Photoinduced electron transfer involving radical ions in multicomponent solutions

A phenomenological study of a specific radical ion mechanism of formation of metastable products is presented. Energy level diagrams of fullerene C₆₀, tetramethylbenzidine, perylene, and radical ion pairs in toluene and benzonitrile are constructed. The possibility for obtaining fast optical switching and limiting in solutions of C₆₀ fullerene, tetramethylbenzidine, and perylene in toluene is analyzed.     

Quasielastic triton knockout from 6Li and 7Li nuclei by intermediate-energy pions

Quasielastic triton knockout from ⁶Li and ⁷Li nuclei by negative pions with momenta p ₀=0.72 and 0.88 GeV/c was studied in the region of backward pion-triton scattering. The experiment was performed at the Institute of Theoretical and Experimental Physics (ITEP, Moscow) on a 3-m magnetic spectrometer equipped with spark chambers. The momentum distributions of the intranuclear quasitriton motion and the excitation-energy spectra of residual nuclei were obtained.     

Raman scattering from 6Li+ and 7Li+ ions in lithium beta-alumina

Raman bands due to translational modes of ⁶Li⁺ and ⁷Li⁺ ions in beta-alumina were found in the frequency range of 340–410 cm^?1, which is much higher than expected from the corresponding values reported for other alkali-metal ions (20–100 cm^?1). Based on a model calculation, it is believed that the large shifts to higher frequencies are due to deviations of the Li⁺ ions from the mirror plane into “pocket sites” formed by oxygen ions above or below the Beevers-Ross sites     

Optical double resonance polarization spectroscopy of Rydberg states in7Li2

With Doppler-free two-step polarization spectroscopy rovibronic levels of the 5dδ ¹ Δ _g state in⁷Li₂ are excited via selected levels of the intermediateB ¹ Π _u state. Perturbations between the 5dδ ¹ Δ _g and the 4dπ ¹ Π _g states are observed and molecular constants of the deperturbed state are deduced.     

Reaction efficiencies in nucleon channels for 7Li and 9Be nuclei

Reaction cross sections of the radiative capture of nucleons ⁶Li(n, γ)⁷Li, ⁶He(p, γ)⁷Li, and ⁸Li(p, γ)⁹Be in the region of low astrophysical energies are calculated using the dynamic potential cluster model. The results are compared to the available experimental and theoretical data. The yields of these reactions are also calculated, based on the established theoretical results.     

Deuteron inelastic scattering on 6Li and 7Li nuclei within the three-body cluster model

The problem of the deuteron interaction with lithium nuclei,treated as a system of two coupled pointlike clusters,is formulated to calculate the cross sections of the d+Li reaction.The d+Li reaction mechanism is described using the Faddeev theory for the three-body problem of deuteron-nucleus interaction.This theory is slightly extended for calculation of the stripping processes ^6Li(d,p)^7Li,^7Li(d,p)^8 ,^6Li(d,n)^7 Be,and ^7Li(d,n)^8 Be,as well as fragmentation reactions yielding tritium,a-particles,and continuous neutrons and protons in the initial deuteron kineticenergy region Ed=0.5-20 MeV.The phase shifts found for d+^6Li and d+^7Li elastic scattering,as part of the simple optic model with a complex central potential,were used to find the cross sections for the 6^Li(d,yM)^8 and ^7Li(d,yE1)^9 Be radiation captures.The three-body dynamics role is also summarized to demonstrate its significant influence within the d+^7Li system.     

