Nanosize Carbides Formation and Fatigue Life Increase of Stainless Steel by Electron Beam Treatment

Electron – beam treatment with 20 J/cm2 energy density of Fe-0.20C-23Cr-18Ni stainless steel increases fatigue life up to 2.1 times. Fracture surface investigations have been carried out by the methods of scanning and transmission diffraction electron microscopy and layer-by-layer analysis of structural phase states and defect substructure of steel subjected to the multicyclic fatigue tests, has been made as well. Nanosize (Cr,Fe)23C6 carbides formation and physical reasons of steel fatigue life increase by electron – beam treatment have been found out. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3480

Optimization of technology for fabrication of sectional nuclear radiation detectors based on high-resistance silicon

On the basis of experimental studies the surface-barrier technology for fabrication of sectional nuclear radiation detectors with using of the high-resistance n-Si plates of large diameter (~ 100 mm) was optimized. The 9-sectional detector matrixes were manufactured. In such matrix each section is a separate detector with the thickness of sensitive area W ≤ 350 μm, the working area S = 4 cm², and the energy resolution R = 50…75 keV under irradiation by three-component α-source. The electrophysical and spectrometric characteristics of the sectional silicon detectors were determined. The manufactured detectors can be used in the nuclear experiments involving heavy ions at the low yields of reaction products.На основі проведених експериментальних досліджень оптимізовано поверхнево-бар'єрну технологію виготовлення секційних детекторів ядерних випромінювань з використанням пластин високоомного n-Si великого діаметра (~ 100 мм). Виготовлено 9-секційні детекторні матриці, де кожна секція є окремим детектором з товщиною чутливої області W ≤ 350 мкм, робочою площею S = 4 см² та енергетичною роздільною здатністю R = 50…75 кеВ при опроміненні трикомпонентним α-джерелом. Визначено електрофізичні та спектрометричні характеристики секційних кремнієвих детекторів. Виготовлені детектори можуть бути використані в ядерних експериментах за участю важких іонів при низьких виходах продуктів реакцій.На основе проведенных экспериментальных исследований оптимизирована поверхностно-барьерная технология изготовления секционных детекторов ядерных излучений с использованием пластин высокоомного n-Si большого диаметра (~ 100 мм). Изготовлены 9-секционные детекторные матрицы, где каждая секция является отдельным детектором с толщиной чувствительной области W ≤ 350 мкм, рабочей площадью S = 4 см² и энергетическим разрешением R = 50…75 кэВ при облучении трехкомпонентным α-источником. Определены электрофизические и спектрометрические характеристики секционных кремниевых детекторов. Изготовленные детекторы могут быть использованы в ядерных экспериментах с участием тяжелых ионов при низких выходах продуктов реакций

Measurement of the Ds lifetime

We report precise measurement of the Ds meson lifetime. The data were taken by the SELEX experiment (E781) spectrometer using 600 GeV/c Sigma-, pi- and p beams. The measurement has been done using 918 reconstructed Ds. The lifetime of the Ds is measured to be 472.5 +- 17.2 +- 6.6 fs, using K*(892)0K+- and phi pi+- decay modes. The lifetime ratio of Ds to D0 is 1.145+-0.049.Comment: 5 pages, 2 figures submitted to Phys. Lett.

Confirmation of the Double Charm Baryon Xi_cc+ via its Decay to p D+ K-

We observes a signal for the double charm baryon Xi_cc+ in the charged decay mode Xi_cc+ -> p D+ K- to complement the previously reported decay Xi_cc+ -> Lambda_c K- pi+ in data from SELEX, the charm hadro-production experiment (E781) at Fermilab. In this new decay mode we observe an excess of 5.62 events over an expected background estimated by event mixing to be 1.38+/-0.13 events. The Poisson probability that a background fluctuation can produce the apparent signal is less than 6.4E-4. The observed mass of this state is (3518+/-3)MeV/c^2, consistent with the published result. Averaging the two results gives a mass of (3518.7+/-1.7)MeV/c^2. The observation of this new weak decay mode confirms the previous SELEX suggestion that this state is a double charm baryon. The relative branching ratio Gamma(Xi_cc+ -> pD+K-)/Gamma(Xi_cc+ -> Lambda_c K- pi+) = 0.36+/-0.21.Comment: 11 pages, 6 included eps figures. v2 includes improved statistical method to determine significance of observation. Submitted to PL

