[en] New microsecond isomers in the neutron-deficient isotopes ^189g,190Bi have been identified after in-flight separation by the velocity filter SHIP. The evaporation residues were identified on the basis of delayed recoil- γ/X-ray, recoil- γ/X-ray- α and excitation function measurements. The systematics of the [ π1i _13/2]13/2 ⁺ excited states in the odd-mass Bi nuclei is discussed. (orig.)

[en] Short communication. 2 refs

[en] Nuclear spectroscopic information for known nuclides of mass number 190 (W,Re,Os,Ir,Pt,Au,Hg,Tl,Pb,Bi,Po) has been evaluated and presented together with adopted energies, Jπ, and decay modes of levels in these nuclei. This evaluation supersedes earlier (1990Si09,1982Le22,1973Sc42) Nuclear Data Sheets for A=190

[en] Short note. 3 refs

[en] Detailed α-decay studies of the neutron-deficient isotope ¹⁹⁴At have been performed in the complete fusion reaction ⁵⁶Fe+¹⁴¹Pr→¹⁹⁴At+3n at the velocity filter SHIP. Two α-decaying isomeric states with half-lives of T_1/2(¹⁹⁴At^m1)=310(8) ms and T_1/2(¹⁹⁴At^m2)=253(10) ms were identified in this nucleus. Their complex decays to the states in the daughter nucleus ¹⁹⁰Bi are discussed in the article. We propose that similar to the case of the neighboring ^{191,192,193,195}At isotopes, the oblate-deformed configurations based on the proton 1/2⁺[440] and/or 7/2^-[514] Nilsson orbitals become important in ¹⁹⁴At. A new isomeric state with the half-life of 175(8) ns was observed in ¹⁹⁰Bi.

[en] In-source laser spectroscopy experiments for neutron deficient bismuth isotopes at the 306.77 nm atomic transition were carried out at the IRIS (Investigation of Radioactive Isotopes on Synchrocyclotron) facility of Petersburg Nuclear Physics Institute (PNPI). New data on isotope shifts and hyperfine structure for "1"8"9"–"1"9"8", "2"1"1Bi isotopes and isomers were obtained. The changes in the mean-square charge radii and the magnetic moment values were deduced. Marked deviation from the nearly spherical behavior for ground states of bismuth isotopes at N < 109 is demonstrated, in contrast to the lead and thallium isotopic chains. The big isomer shift between I = 1/2 (intruder) and I = 9/2 (normal) states for odd Bi isotopes (A = 193, 195, 197) was found

[en] Experimental nuclear structure and decay data for nuclides of mass A = 190 have been evaluated. This work supersedes the previous evaluation by M. R. Schmorak, published in Nuclear Data Sheets 9, 401 (1973). Because of the new experimental results which are incorporated, the present evaluation involves a complete revision of the level structure every mass--190 nuclide except ¹⁹⁰Ir. It covers significant new results not included in the recent evaluation by R. E. Doebler and E. Browne (Table of Isotopes, 7th Edition, ed. by C. M. Lederer and V. S. Shirley, p. 1213ff, John Wiley and Sons, Inc. (1978) for the following nuclides and reactions or decay schemes: ¹⁹⁰Os from ¹⁸⁹Os(n, γ) and Coulomb excitation; ¹⁹⁰Pt from (HI,xnγ) reactions and ¹⁹²Pt(p, t); ¹⁹⁰Au from ¹⁹¹Ir(α, 5nγ); ¹⁹⁰Hg from (HI,xnγ) reactions; ¹⁹⁰TI from ¹⁹⁰Pb epsilon-c decay; ¹⁹⁰Pb from ¹⁵⁴Gd(⁴⁰Ar, 4nγ). Of the nuclei readily studied by nuclear reactions, little is presently known of the odd--odd ¹⁹⁰Ir, and there are only sketchy, preliminary data on high--spin states of ¹⁹⁰AU, which is expected to have a low--lying 11-- isomer whose decay has not been observed. A recent measurement of the g--factor for the 24.1--ns isomer in ¹⁹⁰Hg suggests strongly that this state decays by an unobserved transition, whose existence requires confirmation

[en] The α-decay of mass separated ^{190,192,194,196}Bi isotopes has been studied with the LISOL on-line separator. Time sequential α-singles spectra were taken and for ^190,192,194Bi, αXt and αγt coincidences were collected. Transition probabilities of levels in ^186,188,190Tl were measured using a fast timing αγt and αe^-t coincidence set up. The α-decay of ¹⁹⁶Bi and the β-decay of ¹⁹⁰Bi are observed for the first time. In all the Bi nuclei presently studied, unhindered α-decay of Bi starting from the high- (10^-) and low-spin (3⁺) isomer populating intruder-based states in Tl was observed. The exictation energy of these intruder states is comparable with the intruder states in the neighboring odd-even and even-even nuclei. (orig.)

[en] The α-decay of mass-separated Bi isotopes is studied to characterize shell-model intruder states in odd-odd Tl nuclei. By studying both experimentally and theoretically the members of the π 1h_9/2 intruder-ν li_13/2 multiplet, the unperturbed position of the intruder-based multiplet could be extracted. The scaling of intruder-state energies is discussed. (orig.)

[en] Accurate atomic mass measurements of neutron-deficient and neutron-rich nuclides around the doubly-magic ²⁰⁸Pb and of neutron-rich cesium isotopes were performed with the Penning trap mass spectrometer ISOLTRAP at ISOLDE/CERN. The masses of ^145,147Cs, ^181,183Tl, ¹⁸⁶Tl^m, ¹⁸⁷Tl^m, ¹⁹⁶Tl^m, ²⁰⁵Tl, ¹⁹⁷Pb^m, ²⁰⁸Pb, ^190-197Bi, ^209,215,216Bi, ^203,205,229Fr, and ^214,229,230Ra were determined. The obtained relative mass uncertainty in the range of 2x10^-7 to 2x10^-8 is not only required for safe identification of isomeric states but also allows mapping the detailed structure of the mass surface. A mass adjustment procedure was carried out and the results included into the Atomic Mass Evaluation. The resulting separation energies are discussed and the mass spectrometric and laser spectroscopic data are examined for possible correlations