[en] Short communication

[en] Short communication. 5 refs

[en] Short communication. 3 refs.,1 tab

[en] Gamma-rays and internal conversion electrons in the decay of 11.6-min ¹⁵²Nd were measured. The radioactive sources were separated from the fission products of ²³⁵U(n,f) with an on-line isotope separator (KUR-ISOL). A precise decay scheme of ¹⁵²Nd involving 35 γ-rays and 12 levels has been established. The 25 γ-rays and 7 levels were observed for the first time. (author)

[en] The Nd isotopes lie in the region of shape phase transition from spherical ("1"4"4","1"4"6Nd) to well deformed ("1"5"4Nd) nuclei. Many experimental and theoretical studies were performed to organise the information about energy level spacings and transition rates of Nd isotopes. In this paper, the nuclear structure of "1"5"2Nd nucleus is studied in the framework of Interacting Boson Model (IBM). The classical limit of the IBM Hamiltonian has been used to generate the PES for the "1"5"2Nd nucleus

[en] For well deformed (even Z even N) nuclei, the ideal rotor formula provides a good approximation for the level energies. But for the shape transitional nuclei this formula or its extensions to two or three terms are inadequate. Various energy formulae, such as the soft rotor formula (SRF), anharmonic vibrator (AHV), Rotation-Vibration Interaction (RVI) formula and Variable Moment of Inertia (VMI) model etc. are in use. All of these are of the form of an expansion in powers of spin I, or its combinations, limited to two or three terms. However, Gupta et al. proposed a single term formula in the form of a power index expression

[en] This study investigated the effects of tubificid worm bioturbation on the lability of phosphorus (P) in microcosm sediments. High-resolution dialysis (HR-Peeper) and two types of diffusive gradients in thin films (DGT) (Zr-oxide DGT and ZrO-Chelex DGT) were used to measure soluble P and Fe, and labile P and Fe at a millimeter spatial scale. The worm bioturbation promoted P release (up to 511% of the control) to the overlying water on the 6th day, but it was reduced compared to the control (up to 171% of the control) from the 22nd day to the 102nd day because of the adsorption by Fe(III) oxyhydroxides. The worm bioturbation reduced the pore water soluble P concentration up to 48% and the DGT-labile P concentration up to 29% of the control from a sediment depth of −10 mm to approximately −130 mm before the 22nd day of incubation due to worm ingestion of sediment particles. Two-dimensional measurements of DGT-labile P also showed a much lower concentration of labile P around the worm burrow. This effect disappeared on the 53rd and 102nd day. However, the soluble P and DGT-labile P decreased again up to 41% and 38%, compared to the control from the sediment depth of −20 mm and −10 mm to approximately −130 mm, respectively, on the 152nd day of incubation due to the adsorption by Fe(III) oxyhydroxides. Soluble Fe(II) and DGT-labile Fe did not show significant changes from the worm bioturbation on the 6th day, but decreased up to 31% and 47% of the control after the 6th day. The results that worm ingestion of sediment particles is a significant driver of soluble and labile P reduction in the sediments before the 22nd day. After that, soluble and labile P reduction was attributed to P adsorption by Fe(III) oxyhydroxides. - Highlights: • High resolution techniques were employed to investigate P release from bioturbation sediments. • Worm bioturbation decreased the concentration of soluble/labile P in sediments before the 22nd day. • Bioturbation effects disappeared on the 53rd and 102nd day and emerged again on the 152nd day. • The P decreased because of ingestion by worm and adsorption by Fe(III) oxyhydroxides. - Tubificid worm bioturbation decreased the lability of P in sediments.

[en] By the development of oxidation method by Kawase et al., the ISOL of the Kyoto University research reactor was improved largely in its efficiency of ion source, consequently, the fission products with mass number more than 150 have become to be taken out strongly. The authors have carried out the nuclear spectroscopy of rare earth nuclei using the ISOL. By the oxidation method, the strong beam of A=152+16 was taken out using the ISOL, and the β-ray and the internal conversion electrons of Nd-152 and the β-ray of its daughter nuclei Pm-151 were measured. Besides, as for the decay from Pr-151 to Nd-151, its Q_β value is expected to be about 4 MeV, but the level from the decay has been reported only up to 880 keV. As for Pr-151, also the detailed decay scheme was made, and the coordination of 59th proton from the decay to Nd-151 was examined. The γ-ray single and the γ-γ coincidence measurements of Pr-147, Pr-151 and Nd-152, the β single and the β-γ coincidence measurements of Pr-151 and Nd-152, and the β-γ delayed coincidence measurement of Pr-147 and Pr-151 were carried out. The combined use of chemical separation method was done. The results are reported. (K.I.)

[en] Short communication

[en] A fast timing βγγ(t) method has been used to measure level lifetimes in ¹⁵²Nd as populated in the β^- decay of ¹⁵²Pr. The following half-lives have been measured: T_1/2=330(14) and 53(10) ps for the 236.7 keV 4₁⁺ and the 484.0 keV 6₁⁺ members of the ground-state band, T_1/2=145(11), 12(7), and 64(56) ps for the 1542.0 keV 2^-, 1600.7 keV 3^-, and the 1683.2 keV 4^- members of the K^π=2^- band, and T_1/2=42(6) and 30(10) ps for the 1827.5 keV 3^- and the 1893.3 keV 4^- members of the K^π=3^- band, respectively. The observed allowed M1 rates and large hindrance factors for the E1 transitions deexciting these bands is discussed in terms of K forbiddenness and the (suggested) dominant two-quasiparticle configurations. Systematics of the octupole vibrational bands in the rare-earth region is examined. The energy minima for the K^π=1^- bands follow a narrow valley along N=94 associated with the two-quasineutron {ν5/2⁺[642]-ν3/2^-[521]} configuration, while minima for the K^π=2^- bands follow narrow valleys at Z=66 and Z=74 associated with the two-quasiproton configurations {π7/2^-[523]-π3/2⁺[411]} and {π9/2^-[514]-π5/2⁺[402]}, respectively. In contrast, the lowering of the K^π=0^- bands near ¹⁴⁶Ba is along both neutron and proton numbers, giving a flat minimum