Plasma diagnostics in the optical and X-ray regions on the plasma focus device PF-4 (installation Tyulpan)

The results of experiments received on the plasma focus (PF) device with energy stored equal 4 kJ are represented. Photos of the current plasma sheath (CPS), pre-pinch, sphere-like plasma formations are produced with the help of the electron-optical converter contained a gated micro-channel plate (MCP) and the CCD-camera imaging system in the visible region. The redial velocity of the CPS is about 10⁷ cm/s. Neon plasma electron density measured with the help of the interferograms in the visible region and the spectrums in the soft X-ray region equals 3·10¹⁸ cm⁻³. Electron temperature equals about 200 eV. Discharge integral photos were obtained with the help of the soft X-ray pinhole camera. Pictures with 2 μs resolution of the plasma luminescence above PF anode region were made by CCD-camera

Program and algorithmic complex for synthesis of dynamic photo analysis of the aging degree of rubbers

The article describes program and algorithmic complex for synthesis of computer vision. This method operates as part of an automated control system for climate testing and it designs to analyze the aging of rubber products according to their visual indices. In this article the structural scheme of the system has been given. In addition, modified methods have been described. They compare the coordinates of a series of photographs, eliminate noise in the image being processed, and convert the output data of the computer vision algorithms into aging characteristics of rubbers. A brief description of the software of the operator-researcher has been presented.The authors express their gratitude to the members of the "Chemistry and Chemical Technology of organic compounds and polymers processing" department of "Voronezh State University of Engineering Technology" Prof. Karmanova O.V. and Dr. Molchanov V.I. for their valuable advice, training and providing of experimental samples of rubber as well as Dr. Rebrikov D.I. for assistance in carrying out the experimental research

Moduli of symplectic instanton vector bundles of higher rank on projective space P3

Symplectic instanton vector bundles on the projective space P3 constitute a natural generalization of mathematical instantons of rank 2. We study the moduli space In,r of rank-2r symplectic instanton vector bundles on P3 with r 65 2 and second Chern class n 65 r, n 61 r(mod2). We give an explicit construction of an irreducible component In 17,r of this space for each such value of n and show that In 17,r has the expected dimension 4n(r + 1) 12 r(2r + 1). \ua9 2012 Versita Warsaw and Springer-Verlag Wien

Plasma focus installation as a tool for the study of the interaction of high power plasma streams with condensed matter

In this work the possibilities of the use of the high-current discharges of Plasma Focus type for the investigation of the effect of plasma on the materials are discussed. From this point of view the properties of plasma streams and ion beams arising in the PF discharges are studied. Here, as an example of an application of the Plasma Focus device (PF), we studied the influence on Vanadium (perspective material in nuclear power engineering) a cumulative streams producing in the P

Laser shadow and interferometric investigation of the structure and dynamics of plasma in PF-3 facility

The work presents the laser investigation of a plasma focus discharge in neon. This investigation was done in connection with the recently discussed possibility of the use of such type of discharges for the creation of the soft X-ray source and its application for the compression of the solid targets (liners). Some features of a plasma focus discharge in 2.8 MJ Plasma Focus such as a complicated structure of current-plasma sheath (CPS), its relation to soft X-ray (SXR) pulse emitted from a pinching region were studied by developed laser diagnostics.У роботі представлене лазерне дослідження плазмово-фокусного розряду в неоні на установці ПФ-3. Дослідження були виконані в зв'язку з обговорюваною останнім часом можливістю використання такого типу розрядів для створення могутніх джерел м'якого рентгенівського випромінювання і їх застосування для стиску твердих мішеней (лайнерів). Деякі особливості плазмово-фокусного розряду в установці ПФ-3 такі, як складна структура струмо-плазмової оболонки і її зв'язок із властивостями імпульсу м'якого рентгенівського випромінювання, випромінюваного з області пінчування плазми, досліджені за допомогою розробленої лазерної діагностики.В работе представлено лазерное исследование плазмофокусного разряда в неоне на установке ПФ-3. Исследования были выполнены в связи с обсуждаемой в последнее время возможностью использования такого типа разрядов для создания мощных источников мягкого рентгеновского излучения и применения их для сжатия твердых мишеней (лайнеров). Некоторые особенности плазмофокусного разряда в установке ПФ-3 такие, как сложная структура токово-плазменной оболочки и ее связь со свойствами импульса мягкого рентгеновского излучения, излучаемого из области пинчевания плазмы, исследованы с помощью разработанной лазерной диагностики

Kaon Production and Kaon to Pion Ratio in Au+Au Collisions at \snn=130 GeV

Mid-rapidity transverse mass spectra and multiplicity densities of charged and neutral kaons are reported for Au+Au collisions at \snn=130 GeV at RHIC. The spectra are exponential in transverse mass, with an inverse slope of about 280 MeV in central collisions. The multiplicity densities for these particles scale with the negative hadron pseudo-rapidity density. The charged kaon to pion ratios are $K^+/\pi^- = 0.161 \pm 0.002 {\rm (stat)} \pm 0.024 {\rm (syst)}$ and $K^-/\pi^- = 0.146 \pm 0.002 {\rm (stat)} \pm 0.022 {\rm (syst)}$ for the most central collisions. The $K^+/\pi^-$ ratio is lower than the same ratio observed at the SPS while the $K^-/\pi^-$ is higher than the SPS result. Both ratios are enhanced by about 50% relative to p+p and $\bar{\rm p}$+p collision data at similar energies.Comment: 6 pages, 3 figures, 1 tabl

Azimuthal anisotropy at RHIC: the first and fourth harmonics

We report the first observations of the first harmonic (directed flow, v_1), and the fourth harmonic (v_4), in the azimuthal distribution of particles with respect to the reaction plane in Au+Au collisions at the Relativistic Heavy Ion Collider (RHIC). Both measurements were done taking advantage of the large elliptic flow (v_2) generated at RHIC. From the correlation of v_2 with v_1 it is determined that v_2 is positive, or {\it in-plane}. The integrated v_4 is about a factor of 10 smaller than v_2. For the sixth (v_6) and eighth (v_8) harmonics upper limits on the magnitudes are reported.Comment: 6 pages with 3 figures, as accepted for Phys. Rev. Letters The data tables are at http://www.star.bnl.gov/central/publications/pubDetail.php?id=3

Pion, kaon, proton and anti-proton transverse momentum distributions from p+p and d+Au collisions at sNN=200\sqrt{s_{NN}} = 200 GeV

Identified mid-rapidity particle spectra of $\pi^{\pm}$, $K^{\pm}$, and $p(\bar{p})$ from 200 GeV p+p and d+Au collisions are reported. A time-of-flight detector based on multi-gap resistive plate chamber technology is used for particle identification. The particle-species dependence of the Cronin effect is observed to be significantly smaller than that at lower energies. The ratio of the nuclear modification factor ($R_{dAu}$) between protons $(p+\bar{p})$ and charged hadrons ($h$) in the transverse momentum range $1.2<{p_{T}}<3.0$ GeV/c is measured to be $1.19\pm0.05$(stat)$\pm0.03$(syst) in minimum-bias collisions and shows little centrality dependence. The yield ratio of $(p+\bar{p})/h$ in minimum-bias d+Au collisions is found to be a factor of 2 lower than that in Au+Au collisions, indicating that the Cronin effect alone is not enough to account for the relative baryon enhancement observed in heavy ion collisions at RHIC.Comment: 6 pages, 4 figures, 1 table. We extended the pion spectra from transverse momentum 1.8 GeV/c to 3. GeV/

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02