Measurement of storage time, estimation of ion number and study of absorption line profile in a Paul trap

Europium (Eu⁺) ions were confined in a Paul trap and detected by non-destructive method. Storage time of Eu⁺ ions achieved in vacuum was improved by orders of magnitude employing buffer gas cooling. The experimentally detected signal was fitted to the ion response signal and the total number of ions trapped was estimated. It is found that the peak signal amplitude as well as the product of FWHM and the peak signal amplitude is proportional to the total number of trapped ions. The trapped ion secular frequency was swept at different rates and its effect on the absorption line profile was studied both experimentally and theoretically.     

Correction: Dermatan sulfate in tunicate phylogeny: Order-specific sulfation pattern and the effect of [→4IdoA(2-Sulfate)β-1→3GalNAc(4-Sulfate)β-1→] motifs in dermatan sulfate on heparin cofactor II activity

After the publication of the work entitled "Dermatan sulfate in tunicate phylogeny: Order-specific sulfation pattern and the effect of [→4IdoA(2-Sulfate)β-1→3GalNAc(4-Sulfate)β-1→] motifs in dermatan sulfate on heparin cofactor II activity", by Kozlowski et al., BMC Biochemistry 2011, 12:29, we found that the legends to Figures 2 to 5 contain serious mistakes that compromise the comprehension of the work. This correction article contains the correct text of the legends to Figures 2 to 5.     

High-accuracy calculations of dipole, quadrupole, and octupole electric dynamic polarizabilities and van der Waals coefficients C 6, C 8, and C 10 for alkaline-earth dimers

The static and dynamic electric dipole, quadrupole, and octupole polarizabilities of the alkaline-earth atoms (beryllium, magnesium, calcium, strontium, and barium) in the ground state were calculated. The dynamic polarizabilities obtained were used to calculate the van der Waals coefficients C ₆, C ₈, and C ₁₀ of alkaline-earth metal dimers for the interaction of two like atoms in the ground state. The results are compared with other theoretical and experimental data.     

Combined configuration-superposition and many-particle perturbation calculations for atoms with two valence electrons

A new high-precision method is used to calculate the characteristics of atoms with two valence electrons. An effective Hamiltonian for the valence electrons is formulated by many-particle perturbation theory with respect to the residual interaction of the valence electrons with the core. The configuration-superposition method is then used to find the energy levels of the atom. The application of the combined method to divalent calcium, strontium, barium, and ytterbium atoms shows that the ionization potential is obtained within 0.5% error limits. The precision attained for the first few lowest levels of the energy spectra is significantly higher than is obtained by configuration-superposition calculations alone. Zh. éksp. Teor. Fiz. 111, 838–846 (March 1997)     

High-precision calculationsj of the 3,1 P 1 0 →1 S 0 E1 amplitudes for magnesium, calcium, and strontium

High-precision calculations of the ^3,1 P ₁ ⁰ (ns np→¹ S ₀(ns ²) E1 amplitudes were carried out for magnesium, calcium, and strontium (n=3, 4, and 5, respectively). The following results were obtained for the reduced matrix element 〈¹ P ₁ ⁰ ‖d‖ ¹ S ₀〉 of electric dipole moment operator: 4.03(2) au for Mg, 4.91(7) au for Ca, and 5.28(9) au for Sr. These matrix elements are necessary for calculating the van der Waals coefficients C ₆, which are used in evaluating the atomic scattering lengths. The latter determine the dynamics and stability of the Bose-Einstein condensate.     

Manifestation of nuclear spin dependent P odd electron–nucleon interaction in atomic ytterbium

P odd effects caused by the nuclear spin dependent electron-nucleon interaction are considered. P-odd amplitudes are calculated for ¹S₀ → ³D_1,2 transitions in atomic ytterbium. This revised version was published online in August 2006 with corrections to the Cover Date.