[en] The products of the heavy ion reactions induced by bombarding ¹⁵¹Eu with 154 MeV and 164 MeV ²⁰Ne ions were assayed by continuous γ-spectrometry. In periodic batch-wise experiments the Ta-fraction was chemically separated and the isotope ¹⁶⁴Ta with a half-life of 20+-5 s was found, emitting 210.6 keV γ-rays. The assignment is based on the measured growth and decay curve of ¹⁶⁴Hf. (author)

[en] The products of the heavy ion reactions induced by bombarding ¹⁵¹Eu with 154 MeV and 164 MeV ²⁰Ne ions were chemically separated and investigated by γ-spectrometry. In the Ta fraction of the products ¹⁶⁵Ta was identified, its half-life is 35+-10 s. The most intensive γ-lines have been identified and assigned. (author)

[en] Tantalum 164 to 167, Zirconium 82 to 84 and Strontium 78 have been selectively observed at the ISOCELE-2 on-line mass separator in the TaF₄⁺, ZrF₃ and SrF⁺ compound form. New isotopes have been identified: ¹⁶⁵Ta (31.0 +- 1.5 s), ¹⁶⁴Ta (13.7 +- 0.6 s), ⁸²Zr, (32 +- 5 s) and ⁷⁸Sr (2.5 +- 0.3 mn). (orig.)

[en] Nuclear spectroscopic information for known nuclides of mass number 165 (Eu,Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu,Hf,Ta,W,Re,Os,Ir) with Z = 63 to 77 and N = 102 to 88 have been evaluated and presented together with adopted energies and Jπ of levels in these nuclei. No excited state data are yet available for ¹⁶⁵Eu, ¹⁶⁵Gd and ¹⁶⁵Tb. In ¹⁶⁵Re an isomer is known at about 50 keV; in ¹⁶⁵Os, about 15 gamma rays are known but no level scheme has been proposed; and in ¹⁶⁵Ir, the the ground state has not yet been identified, but an isomeric state at about 180 keV has been established. Fairly rich structures are known for all the other A = 165 nuclides. Triaxial Superdeformed structures are known in ¹⁶⁵Lu (five SD bands). This evaluation supersedes previous full evaluations of A = 165 by 1987Pe01 and 1974Bu29, a midstream evaluation (in update mode) by 1992Pe04 with literature cutoff date of November 1990, and evaluation of ¹⁶⁵Lu nuclide by 1999Si16. Extensive new data have since become available for most of the nuclides of A = 165 and have been included in the current evaluation

[en] Methods were examined for continuous radiochemical separation of short-lived W, Ta, and Hf isotopes obtained in nuclear reactions with heavy ions. Studies were made on the efficiency of radioactive nuclide transport from a cyclotron beam target to the chemical laboratory, using an aerosol stream (N₂ + KCl) followed by filtration and then dissolution of the particulate matter. Conditions were chosen for sequential chemical separation of these periodic-system-adjacent elements. Fast methods were developed capable of a 10-20 sec identification of new, short-lived W, Ta and Hf isotopes

[en] An experimental approach to continuous radiochemical isolation and identification of short-lived isotopes of the elements Hf, Ta and W is described. A multistep procedure is based on transportation of the radioactive nuclides from the cyclotron target to laboratory by an aerosol stream (N₂ + KCl), separation and dissolution of the aerosol particulates, and isolation of the element under study by ion exchange or extraction techniques. Efficiencies of different steps of the complex procedure were measured and optimal conditions are discussed. The inherent processing time down to 10-20 s was achieved. Some new short-lived isotopes of W, Ta and Hf were identified. (orig.)

[en] Multiplicities are compared for ⁴He evaporation in reactions of ⁴⁰Ar and ⁵⁶Fe projectiles (8.5 MeV/u) with sup(nat)Ag and ²³⁸U targets. Coincidence requirements involving fusion-fission and projectile-like fragments have been used to select separate entrance-channel spin zones. Evaporation-like ⁴He emission from the composite nuclei is shown to be large for mean spins J100(h/2π), and to decrease dramatically with increasing spin. Coincidence measurements between two ⁴He particles have also been studied for ⁴⁰Ar+sup(nat)Ag. This requirement is shown to select reactions that lead to evaporation residues and therefore to a zone of relatively low spin. The shapes of the ⁴He spectra provide an interesting probe of the mechanism and also of the thermodynamic properties of hot nuclei. (orig.)