Observation of a multiply ionized plasma with index of refraction greater than one

We present clear experimental evidence showing that the contribution of bound electrons can dominate the index of refraction of laser-created plasmas at soft x-ray wavelengths. We report anomalous fringe shifts in soft x-ray laser interferograms of Al laser-created plasmas. The comparison of measured and simulated interferograms shows that this results from the dominant contribution of low charge ions to the index of refraction. This usually neglected bound electron contribution can affect the propagation of soft x-ray radiation in plasmas and the interferometric diagnostics of plasmas for many elements.     

Dense plasma diagnostics with an amplitude-division soft-x-ray laser interferometer based on diffraction gratings

We report the demonstration of an amplitude-division soft-x-ray interferometer that can be used to generate high-contrast interferograms at the wavelength of any of the saturated soft-x-ray lasers (5.6-46.9 nm) that are available at present. The interferometer, which utilizes grazing-incidence diffraction gratings as beam splitters in a modified Mach-Zehnder configuration, was used in combination with a tabletop 46.9-nm laser to probe a large-scale (~2.7-mm-long) laser-created plasma.     

Quadrupole nuclear interactions on 73As nuclei in a Ge matrix

Large quadrupole interactions produced in Ge by radiation damage following the ⁷²Ge(α, 3n) ⁷³Se reaction are measured by TDPAC at 77 and 300 K. A strong dependence of the quadrupole frequencies with the time intervals after the end of the α irradiation is observed.     

Level structure of 82Rb,studied through the 81Br(α, 3n) reaction

Nuclear states of ⁸²Rb were studied through the ⁸¹Br(α, 3n) reaction at various bombarding energies between 30 and 55 MeV. Excitation functions, γ-ray angular distributions, γ-γ coincidences and γ-time distributions with respect to the beam bursts were determined. Levels at 123.2, 187.7, 233.6, 796.3, 1214.1 keV and tentatively at 1835.5 keV were observed. It was not possible to establish whether the lowest state of the proposed level scheme corresponds to the ground state or to the $\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{= 6.2}\text{h}$ isomeric state. The 45.9 and 64.5 keV γ-rays do not exhibit any measurable lifetime and a limit $\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{≦ 5}\text{ns}$ has been determined. The situation is similar for the 123.2 keV γ-ray, although in this case the presence of a long-lived component cannot be ruled out.     

Multiphoton reactive surfaces using ruthenium(II) photocleavable cages

Photoreactive surfaces derived from a new photocleavable surface modification agent and with photosensitivity in the Vis and IR region are described. A ruthenium(II) caged aminosilane, [Ru(bpy)(2)(PMe(3))(APTS)](PF(6))(2), was synthesized and attached to silica surfaces. Light irradiation removed the cage and generated surface patterns with reactive amine groups. The photosensitivity of this compound under single (460 nm) and two-photon (900) excitation is demonstrated. Functional patterns with site-selective attachment of other molecular species are described.     

Wiman–Valiron Type Inequalities for Entire and Random Entire Functions of Finite Logarithmic Order

Siberian Mathematical Journal -     

On Influence of the Arguments of Coefficients of a Power Series Expansion of an Entire Function on the Growth of the Maximum of Its Modulus

Siberian Mathematical Journal - The following question is discussed: How fast can the maximum of the modulus of one entire function grow in comparison with the maximum of the modulus of another...     

Level structure of 76Br from the 75As(α,3nγ) reaction

Hitherto unknown states of ⁷⁶Br were excited through the (α, 3nγ) reaction on ⁷⁵As at E_α = 30 to 55 MeV. Excitation functions, γ-ray angular distributions, γ-γ coincidences and the γ-ray emission time with respect to the beam bursts were determined. Levels above the 1^? ground state at energies (in keV) with the following spin-parity assignments are proposed: 141.8, 2; 253.7, 3^?; 491.8, 4; 584.9, 5^?; 1016.3, 6. These levels exhibit the energy spacings of a Coriolis-perturbed rotational band and the branching ratios show collective behavior. The comparison of these levels with those of the $\text{5}\text{2}$⁺ ground-state band recently reported in ⁷⁷Kr show that (a) the Coriolis effects are quite similar and (b) the first two excited levels lie very close in energy in both cases. The possibility that these two facts indicate the validity of the rotation aligned coupling scheme in a doubly odd system is discussed.     

Lifetimes and g-factors of the 6− and 7− isomers in 66Ga and 68Ga

The 6^? and 7^? isomeric states in ⁶⁶Ga and ⁶⁸Ga at 1440.9 and 1229.6 keV, respectively, have been populated with the (¹³C, 2np) and (¹⁵N, n2p) reactions on natural Fe. The half-lives of these states have been measured to be $\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{(6}{}^{\mathrm{?}}\text{,}{}^{66}\text{Ga}\text{) = 57.3 ± 1.2}\text{ns}$ and $\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{(7}{}^{\mathrm{?}}\text{,}{}^{68}\text{Ga}\text{) = 64 ± 2}\text{ns}$. Using previous data on the hyperfine field of Ga in Fe, the g-factors of these states have been determined by means of the TDPAD method. The results are $\text{g(6}{}^{\mathrm{?}}\text{,}{}^{66}\text{Ga}\text{) = 0.129 ± 0.003}$ and $\text{g(7}{}^{\mathrm{?}}\text{,}{}^{68}\text{Ga}\text{) = 0.105 ± 0.003}$. These values are in very good agreement with the independent particle model if one assumes the and configurations and uses the empirical proton and neutron g-factors from odd-A neighboring nuclei instead of the Schmidt values. The large disagreements with experiment when Schmidt values are used show that core polarization effects are important in these nuclei.     

Role of ruthenium oxidation states in ligand-to-ligand charge transfer processes

We describe in this paper the properties of [Ru(II/III)(bpy)(2)ClL](+1/+2) and [Ru(II/III)(bpy)(2)L(2)](+2/+3). L = ditolyl-3-pyridylamine (dt3pya) is a redox active ligand related to triarylamines, which is very similar to 3-aminopyridine except for the reversible redox behavior. The monosubstituted complex shows a metal-to-ligand charge-transfer (MLCT) at 502 nm, and reversible waves in acetonitrile at E(0)(Ru(III/II)) = 1.07 V, E(0)(L(+/0)) = 1.46 V (NHE). The disubstituted complex shows an MLCT at 461 nm, a photorelease of dt3pya with quantum yield of 0.11 at 473 nm, and two reversible one-electron overlapped waves at 1.39 V associated with one of the ligands (1.37 V) and Ru(III/II) (1.41 V). Further oxidation of the second ligand at 1.80 V forms a 2,2'-bipiridine derivative, in an irreversible reaction similar to dimerization of triphenylamine to yield tetraphenylbenzidine. In the dioxidized state, the spectroelectrochemistry of the disubstituted complex shows a ligand-to-ligand charge transfer at 1425 nm, with a transition moment of 1.25 ? and an effective two-state coupling of 1200 cm(-1). No charge transfer between ligands was observed when Ru was in a 2+ oxidation state. We propose that a superexchange process would be involved in ligand-metal-ligand charge transfer, when ligands and metals are engaged in complementary π interactions, as in metal-ligand-metal complexes. Best orbital matching occurs when metallic donor fragments are combined with acceptor ligands and vice versa. In our case, Ru(III) bridge (an acceptor) and two dt3pya (donors, one of them being oxidized) made the complex a Robin-Day Class II system, while the Ru(II) bridge (a donor, reduced) was not able to couple two dt3pya (also donors, one oxidized).