Kurchatov Institute

About: Kurchatov Institute is a facility organization based out in Moscow, Russia. It is known for research contribution in the topics: Plasma & Neutron. The organization has 12493 authors who have published 18321 publications receiving 281837 citations. The organization is also known as: Laboratory No. 2 of the USSR Academy of Sciences & Kurchatov Institute.

Production of Σ(1385)± and Ξ(1530)0 in proton–proton collisions at s√= 7 TeV

Abstract: The production of the strange and double-strange baryon resonances (Sigma (1385)(+/-), Xi (1530)(0)) has been measured at mid-rapidity (vertical bar y vertical bar < 0.5) in proton-proton collisions at root s = 7 TeV with the ALICE detector at the LHC. Transverse momentum spectra for inelastic collisions are compared to QCD-inspired models, which in general underpredict the data. A search for the phi (1860) pentaquark, decaying in the Xi pi channel, has been carried out but no evidence is seen.

Turbulent transport reduction by E×B velocity shear during edge plasma biasing: recent experimental results

Abstract: Experiments in the tokamaks TEXTOR, CASTOR, T-10 and ISTTOK, as well as in the reversed field pinch RFX have provided new and complementary evidence on the physics of the universal mechanism of E×B velocity shear stabilization of turbulence, concomitant transport barrier formation and radial conductivity by using various edge biasing techniques. In TEXTOR the causality between transport reduction and induced electric fields in the edge has been for the first time clearly demonstrated. The high electric field gradients have been identified as the cause for the quenching of turbulent cells. A quantitative analysis of the measured transport reduction is in good agreement with theoretical predictions. The scaling of plasma turbulence suppression with velocity shear has been established, revealing the density-potential cross-phase as a key element. Reduction in poloidal electric field, temperature, and density fluctuations across the shear layer lead to a reduction of the anomalous conducted and convected heat fluxes resulting in an energy transport barrier that is measured directly. In CASTOR the biasing electrode is placed at the separatrix in a non-intrusive configuration which has demonstrated strongly sheared electric fields and consequent improvement of the global particle confinement, as predicted by theory. The impact of sheared E×B flow on edge turbulent structures has been measured directly using a comprehensive set of electrostatic probe arrays as well as emissive probes. Measurements with a full poloidal Langmuir probe array have revealed quasi-coherent electrostatic waves in the SOL with a dominant mode number equal to the edge safety factor. In T-10 edge biasing is clearly improving the global performance of ECR heated discharges. Reflectometry and heavy ion beam probe measurements show the existence of a narrow plasma layer with strong suppression of turbulence. On ISTTOK, the influence of alternating positive and negative electrode and (non-intrusive) limiter biasing has been compared. Electrode biasing is found to be more efficient in modifying the radial electric field Er and confinement, limiter biasing acting mainly on the SOL. In the RFX reversed field pinch it has been demonstrated that also in RFPs biasing can increase the local E×B velocity shear in the edge region, and hence substantially reduce the local turbulence driven particle flux mainly due to a change in the relative phase between potential and density fluctuations.

First Measurement of Near-Threshold J /ψ Exclusive Photoproduction off the Proton

Abstract: We report on the measurement of the γ p → J / ψ p cross section from E γ = 11.8 GeV down to the threshold at 8.2 GeV using a tagged photon beam with the GlueX experiment. We find that the total cross section falls toward the threshold less steeply than expected from two-gluon exchange models. The differential cross section d σ / d t has an exponential slope of 1.67 ± 0.39 GeV − 2 at 10.7 GeV average energy. The LHCb pentaquark candidates P + c can be produced in the s channel of this reaction. We see no evidence for them and set model-dependent upper limits on their branching fractions B ( P + c → J / ψ p ) and cross sections σ ( γ p → P + c ) × B ( P + c → J / ψ p ) .

Structure of X-ray photoelectron spectra of lanthanide compounds

Abstract: The results of the X-ray photoelectron spectroscopy studies of the electronic structures of trifluorides, oxides and other compounds of Sc, Y and lanthanides (Ln) from La to Lu, except for Pm, in the binding energy range from 0 to 1350 eV are generalised. The established dependences of the Ln4f binding energies and the relative intensities of lines on the atomic number Z do not contradict the theoretical data stating that the Ln4f atomic orbitals (AO) participate markedly in the formation of molecular orbitals (MO) in the lanthanide compounds. It is established that inner valence molecular orbitals (IVMO) composed of the metal Sc3p, Y4p, Ln5p AO and the ligand L(O,F)2s AO are formed in these systems in addition to the outer valence molecular orbitals (OVMO). It is shown that the spectral fine structure caused by multiplet splitting, many-body perturbation and dynamic effects is correlated with the lanthanide oxidation state, the spin state of ions and the mechanisms of the secondary electronic processes accompanying the photoemission and can serve as a characteristic for identification of lanthanide compounds. Charge induction is discussed using titanium and niobium double oxides as examples. The bibliography includes 206 references.

Stability of standing matter waves in a trap

Abstract: We discuss excited Bose-condensed states and find the criterion of dynamical stability of a kinkwise state, i.e., a standing matter wave with one nodal plane perpendicular to the axis of a cylindrical trap. The dynamical stability requires a strong radial confinement corresponding to the radial frequency larger than the mean-field interparticle interaction. We address the question of thermodynamic instability related to the presence of excitations with negative energy.