[en] The structures of two observed high-spin rotational bands in the doubly-odd nucleus ¹⁶⁸Ta are investigated using the cranked shell model with pairing correlations treated by a particle-number conserving method, in which the blocking effects are taken into account exactly. The experimental moments of inertia and alignments are reproduced very well by the calculations, which confirms the configuration assignments for these two bands in previous works. The backbending and upbending mechanisms in these two bands are analyzed in detail by calculating the occupation probabilities of each orbital close to the Fermi surface and the contributions of each orbital to the total angular momentum alignments. The investigation shows that the level crossings in the first backbending is the neutron $i_{13/2}$ crossing and the in second upbending is the proton $h_{11/2}$ crossing.

[en] The study of nuclear structure, especially at high spins, has been a fascinating research area in nuclear physics. In the case of nuclei with A=150-190 and A > 220, they are inherently deformed. Discussed in the present work is the Projected Shell Model (PSM) theoretical studies of Tantalum isotopes which has been carried out at high spin regime. Nuclei at high spins exhibit interesting properties such as shape changes, back-bending, band-crossing etc

No abstract available

[en] We present results from two methods of direct mass measurements of relativistic exotic nuclei stored in the storage ring ESR. Schottky Mass Spectrometry (SMS) with electron-cooled ions is well suited for long-lived nuclei (T_1/2≥10 s), and the Isochronous mass measurements (IMS) for hot fragments (T_1/2≥1 μs). In addition, SMS provides information on nuclear lifetime for bare and highly ionized atoms

[en] Short communication

[en] γ-rays from the decay of ¹⁶⁸Ta, Tsub(1/2) = 2.44 +- 0.35 min., have been studied singly and in two-parameter coincidences. Spectrum multiscaling spectroscopy provided accurate half-life information. Sources of ¹⁶⁸Ta were prepared by the thermalization and transport of recoil products from the ¹⁵⁹Tb(¹⁶O, 7n)¹⁶⁸Ta reaction by means of a helium-jet system. Rotational levels of the ground-state, β- and γ-vibrational bands of ¹⁶⁸Hf have been observed and a decay scheme with deduced branching ratios and log ft values is proposed. (author)

[en] High-spin states in the odd-odd nucleus ¹⁶⁸Ta have been populated in the ¹²⁰Sn(⁵¹V,3n) reaction. Two multi-quasiparticle structures have been extended significantly from spin ∼20(ℎ/2π) to above 40(ℎ/2π). As a result, the first rotational alignment has been fully delineated and a second band crossing has been observed for the first time in this nucleus. Configurations for these strongly coupled rotational bands are proposed based on signature splitting, B(M1)/B(E2) ratio information, and observed rotation-alignment behavior. Properties of the observed bands in ¹⁶⁸Ta are compared to related structures in the neighboring odd-Z, odd-N, and odd-odd nuclei and are discussed within the framework of the cranked shell model.

No abstract available

[en] The products of heavy ion reactions induced by bombarding ¹⁵⁴Gd with 149 MeV and 160 MeV ²⁰Ne ions were chemically separated by cation exchange and investigated by γ-spectrometry. In the W-fraction the new isotopes ¹⁶⁸W and ¹⁶⁹W were identified. Their half-lives have been found to be 49+-7 s and 55+-10 s, respectively. The most intensive γ-lines have been assigned to these isotopes

[en] Progress is reported in both theoretical and experimental nuclear physics. Experimental work has focused on the nuclear resonance spectroscopy of odd-odd deformed nuclei such as Tm-168, Lu-174, and Lu-176. In addition, the levels in Er-169 have been studied and detailed Coriolis coupling calculations have been done. Theoretical work has included the study of new collective modes so far not experimentally identified by presumably capable of being identified, rotational energy systematics using the generator coordinate method with particular emphasis on transitional nuclei, the relationship between the cluster model and the shell model as applied to the spectroscopy of Oxygen-16, and the importance of the deformed spin orbit potential for Nilsson model calculations. Additional research has concerned metal-metal stretching frequencies in the polymetallic carbonyls and on the crystal structure and the nuclear resonance spectroscopy of dirhenium decacarbonyl