g-Factors of high-spin isomers in 194Hg and 196Hg

doi:10.1016/0370-2693(80)90581-X

Physics Letters B

Volume 97, Issue 2, 1 December 1980, Pages 197-199

https://doi.org/10.1016/0370-2693(80)90581-X Get rights and content

Abstract

The g-factors of the 10⁺ isomeric states in ¹⁹⁴Hg and ¹⁹⁶Hg have been measured using the in beam IPAD method. The results $g(^{194} Hg) = −0.24(4)$ and $g(^{196} Hg) = −0.18(9)$ are in agreement with the value expected for an ( $i_{1} 32$ ⁻²) neutron satructure and clearly contradict the previous assignment as ( $h_{112}^{−2}$ ) proton configurations. Cranking model calculations show that the neutron excitation energies in the rotating frame agree satisfactorily with the experimental energies and that the proton excitations are expected ≈2 MeV above the experimental yrast line

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Cited by (34)

Nuclear Data Sheets for A=194
2021, Nuclear Data Sheets
Experimental nuclear structure and decay data are evaluated for all of 14 known nuclides of mass 194 (Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, Po, At, Rn). Detailed evaluated spectroscopic information is presented for each reaction and decay experiment, and by combining all the available data, recommended values are provided for energies, spins and parities and half-lives of levels, together with energies, branching ratios and multipolarities of gamma radiations from the levels, and characteristics of beta and alpha radiations in radioactive decays. No excited states have yet been identified in ¹⁹⁴Ta, ¹⁹⁴W, and ¹⁹⁴Rn. Only limited spectroscopic data are available for ¹⁹⁴Re, with a 45−μs isomer identified, but its absolute energy yet to be determined. Only two levels at unknown absolute energies are reported for ¹⁹⁴At, both of which are isomeric but neither can be unambiguously identified as the ground state. Data are scarce for ¹⁹⁴Os, ¹⁹⁴Bi and ¹⁹⁴Po, while ¹⁹⁴Pt, ¹⁹⁴Au, ¹⁹⁴Hg, ¹⁹⁴Tl and ¹⁹⁴Pb are well studied through decays and reactions. For ¹⁹⁴Ir, although a major (n, γ), E=thermal study and two particle-transfer studies provide large amounts of spectral data, still several problematic issues are found in the assignment of multipolarities for the secondary gamma transitions in the (n, γ) study by 2008Ba25, 1998Ba85 and 1998Ba42, all from the same group. Some issues have been resolved by the evaluators, but we suggest that further experimental work is needed on ¹⁹⁴Ir structure to resolve standing issues, and verify the conclusions made by 2008Ba25. Our attempt to contact the prime authors of the 2008Ba25 paper was not successful. The present work supersedes all the earlier evaluations of A=194 nuclides by 2006Si17, 1996Br26, 1989Si01 and 1972Au11.
Nuclear Data Sheets for A = 196
2007, Nuclear Data Sheets
The 1998 version of nuclear data sheets for A = 196 has been revised and updated on the basis of the experimental results from various decay and reaction studies before January 2006. The experimental data for all known nuclei of A = 196 (Os,Ir,Pt,Au,Hg, Tl,Pb,Bi,Po,At,Rn) have been reevaluated. The experimental methods, references,Jπ arguments,and necessary comments are given in the text. Summary band structure drawings and level schemes from both radioactive decay and reaction studies are presented. Also of special interest are the new identification of superdeformed bands in ¹⁹⁶Pb and ¹⁹⁶Bi.
Nuclear Data Sheets for A = 194
2006, Nuclear Data Sheets
Nuclear spectroscopic information for known nuclides of mass number 194 (Re,Os,Ir,Pt,Au,Hg,Tl,Pb,Bi, Po,At) with Z = 75 to 85 and N = 119 to 109 have been evaluated and presented together with adopted energies and Jπ of levels in these nuclei. No excited state data are yet available for ¹⁹⁴Re and ¹⁹⁴At. Many superdeformed structures are known in A = 194: three SD bands in ¹⁹⁴Hg, two of which are connected to the normal-deformed structures; six SD bands in ¹⁹⁴Tl; and three SD bands in ¹⁹⁴Pb, one of which is connected to the normal-deformed structure. In addition four magnetic-rotational (MR) dipole bands are known in ¹⁹⁴Pb together with many other dipole bands which are probable multi-quasiparticle structures. This evaluation supersedes previous full evaluations of A = 194 published by 1996Br26, 1989Si01, 1977Ha46 and 1972Au11.
Nuclear g factors and structure of high-spin isomers in <sup>190,192,194</sup>Pt and <sup>196,198</sup>Hg
2006, Nuclear Physics A
