data Tables
Adopted spectroscopic information on $0_{i}^{+} \to 0_{f}^{+}$ pure E0 transitions has been deduced by critical evaluation of the available experimental data for all even–even nuclei ranging from $^{4}_{2} {He}_{2}$ to $^{250}_{98} {Cf}_{152}$ . Values of $q_{K}^{2} (E 0 / E 2)$ , the ratio of the K-conversion electron intensity of the $0_{i}^{+} \to 0_{f}^{+}$ , E0 transition to that of the $0_{i}^{+} \to 2_{1}^{+}$ , E2 transition, have been determined. This procedure, together with the most recent theoretical coefficients for internal conversion and electron–positron pair creation, as well as electronic factors, produced a large number of new X(E0/E2) values, defined as the dimensionless ratio of the absolute B(E0) and B(E2) transition rates. The squared value of the monopole transition strength, ρ²(E0), has been deduced using the best available 0⁺-level half-lives and branching ratios.
Nuclear data sheets for A = 186
2003, Nuclear Data Sheets
Nuclear structure data pertaining to all nuclei with mass number A=186 have been evaluated, and incorporated into the ENSDF database. This evaluation for A=186 includes data available by 4 April 2003. It supersedes the previous publication (C. Baglin, Nuclear Data Sheets 82, 1 (1997) (literature cutoff date 31 August 1997)) and subsequent revisions of Hf and Ta (literature cutoff date 26 November 1998) and W (literature cutoff date 17 February 1999).
Low-spin non-yrast states in light tungsten isotopes and the evolution of shape coexistence
2001, Nuclear Physics A
Excited states in ¹⁷⁰W, ¹⁷²W, ¹⁷⁴W, ¹⁷⁶W and ¹⁷⁸W have been populated in the $β$ -decay of ^170–178Re isotopes and studied using $γ$ -ray singles and coincidence techniques, utilising the high efficiency of a Compton-suppressed array, and conversion electron systems. Many new states at low excitation energies have been identified, complementing the level schemes previously established from in-beam studies. A large body of data on decay properties, spins and parities, and relative E2 and E0 matrix elements has been obtained. The properties of the $K^{π} =0^{+}$ (“quasi”- $β$ ) and the $K^{π} =2^{+}$ (“quasi”- $γ$ ) bands are compared with similar bands observed in light osmium, platinum and mercury isotopes, where shape coexistence has been established at low spin.

View all citing articles on Scopus

View full text

Article preview

Nuclear Physics A

Abstract

References (33)

Nucl. Phys.

Nucl. Phys.

Nucl. Phys.

Phys. Lett.

Phys. Lett.

Nucl. Phys.

Phys. Rev. Lett.

Phys. Rev. Lett.

Phys. Lett.

The Orsay on-line separator ISOCELE

Rev. Phys. Appl.

UCRL 19452

IPNO 75-03

Phys. Rev. Lett.

Nucl. Data Tables

Ph.D. thesis

Compt. Rend.

J. de Phys.

J. de Phys. Lett.

Nucl. Phys.

Phys. Lett.

Cited by (54)

Nuclear Data Sheets for A=186

Electric monopole transitions in nuclei

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

Electric monopole transitions between 0<sup>+</sup> states for nuclei throughout the periodic table

Nuclear data sheets for A = 186

Low-spin non-yrast states in light tungsten isotopes and the evolution of shape coexistence