No abstract available

[en] The 1965 version of the Nuclear Data Sheets was revised according to experimental data received prior to May 1974, including approximately 120 papers. Data are presented for ten nuclei (Er, Tm, Yb, Lu, Hf, Ta, W, Re, Os, and Ir). Only alpha decay data are available for Os and Ir, only the half-life is known for Re, and no level scheme is known for Er. The Er(49.3 h) decay scheme is well established and provides the only data available on the Tm level scheme (16 levels, 9 J/sup π/ values, and 3 proposed rotational bands). The Tm(63.6 h), Lu(6.7 d), and /sup m/Yb(3.6 μs) decay schemes are compared, and suggested changes and discrepancies in the Yb level scheme are noted. These data as well as considerable reaction data and γ-multipolarity data establish the Yb level scheme, including 128 levels (45 J/sup π/ values) and 14 proposed rotational bands. Data on the Lu level scheme are available from Hf(1.87 y) decay and include 10 levels with J/sup π/ assignments. Two isomers (3.7 m and 440 μs) and their decays are also known for Lu. The Hf level scheme has been studied by Ta(36.8 m) decay and (xnγ) reactions and includes 34 levels (17 J/sup π/ values) with 3 proposed rotational bands. A preliminary decay scheme for W(6.7 m) suggests 4 levels and J/sup π/ assignments in Ta. (xnγ) reactions in W have established the ground-state band up to J/sup π/ = 14⁺. (U.S.)

[en] 'Identical bands', i.e., bands with similar transition energies, have been found in neighbouring odd and doubly-odd ^171-174Ta. This similarity is interpreted here as due to fortuitous compensations between different transverse and collective angular momenta and moments of inertia. (author). 3 refs., 1 fig., 1 tab

[en] The on-line separation of Hf and Ta produced by the reactions of ¹⁶³Dy(¹²C, xn) Hf and ¹⁶⁵Ho(¹²C, xn) Ta respectively have been carried out and the separating conditions have been discussed. From the experimental results one can see that it is possible to separate elements 104 and 105 with a similar thermochromatographic method

[en] Nuclear spectroscopic data for known nuclides of mass number 172 (Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au) have been evaluated and presented together with adopted energies and Jπ of levels in these nuclei. No data are yet available for excited states in ¹⁷²Ho, ¹⁷²Pt, ¹⁷²Au. This evaluation represents a revision of earlier Nuclear Data Sheets for A=172. No experimental data are available for ¹⁷²Gd, ¹⁷²Dy, ¹⁷²Hg, and ¹⁷²Pb. Structure calculations related to deformation, moments, superdeformed shapes, and intruder levels have been reported for Gd, Dy, Hg, and for Pb

No abstract available

[en] The experimental has been performed with a view to studying complete and incomplete fusion in ¹⁴N + ¹⁶³D_y system below 7 MeV/nucleon. The excitation functions for several reactions have been measured using the activation technique and compared with the theoretical predictions based on statistical models. The codes ALICE-91 and CASCADE used earlier for the analysis of excitation functions in case of ¹²C + ¹⁶⁵H₀ system have been used here also with the same set of input parameters. It has been observed that the theoretical calculations do not match with the experimental excitation functions well but the overall shape of the excitation function is reproduced satisfactorily. The composite nucleus (¹⁷⁷T_a) formed in this (¹⁴N + ¹⁶³D_y) case is the same as the one formed in ¹²C + ¹⁶⁵H₀ system studied earlier. Measured excitation functions for the same decay channels in the two cases (i.e. ¹²C + ¹⁶⁵H₀ and ¹⁴N + ¹⁶³D_y) have been compared. A comparison of these excitation functions indicates relatively smaller values of cross sections for all reaction in ¹⁴N + ¹⁶³D_y, in general. Moreover, it has been found that in contrast to the ¹²C induced reaction, where a substantial part of the reaction cross section goes through incomplete fusion, there is nocontribution from incomplete fusion to the reaction cross section in the case of ¹⁴N induced reactions at theses energies. This may indicate that ¹²C undergoes breakup into ⁴H_e and ⁸B_e while ¹⁴N does not undergo breakup below 7 MeV/nucleon. (author)

[en] Several rotational structures have been identified in ¹⁷²Ta. The doubly decoupled π1/2^-[541]xν1/2^-[521] band has been followed beyond the first backbend and a crossing frequency has been extracted which is almost the average between the values found for the participating orbitals in neighboring odd mass nuclei. Striking additivity properties concerning both deviations of inertia parameters and alignments are shown to be a systematic feature of these structures. These results may be at variance with earlier assertions on the deformation driving tendency of the πh_9/2 orbital and with the exclusive νi²_13/2 character of the first band crossing. (orig.)

[en] The short-lived isotopes of W and their descendants have been isolated from from the nuclear reaction products arising in the bombardment of samarium target with ²⁴Mg ions at the U-400 cyclotron of JINR-Dubna. Chemical separations were performed using previously elaborated fast and continuous ion exchange method. In the similar way were isolated products of ²³⁵U fission, obtained at the microtron MT-25 during irradiation of ²³⁵U with photo-neutrons. (authors). 1 fig., 3 refs

[en] The decays of ^168-174W were observed in the reactions of ³⁶Ar and ⁴⁰Ar beams with enriched targets of ¹³⁶BaF₂ and ¹³⁸BaF₂. The measured half-lives are 53(2) s, 76(6) s, 2.42(4) min, 2.38(4) min, 6.6(9) min, 6.3(4) min, and 35.3(5) min, respectively. Decay schemes were derived from the γ- and X-ray coincidence data. Spin assignments of ground- and excited states are discussed within experimental level systematics and compared with the results of microscopic-macroscopic model calculations. Excitation energies of modeled one-quasiparticle states were found in reasonable agreement with the experimental data. Allowed unhindered beta decay from the 5/2^-[523] to the 7/2^-[523] configuration was identified in ¹⁷¹W and this transition is also proposed for the decays of the even-even isotopes ^168,170W. (orig.)