The integral perturbed angular distribution (IPAD) method in an external magnetic field has been used to measure the g factors of isomers in the ^190,192,194Pt and ^196,198Hg nuclei, populated in the ( $α, 2 n$ )-reaction. The results are as follows: ¹⁹⁰Pt, $g (12^{+}) = - 0.17 (12)$ , $g (10^{-}) = - 0.0016 (36)$ , $g (7^{-}) = + 0.62 (9)$ ; ¹⁹²Pt, $g (12^{+}) = - 0.18 (9)$ , $g (10^{-}) = - 0.0012 (10)$ , $g (7^{-}) = 0.48 (12)$ ; ¹⁹⁴Pt, $g (12^{+}, new assignment) = - 0.17 (7)$ , $g (7^{-}) = + 0.26 (8)$ ; ¹⁹⁶Hg, $g (12^{+} and 10^{+}) = - 0.19 (6)$ , $g (7^{-}) = - 0.030 (17)$ ; ¹⁹⁸Hg, $g (12^{+} and 10^{+}) = - 0.18 (8)$ , $g (7^{-}) = - 0.033 (14)$ . The intrinsic structure of the isomers is discussed. The 12⁺ states have the rotational-aligned $(ν i_{13 / 2}^{−2})$ structure. The missing rotation-aligned $(ν i_{13 / 2}^{−2}) 12^{+}$ state is suggested to be isomeric in ¹⁹⁴Pt (instead of the 10⁺ state) and to which the $g = - 0.17 (6)$ value has to be attributed. From the g factors of the 10⁻ states in ¹⁹⁰Pt and ¹⁹²Pt, which have the configuration $ν 9 / 2^{-} [505] \otimes ν 11 / 2^{+} [615]$ , the anomalous $g_{l}$ -factor for neutrons has been derived as $δ g_{l} = - 0.028 (6)$ . The trend from negative g factors of the 7⁻ states in the ^196,198Hg nuclei to positive values for the corresponding states in the ^190,192,194Pt nuclei indicates a change in the intrinsic structure of the lowest negative-parity bands, from mainly $(ν i_{13 / 2}^{−2})$ in Hg to mainly $(π h_{11 / 2}^{−2})$ in Pt.
Nuclear data sheets for a = 196
1998, Nuclear Data Sheets
The 1995 version of nuclear data sheets for A=196 has been revised. The experimental data for all known nuclei of A=196 (Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, Po, At, Rn) have been reevaluated. Summary band structure drawings and level schemes from both radioactive decay and reaction studies are presented. Associated spectroscopic data and adopted properties for levels and γ rays are given in tables. Also of special interest are the new identification of a superdeformed band and of a two-particle-two-hole-intruder state in¹⁹⁶Pb.
Nuclear data sheets for A = 194
1996, Nuclear Data Sheets
Abstract:Experimental data pertaining to all nuclei with mass A = 194 were evaluated. Level schemes from both radioactive decay and reaction studies are presented, along with associated tables of experimental data and adopted properties for levels and γ rays. The literature cutoff date for this revision is September 30, 1996. This revision replaces 89SiO1. Extensive high-spin experiments using large gamma-detector arrays have revealed superdeformed structures in¹⁹⁴Hg (three SD bands: Yrast and pair of excited signature partners),¹⁹⁴Tl (six SD bands: Three pairs of signature partners), and¹⁹⁴Pb (three SD bands: Yrast and pair of excited signature partners). For yrast bands (SD-1) in¹⁹⁴Hg and¹⁹⁴Pb, connecting transitions between the SD band and normal bands have recently (96Kh04, 96Lo12,96Br07) been reported. Several dipole (oblate) bands in¹⁹⁴Pb, some based on high-K (oblate) states have been reported from similar in-beam γ-ray experiments. New γγ coincidence measurements (93Ko59, 94KoZQ) using the¹⁹³Ir(n,γ) reaction helped to place several transitions in the level scheme and established the 31.85-ms¹⁹⁴Ir isomer at 147.078 KeV 5. Results from the first study of the¹⁹³Ir(d,p) reaction (94Ga30) agree with those from (n,γ). Unpublished (95TeZZ) γγ coincidence results (using HERA, an array of 20 intrinsic germanium detectors) revealed a new level in¹⁹⁴Pt at 1737.4 KeV. It also provided correct placement in the decay scheme for many γ rays from¹⁹⁴Au ϵ decay. Recent measurements (92Hu04) of the α-decay chain²⁰²Fr–¹⁹⁶At–¹⁹⁴Bi confirm the existence of¹⁹⁴Bi isomers, and show population to previously unknown levels at 218 and 396 KeV in¹⁹⁴Bi.Cutoff Date:All data received by September 30, 1996 were evaluated.General Policies and Organization of Material:See the January issue of Nuclear Data Sheets.Acknowledgments:Evaluators wish to thank R.R.P. Teixeira (95TeZZ) for making available their unpublished data on¹⁹⁴Au ϵ decay.General Comments:The analysis of γ-ray data is described in detail in 86BrZQ. The γ-ray energies given by various authors were fit to a level scheme for each data set through a weighted least-squares analysis. The scales for the corresponding intensities, which were assumed to be linearly related, were adjusted using the methods of Tepel (80TeZW) and Lederer (92LeZJ). Uncertainties of absolute γ-ray intensities were determined using the method of Browne (86Br21).

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¹: Permanent address: Tate Institute of Fundamental Research, Bombay, India.

²: HTNF fellow 1980, on leave from Institute of Physics, University of Oslo, Oslo, Norway.

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g-Factors of high-spin isomers in 194Hg and 196Hg

Abstract

Nucl. Phys.

Nucl. Phys.

Nucl. Phys.

Nucl. Phys.

Nucl. Phys.

g-Factors of high-spin isomers in ¹⁹⁴Hg and ¹⁹⁶Hg