Isomeric states in odd-f isotopes of Sm, Gd, Dy and Er ascribed to the 112−|505| nilsson configuration

doi:10.1016/0375-9474(70)90562-2

Nuclear Physics A

Volume 143, Issue 2, 16 March 1970, Pages 255-276

https://doi.org/10.1016/0375-9474(70)90562-2 Get rights and content

Abstract

Experimental results on previously unreported micro- and millisecond isomers in odd-N isotopes of Sm, Gd, Dy and Er are presented. The activities are produced by pulsed beams of d, α or ³He. The isomeric levels are in all cases ascribed to the $112$ ⁻ [505] orbital, and in several cases a decay scheme has been proposed.

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Cited by (61)

Nuclear Data Sheets for A=153
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The experimental results published before August 2020 from the various reaction and decay studies leading to nuclides of Z=55 to Z=72, ¹⁵³Ba, ¹⁵³La, ¹⁵³Ce, ¹⁵³Pr, ¹⁵³Nd, ¹⁵³Pm, ¹⁵³Sm, ¹⁵³Eu, ¹⁵³Gd, ¹⁵³Tb, ¹⁵³Dy, ¹⁵³Ho, ¹⁵³Er, ¹⁵³Tm, ¹⁵³Yb, ¹⁵³Lu, ¹⁵³Hf in the A=153 mass chain have been reviewed. These data are summarized and presented, together with adopted level schemes and properties. This work is intended to supersede the previous evaluation of the A=153 nuclides by R.G. Helmer (2006He06), which was published in Nuclear Data Sheets 107, 507 (2006).
Nuclear Data Sheets for A = 157
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Nuclear Data Sheets for A = 129
2014, Nuclear Data Sheets
The experimental nuclear spectroscopic data for known nuclides of mass number 129 (Ag, Cd, In, Sn, Sb, Te, I, Xe, Cs, Ba, La, Ce, Pr, Nd, Pm, Sm) have been evaluated and presented together with adopted properties for levels and γ rays. This evaluation represents a revision of the previous one 18 years ago by Y. Tendow (1996Te01). Extensive new data have become available for many nuclides in the intervening years, although, no data are available for excited states in ¹²⁹Pm and ¹²⁹Sm, and for ¹²⁹Ag and ¹²⁹Cd, only limited information is available for the g.s. and isomers. The decay schemes of ¹²⁹Ag, ¹²⁹Pm and ¹²⁹Sm are unknown, and those for ¹²⁹Cd, ¹²⁹In, ¹²⁹Ce, ¹²⁹Pr and ¹²⁹Nd are incomplete. Many γ rays and extended level schemes have been reported for the ground state and isomer decays of ¹²⁹Ba to ¹²⁹Cs, yet the adopted set of intensities in this evaluation originate from a brief paper in an annual laboratory report. There remain several unplaced gamma rays, coupled with ambiguity about division of intensities amongst the two activities of ¹²⁹Ba with nearly the same half-lives. Isomerism is expected in ¹²⁹Pr, but there is no confirmed identification. Low-lying level structure in ¹²⁹Nd, including identification of a possible third long-lived isomer in this nuclide, remains uncertain.
The spin-parity assignments of (5/2+) for the ground state and (7/2−) for an isomer at 107.6 keV in ¹²⁹Ce are assigned based on strong support from systematics and band configurations, yet this result is in contradiction with the quadrupole interaction hyperfine structure measurement which favors 9/2− over 7/2− for the isomer, consequently 7/2+ for the ground state. Direct measurements of spins of ground state and isomer of ¹²⁹Ce are needed to settle this issue. Confirmed spins and parities of the ground state and isomer of ¹²⁹La are also lacking. Assignments in this work are mainly based on systematics of $h_{11 / 2}$ decoupled structures. A direct measurement of ground state spin of ¹²⁹La will also be desirable.
Recommended data presented in this work supersede those in previous NDS evaluations of A=129 nuclides published by 1996Te01, 1983Ha46 and 1972Ho55.
Nuclear Data Sheets for A = 161
2011, Nuclear Data Sheets
The experimental results from the various reaction and radioactive decay studies leading to nuclides in the A=161 mass chain have been reviewed. Nuclides ranging from Sm (Z=62) through Os (Z=76) are included, with Os being a new entry based on a recently reported study. These data are summarized and presented, together with adopted level schemes and properties. This work supersedes the previous evaluation (2000Re14) of the data on these nuclides.
A double vacuum, configuration dependent pairing and lack of β-vibrations in transitional nuclei: Band structure of N = 88 to N = 91 Nuclei
2010, Nuclear Physics A
We have used the AFRODITE γ-ray spectrometer to measure yrare structures in ^152,154,155Gd using (α,xn) reactions. The measurements on ^152,154Gd have shown that there is no convincing evidence that the lowest excited $0_{2}^{+}$ states are β-vibrations based on the $0_{1}^{+}$ ground state. Rather these levels may be regarded as a “second vacuum” each with its own γ and octupole vibrations. This is confirmed by the blocking of the coupling of this core $0_{2}^{+}$ state in ¹⁵⁴Gd to the $[505] 11 / 2^{-}$ single-particle quasi-neutron orbital in ¹⁵⁵Gd. The coupling of this orbital to the $2^{+}$ γ-vibration is observed since this coupling is not Pauli-blocked.
Nuclear Data Sheets for A = 151
2009, Nuclear Data Sheets
Nuclear spectroscopic information for known nuclides of mass number 151 (Cs,Ba,La,Ce,Pr,Nd,Pm,Sm,Eu, Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu) with Z = 55 to 71 and N = 96 to 80 have been evaluated and presented together with adopted energies and Jπ of levels in these nuclei. No excited state data are yet available for ¹⁵¹Cs, ¹⁵¹Ba and ¹⁵¹La; only the isotopic identification has been reported, without information about their half-lives or decay modes. The ¹⁵¹Hf nuclide has not yet been identified. The radioactive decays of ¹⁵¹Ce, ¹⁵¹Ho (35.2-s and 47.2-s activities), ¹⁵¹Er (23.5-s and 0.58-s activities), ¹⁵¹Yb (two activities of about the same half-life) are not well established. For the decay of ¹⁵¹Lu, only the half-life is known.
Superdeformed structures are well established in ¹⁵¹Dy and ¹⁵¹Tb with a total of five SD bands in ¹⁵¹Dy and ten SD bands in ¹⁵¹Tb. In ¹⁵¹Gd, six SD bands have been tentatively assigned. In ¹⁵¹Tb, yrast SD-1 band has now (2008Ro23) been linked to normal-deformed structures through two well-defined high-energy γ transitions and possibly four other tentative γ rays.
This evaluation represents a revision of earlier (1997Si03,1988Si15,1976Ha35) evaluations of A = 151.

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Isomeric states in odd-f isotopes of Sm, Gd, Dy and Er ascribed to the 112−|505| nilsson configuration

Abstract

Nucl. Phys.

Nucl. Phys.

Nucl. Phys.

Nucl. Phys.

Nucl. Phys.

Nucl. Data

Phys. Lett.

Nucl. Phys.

Nucl. Phys.

Nucl. Phys.

Nucl. Phys.

Mat. Fys. Medd. Dan. Vid. Selsk.

Mat. Fys. Medd. Dan. Vid. Selsk.

Table of isotopes

Mat. Fys. Medd. Dan. Vid. Selsk.

Annual Report from Research Institute for Physics

Isomeric states in odd-f isotopes of Sm, Gd, Dy and Er ascribed to the $112$ ⁻|505| nilsson configuration