[en] We experimentally investigated the effect of laser intensity on the selective photoionization of ¹⁶⁸Yb isotope. The photoionization scheme used in our experiment consisted of the excitation from the ground state (6s²¹S₀) to the state of 4f¹³6s²6p (7/2, 3/2)₂ through an intermediate state (6s6p ³P₁), followed by the ionization to the autoionization state(52353 cm^-1). For the excitation, two dye lasers (linewidth of 250 MHz) pumped by a high-repetition laser were used. The ionization was achieved by a broadband laser (linewidth of 6 GHz). Using a time-of -flight mass spectrometer, we investigated the ion yield and the selectivity of ¹⁶⁸Yb as a function of the intensity of the second excitation laser. A noble increase in selectivity of ¹⁶⁸Yb isotope was obtained for the case of the optimum intensity of the second laser.

[en] The three-colour three-step three-photon ionization scheme of Yb such as 6¹S₀(0 cm^-1) → 6³P₁(17992.008 cm^-1) → (7/2,3/2)₂4f¹³6_s²6p(35196.98 cm^-1) → A.I.(52353 cm^-1) si chosen to examine the population dynamics of the isotopes consisting of Yb medium. The Bloch equation is numerically solved, where the interacting lasers are supposed to be on-resonant with the transition lines of ¹⁶⁸Yb. The effects of quasi-monochromatic single-mode laser bandwidth and Doppler broadening are investigated. It is revealed that the ionization scheme chosen can be used for a photoionization of ¹⁶⁸ Yb resulting in the selectivity of 100%, but also that the laser beam propagation in a thick medium for ionizing the element can be affected by at least two isotopes of ¹⁷¹Yb and ¹⁷³Yb.

[en] The efficiency of the two photoionization schemes, scheme 1: 4f¹⁴6s²¹S₀ (0 cm^-1) → (555.648 nm) 4f¹⁴6s6p ³P₁^o (17 992.007 cm^-1) → (581.027 nm) 4f¹³6s²6p(7/2, 3/2)₂ (35 196.98 cm^-1) → (582.79 nm) autoionization state (52 353 cm^-1) → Yb⁺ and scheme 2: 4f¹⁴6s²¹S₀ (0 cm^-1) → (398.8 nm) 4f¹⁴6s6p ¹P₁^o(25 068.222 cm^-1) → (<394 nm) Yb⁺ has been studied by a spectral simulation approach for the isotope-selective excitation of the ¹⁶⁸Yb isotope. Isotopic selectivities have been computed for 4f¹⁴6s²¹S₀-4f¹⁴6s6p ³P₁^o (555.648 nm), ³P₁^o-(7/2, 3/2)₂ (581.027 nm) and 4f¹⁴6s²¹S₀-4f¹⁴6s6p ¹P₁^o (398.8 nm) transitions for various laser bandwidths of the excitation lasers. The degree of enrichment of the low-abundant ¹⁶⁸Yb isotope has been computed using the obtained isotopic selectivity values. Results obtained for scheme 1 are in good agreement with the results reported earlier. The abundance of ¹⁶⁸Yb isotope has been computed for various laser linewidths of the excitation laser and Doppler widths for scheme 2. Comparison of the two photoionization schemes for isotope-selective photoionization of the ¹⁶⁸Yb isotope has been made. The present computational method has been examined for computation of degree of enrichment for the photoionization schemes under consideration. (author)

[en] We report in this study some physical and chemical properties of Yb element. Resonance ionization schemes of ¹⁶⁸Yb isotope are also reported. The three concerned suitable wavelengths are reported, in addition to the lifetime of the involved energy states that produce ions. Also some parameters related to the atomic and laser beams such as intensity, bandwidth, and others are reported.(author)

[en] New ΔI = 1 bands with relatively high B(M1)/B(E2) branching ratios were found in Yb isotopes. The [505]11/2^- neutron state from the top of the h_11/2 subshell in most likely involved in the configuration of such bands, since it is the only high-K orbital near the Fermi surface in that mass region. The [505]11/2^- band in ¹⁶⁷Yb, previously known up to I = 19/2 is extended up to I = 35/2. Two new bands, tentatively assigned (h_11/2)^-1 x i_13/2 configuration, one in ¹⁶⁶Yb and another in ¹⁶⁸Yb are observed from the ¹²⁴Sn(⁴⁸Ca,xn) reaction at 225 at 210 MeV. Both bands have constant alignment in the frequency range ℎω = 150 - 350 keV. The new bands are expected to provide good tests of the recently developed tilted cranking formalism

[en] The excitation energy of the lowest I-odd states in ¹⁶⁸Yb is calculated in a wide range of spins I by using the microscopic model suggested earlier by two of the authors. This family of states has close relation to the γ-vibrational states at low spins and to the one-phonon precessional excitations when I is large. The position of states depends strongly on the shape and inertia properties of nuclei. Description of yrast state energies are in good agreement with experiment

[en] Intrinsically radiolabelled nanoparticles have tremendous prospective in offering an easier, faster, stable, and more specific radiolabelling technique in cancer treatment. In this study, intrinsically radiolabelled ¹⁶⁹Yb (t_1/2 = 32d; γavg. = 93 keV) nanoparticles have been developed for potential use in nanoscale brachytherapy. Nanoscale brachytherapy is an emerging field in cancer care because functionalized nanoparticles can be synthesized to match the sizes of tumor vasculature so that optimal therapeutic payloads with minimum leakage away from target sites can be achieved. Ytterbium-169 was produced by irradiation of enriched (~ 10 % in ¹⁶⁸Yb) Yb₂O₃ target at a flux of 1 × 10¹⁴ n.cm^-2.s^-1 for 14 d in the Dhruva reactor. The irradiated target was radiochemically processed and intrinsically radiolabelled gum arabic coated (¹⁶⁹Yb)Yb₂O₃ nanoparticles were synthesized by controlled hydrolysis in aqueous medium for potential application in nanoscale brachytherapy. Nonradioactive gum arabic coated Yb₂O₃ nanoparticles were also synthesized and extensively characterized by various techniques. Overall, we have successfully developed intrinsically radiolabelled gum arabic coated (¹⁶⁹Yb)Yb₂O₃ nanoparticles which shows potential as a cancer theranostic agent in preclinical settings

No abstract available

[en] The excitation of the nucleus in the decay of a mu meson in the K shell of a muonic atom is considered. The probabilities of excitation of the first few 0⁺/sub i/ nuclear states are calculated. Numerical results are given for the nucleus ¹⁶⁸Yb

[en] We report in this study some physical and chemical properties of Yb element. Resonance ionization schemes of ¹⁶⁸Yb isotope are also reported. The three concerned suitable wavelengths are reported, in addition to the lifetime of the involved energy states that produce ions. Also some parameters related to the atomic and laser beams such as intensity, bandwidth, and others are reported