Proximity effect at superconducting Sn-Bi2Se3 interface

We have investigated the conductance spectra of Sn-Bi2Se3 interface junctions down to 250 mK and in different magnetic fields. A number of conductance anomalies were observed below the superconducting transition temperature of Sn, including a small gap different from that of Sn, and a zero-bias conductance peak growing up at lower temperatures. We discussed the possible origins of the smaller gap and the zero-bias conductance peak. These phenomena support that a proximity-effect-induced chiral superconducting phase is formed at the interface between the superconducting Sn and the strong spin-orbit coupling material Bi2Se3.Comment: 7 pages, 8 figure

Centrality Dependence of the High p_T Charged Hadron Suppression in Au+Au collisions at sqrt(s_NN) = 130 GeV

PHENIX has measured the centrality dependence of charged hadron p_T spectra from central Au+Au collisions at sqrt(s_NN)=130 GeV. The truncated mean p_T decreases with centrality for p_T > 2 GeV/c, indicating an apparent reduction of the contribution from hard scattering to high p_T hadron production. For central collisions the yield at high p_T is shown to be suppressed compared to binary nucleon-nucleon collision scaling of p+p data. This suppression is monotonically increasing with centrality, but most of the change occurs below 30% centrality, i.e. for collisions with less than about 140 participating nucleons. The observed p_T and centrality dependence is consistent with the particle production predicted by models including hard scattering and subsequent energy loss of the scattered partons in the dense matter created in the collisions.Comment: 7 pages text, LaTeX, 6 figures, 2 tables, 307 authors, resubmitted to Phys. Lett. B. Revised to address referee concerns. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are publicly available at http://www.phenix.bnl.gov/phenix/WWW/run/phenix/papers.htm

Measurement of W Polarisation at LEP

The three different helicity states of W bosons produced in the reaction e+ e- -> W+ W- -> l nu q q~ at LEP are studied using leptonic and hadronic W decays. Data at centre-of-mass energies \sqrt s = 183-209 GeV are used to measure the polarisation of W bosons, and its dependence on the W boson production angle. The fraction of longitudinally polarised W bosons is measured to be 0.218 \pm 0.027 \pm 0.016 where the first uncertainty is statistical and the second systematic, in agreement with the Standard Model expectation

Search for Anomalous Couplings in the Higgs Sector at LEP

Anomalous couplings of the Higgs boson are searched for through the processes e^+ e^- -> H gamma, e^+ e^- -> e^+ e^- H and e^+ e^- -> HZ. The mass range 70 GeV < m_H < 190 GeV is explored using 602 pb^-1 of integrated luminosity collected with the L3 detector at LEP at centre-of-mass energies sqrt(s)=189-209 GeV. The Higgs decay channels H -> ffbar, H -> gamma gamma, H -> Z\gamma and H -> WW^(*) are considered and no evidence is found for anomalous Higgs production or decay. Limits on the anomalous couplings d, db, Delta(g1z), Delta(kappa_gamma) and xi^2 are derived as well as limits on the H -> gamma gamma and H -> Z gamma decay rates

Measurement of W Polarisation at LEP

The three different helicity states of W bosons produced in the reaction e+ e- -> W+ W- -> l nu q q~ at LEP are studied using leptonic and hadronic W decays. Data at centre-of-mass energies \sqrt s = 183-209 GeV are used to measure the polarisation of W bosons, and its dependence on the W boson production angle. The fraction of longitudinally polarised W bosons is measured to be 0.218 \pm 0.027 \pm 0.016 where the first uncertainty is statistical and the second systematic, in agreement with the Standard Model expectation