Dynamic polarization of nuclei in a self-organized ensemble of quantum-size n-InP/InGaP islands

Dynamic polarization of ³¹P nuclei is observed in a self-organized system of InP islands grown by metalorganic-hydride epitaxy in an InGaP matrix. The polarized nuclei produce an effective magnetic field which acts on the polarization of the excitonic radiation. Optical detection of the magnetic resonance signal from ³¹P nuclei in the crystal lattice of nanosize InP islands is successfully carried out. Pis’ma Zh. éksp. Teor. Fiz. 68, No. 9, 711–714 (10 November 1998)     

Isovector giant resonances in light nuclei observed by (7Li, 7Be) reaction

Isovector giant resonances were studied with the (⁷Li, ⁷Be) reaction on ¹²C, ²⁴Mg, ²⁷Al, ²⁸Si and ⁴⁸Ti at an incident energy of 150 MeV. Differential cross sections were measured at forward scattering angles including 0°. We observed the octupole resonance at E_x ∽ 16 MeV and the giant dipole resonance at E_x ∽ 20 MeV in all residual nuclei.     

Production of heavy nuclei in the interaction of <Superscript>7</Superscript>Li ions with copper nuclei at an energy of 35 MeV per nucleon

The absolute values of the cross sections for the production of target fragments in the interaction of copper with ⁷Li ions at an energy of 35 MeV per nucleon were measured. The measurements were performed by recording the yields of radioactive nuclear residues with the aid of a semiconductor detector from ultrapure germanium. The charge and isobaric distributions in the mass-number range 22–69 amu were used to deduce the mass yield of reaction products and to calculate the total interaction cross section. The results are presented that were derived from a comparison with data obtained for ¹²C + Cu reactions and with estimates based on theoretical models.     

Dynamical polarization of radioactive nuclei

In order to polarize radioactive nuclei implanted in a highly polarized protonic target, it is proposed to use methods for the dynamical orientation of nuclei. The angular distribution of photons that originate from the cascade beta-gamma decay of the ²²Na(3⁺) state in a strong magnetic field is calculated. It is shown that, if the populations of Zeeman magnetic sublevels obey the Boltzmann distribution, the angular distribution of emitted photons is independent of the sign of spin temperature; at the same time, the tensor polarization of quadrupole nuclei occurring in the intrinsic field of a crystal causes a strong dependence of the anisotropy on the sign of spin temperature. A rich potential of a dynamical orientation for studying the magnetic structure of rare nuclei and the dynamics of their spin-spin interactions in dielectric host materials is demonstrated. Physical and technological advantages and disadvantages of the method in the on-line regime of the implantation of heavy nuclei are discussed.     

Elastic and inelastic proton scattering on 7Li nuclei within diffraction theory

On the basis of Glauber diffraction theory, the differential cross sections and analyzing powers are calculated for elastic and inelastic (to the $J^\pi = \frac{{1^ - }}{2}$ level at E ^* MeV) proton scattering on ⁷Li nuclei at E _p=0.2, 0.6, and 1.0 GeV. In this calculation, the ⁷Li wave function is taken in the αt model. The sensitivity of our results to variations in the parameters of the elementary pN and pα amplitudes is investigated. Effects induced by multiple scattering on the target-nucleus clusters are shown to play a significant role. Theoretical results are found to comply well with experimental data available only at E _p=0.2 GeV.     

Molecular mobility in protein solutions containing metal ions with various ionic radii

Using methods of photon-correlation spectroscopy and polarized fluorescence pH, the dependencies of the translation and rotary diffusion coefficients of collagen and bovine serum albumen in solutions on NaCl and KCl salts at various ion forces have been obtained. It is shown that the size of the metal ionic radius affects intermolecular interactions and the mobility of albumen molecules in solution. The effect of the potassium ion, with its large ionic radius, compared with Na ions, is analogous to the effect of heavy metals ions, since it results in albumen molecule aggregation near the isoelectric point.     

Characteristic behaviour of spontaneous polarization and dielectric constant of barium titanate containing cobalt ions

The temperature dependence of the dielectric constant and the spontaneous polarization as well as the effect of their thermal history has been investigated for BaTiO₃ crystals doped with Co. Experimental evidence for diffuse phase transitions (DPT) is found. Results are interpreted taking into account that in the crystal exists a relatively large amount of disorder which can be pictured as a change in the local configuration of substituted Co-ions.